Copyright © 2003-2010, Gerard Putter
Copyright © 2003-2010, Gerard Putter
Introduction
About the ROM image file
Run a demo to test the installation
Where to find Apple II documentation
About the evaluation version and licensed versions
Starting and stopping the program
General operation
The Apple ][ keyboard
Working with disk images
5.25" floppy disk drive
Hard disk and 3.5" floppy disk drive
Printer
Serial interface
Cassette recorder
80-column card for the Apple ][ and Apple ][+
80-column display on the Apple //e
AppleMouse
Real time clock
Z80 card and CP/M
Joystick and game paddles
Working with sound
Using different screen sizes and fullscreen
Recording a movie
The A2V2 utility program
Working with character sets and international keyboards
Configuration
Controlling Virtual ][ with AppleScript
The Virtual ][ Inspector
Getting support
How you can contribute to Virtual ][
Release notes
Specifications of the virtual machine
Unsupported features
Why did I create this application?
Acknowledgements
Virtual ][ is a program that emulates the Apple ][ computer. Its main purpose is to enjoy, on your Macintosh computer, the nostalgic fun of the Apple ][.
Key featuresVirtual ][ accurately implements the hardware of the original machine in software, so all programs should behave like they did on the real machine.
The program requires Mac OS X 10.4 "Tiger" or better. There are no specific hardware requirements: the program runs on any Macintosh that is able to run Mac OS X.
Note that, for reasons of copyright, the application does not come with the original Apple ROM images. For more information on this, read "About the ROM image file".
You can download and try an evaluation version of Virtual ][ for free. If you like the program, you can buy a license and enjoy the full-featured Apple ][ emulation. Read more about this in "About the evaluation version and licensed version".
The first time you start Virtual ][, you'll probably see a notice about a missing ROM image file. Virtual ][ can emulate three different machines: the Apple ][, the Apple ][+ and the Apple //e. Each machine needs a different ROM. This is how to install one or more ROM files.
In each Apple ][, the memory address range from $D000
to $FFFF is occupied by ROM, containing the Basic interpreter (either
Integer Basic or Applesoft Basic) and the system monitor. In the
Apple //e, part of the memory range $C100 - $CFFF is also used
for ROM.
Virtual ][ needs a valid ROM image file to behave like a
real Apple II. Because the ROM's are copyrighted by
Apple, they are not bundled with Virtual ][. The ROM's
must be present as external files containing the exact memory image.
To be more precise: Virtual ][ uses the last 12 KB of
the designated file (16 KB in the case of Apple //e) as the ROM of a
newly created virtual machine.
If the program does not find the ROM file, it uses a built-in ROM
image, which is only able to issue the notice on the missing ROM
image file.
If you want to use a non-standard ROM, and know what you are doing, you can override the standard ROM image file search, and specify a ROM image file in the "ROM memory" section of the configuration window.
After you have installed the ROM image files, you can immediately test whether the installation was successful, and see some of the program's highlights at the same time.
To that purpose, click on the Applescript menu, and select any of the "example scripts".
You'll see a short explanation of what the demo will do; when you click the "Run" button the demo will start.
If you want to learn more about using Applescript with Virtual ][, you should read Controlling Virtual ][ with AppleScript
This Help file explains everything about using the
Virtual ][ program. It tells you for example how to
configure a virtual machine, how to use the emulated printer and
how to work with disk images.
It does, however, not explain how to use the
Apple II computer. If you want to refresh your memory on
Applesoft Basic, Integer Basic, DOS or ProDOS commands, you might
find this web page useful: Apple ][
Programmer's reference. Or, if you want more detailed information,
have a look at this site; it contains
a large collection of Apple II manuals.
The program runs in one of three license modes:
This table shows the difference between the licenses:
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"Evaluation Version" watermark in screen |
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Pauses every five minutes |
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Full use of matrix printer emulation (without "Evaluation Version" watermark) |
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Record a movie of the emulated screen |
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Can mount a Mac folder as a ProDOS disk |
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Maximum amount of emulated memory |
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You're entitled to all future improvements of the program |
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Intelligent power management (as described in Setting the speed) |
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Can resume a machine from a previous session |
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A license gives you the right to run Virtual ][ on
one computer at a time (you can install it on multiple
computers though).
Buying a license is easy. Just click on the button below, or choose
"Buy a License" from the application menu in Virtual ][.
Either option will take you to the website of the Kagi store. There
you can choose to buy the limited license, the full license or an
upgrade from limited to full.
As soon as you have paid for the license, Kagi sends you an e-mail
containing a license code. Choose "Enter License Code" in the
Virtual ][ application menu, and enter the information
received in the e-mail.
When everything checks out, the program is upgraded to the licensed
version immediately. There is no need to stop and restart the
program.
There are two ways to start the Virtual ][ application:
In either case, the program requires a ROM image file to boot a virtual machine. This is described in more detail in "About the ROM image file". Assuming a valid Apple //e ROM image is available and the program is started by double-clicking the application icon, it creates a default virtual machine and shows the main window.
A virtual machine stops (is "switched off") when you close its window (or when you stop the Virtual ][ program). When you do, the program presents a sheet asking if it should save the virtual machine.
Instead of saving the complete machine state, you can also choose to just save the machine configuration. When you open a file saved this way, a machine is constructed with the configured components, and the machine is "switched on". In this case it does not continue a previous run, but starts from scratch.
The "default machine" defines the type of virtual machine the program creates when it is started. You can easily configure the program to use a default configuration of your choice. To save the current machine as the default, select the option "Make This the Default Configuration" in the Machine menu. Alternatively, select "Preferences" from the Virtual ][ menu. The preferences window allows you to select a pre-configured machine as the default.
If you never want to save the state of a running virtual machine, you can tell the program to skip the "save state" sheet when a virtual machine is closed. When this option is selected, you can always change your mind and still save the machine state by holding down the "ctrl" key while closing the window.
This is what the main window looks like when the program is started, assuming the correct ROM image has been installed. On your Mac the window might look slightly different, because Virtual ][ initially determines a window size that best matches your screen.
The main part of the window is the Apple ][ screen.
In the example it emulates a monochrome green monitor, but the
leftmost two buttons in the toolbar make it easy to show a color
monitor, or to change "green" to a different color (like amber).
The screen as shown in the example is what an Apple //e shows
when it is turned on: it waits for a bootable diskette. You can get
the Applesoft prompt by pressing Reset (emulated by control-F12 or
the Reset button in the toolbar).
The bottom part of the window is a "drawer" that shows the connected
devices. The devices in the default configuration are:
Furthermore, the drawer contains four small icons at the left; this is the "media" section, representing diskettes and cassette tapes. Each icon in the devices drawer actually is a button. The way these buttons and the devices work is described in the next chapters.
This is what the default configuration looks like. The default machine is an Apple //e with
You can change the configuration to your liking, as explained in the "Configuration" section.
The contents of the Apple ][ screen can be copied to the Macintosh clipboard. This can be done in two ways:
A virtual machine can temporarily be paused by selecting "Freeze Virtual Machine" from the "Machine" menu, or by clicking the "Freeze" button in the toolbar. You can later on resume with "Resume Virtual Machine" or the same toolbar button. As a shortcut you can also use the F1 key to pause / resume.
Virtual ][ faithfully emulates the speed of the original Apple machines, which was 1 MHz. Maintaining this exact speed is essential for programs that display animated graphics or produce sound. There are however situations where it would be nice to have a greater processing speed: while doing a lengthy calculation for example, or when accessing the floppy disk. To this purpose Virtual ][ has three modes of operation, which you can choose from the Machine menu or using the little "Speed" wheel in the toolbar.
If you have the full license version of Virtual ][, the high speed and
maximum speed settings come with a power management feature: while the Apple II is "idle",
in other words if it isn't doing anything useful, the speed is automatically reduced to "regular".
This saves energy and enhances the battery life on a notebook Mac.
If you want, you can switch the power management feature off with the menu item
"Regular Speed if Apple II is Idle", in the Machine menu.
Note that the highest effective speed that can be obtained depends on your Macintosh, on the number of simultaneously open virtual machines, and on other programs running at the same time.
You can preserve battery power even further by selecting the option "Pause virtual machines if minimized or hidden" in the "Power" section of the application preferences. The option is switched on by default.
The built-in keyboard of the Apple ][ computer has far less keys than a standard Macintosh keyboard. It even has hardly enough keys to produce the entire supported character set. For example, on the original machine the user had to press shift-M to produce the character "]", and shift-N for "^". The characters "[" and "\" could not be entered at all, although they were part of the character set.
These restrictions do not apply to the Virtual ][ emulator. All characters in the Apple ][ character set can be entered by typing the appropriate character on the Macintosh keyboard. This implies that shift-M just produces a capital M, not a "]".
The Apple ][ keyboard could not be used to enter
lowercase characters. Typing any of the letters "a" to "z" produced
uppercase "A" to "Z".
The Apple //e keyboard was able to enter uppercase and
lowercase characters, but many programs still expected uppercase
input only.
To emulate flexible keyboard behavior, Virtual ][ has
the "soft caps lock" option. When it is on, the keys "a" to "z"
produce uppercase letters, as on the original Apple ][
keyboard. When the option is off, these keys produce lowercase
letters (or uppercase when shift is also held down), as on the
Apple //e. This option can be toggled with the "Caps" toolbar
button.
The Apple ][ had four special keys that did not produce a character. Here is how they are emulated.
If the Macintosh clipboard contains text, it can be pasted into the virtual machine. The behavior is as if each individual character were typed on the keyboard. This "typing" occurs as fast as the Apple ][ can accept the characters, so no characters are lost in the process. If the Apple ][ is not reading the keyboard when the text is pasted, the text remains queued. Manual input is disabled as long as a pasted text is being entered into the Apple ][. A "newline" character in the text is converted to the "Return" key on the Apple ][.
A disk image is a representation, in a single Macintosh file, of an entire floppy disk or hard disk. Apple II disk image files come in several different formats; the next table shows the formats supported by Virtual ][.
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Disk image type |
File extension |
Description |
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5.25" diskette |
.dsk, .do, .po |
A regular diskette with 35 to 40 tracks, used with DOS, ProDOS, UCSD Pascal or CP/M. The size of the disk image file is 140 KB for a 35 track disk, up to 160 KB for a 40 track disk. |
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Copy protected 5.25" diskette |
.nib |
A disk in so-called "nibbilized" form. This is a low-level representation, which
allows for disks that were originally copy-protected. The format can also be used to
represent 13-sector disks (DOS 3.2). The size of a nib image is 232960 bytes for a
35 track disk, up to 266240 bytes for a 40 track disk.
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Copy protected 5.25" diskette (proprietary) |
.v2d |
A proprietary format, capable of supporting all features of the Disk ][, including "half-tracks" and tracks of non-standard length. The format is compatible with the "D5NI" format used by one of the first Apple II emulators, "Stop The Madness". You won't find disks with this format on the Internet, but Virtual ][ might create such a disk image when the other formats fall short. |
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Compressed 5.25" diskette |
.gz, .gzip |
Any of the above diskette types, compressed with the gzip utility. Many Internet archives offer diskettes in this form, to save space and bandwidth. Such files can directly be used in Virtuall ][, without the need to expand them first. |
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Hard disk or 3.5" diskette |
.2mg, .2img |
A widely used, universal disk image format. |
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Hard disk or 3.5" diskette (legacy format) |
.hdv |
A disk format based on one of the Mac Classic DiskCopy formats,
"NDIF R/W". If you have DiskCopy disk images, there is a good chance you can convert them to the .hdv
format by selecting "Convert Legacy Disk Images" from the Media menu. This starts a
utility program that allows you to select one or more disk image files and then tries to
convert them. When successful, the converted disk images are saved with the ".hdv"
extension in the same folder as the original. The original disk images remain untouched.
Note the conversion works one-way only.
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Apart from disk images, Virtual ][ also lets you mount a Macintosh folder as an
Apple ][ floppy disk or a ProDOS hard disk; this provides a way to
copy files from one environment to the other.
Another way to copy files from the Macintosh to the emulated Apple ][ environment and
vice versa is the application "ADFS" by David Cotter.
How do you obtain disk image files? First of all, you can find them on the Internet, for example in the Asimov archives.
However, Virtual ][ can also help you converting original Apple II diskettes to disk images, with the A2V2 utility program. If you still have an original Apple ][ with a working disk drive, Virtual ][ can help you converting original diskettes to disk image files. To this purpose, select "Convert Apple II Diskettes" from the "Media" menu. This will start a separate program, named A2V2 (short for Apple ][ - Virtual ][). Read the program's Help section to learn how to do the conversion. A2V2 can convert in both directions: from diskettes to disk image files and vice versa.
Because the capacity of an Apple ][ diskette is very small by todays standards (typically 140 KB), you might end up with many diskette image files. Virtual ][ offers several ways to keep track of the diskettes and their contents.
These options are discussed below.
If you don't have too many disk images, it is recommended to put all your disk images in one folder (with subfolders as necessary), and to make this the "favorite disk folder" in the Virtual ][ preferences. That way you can use the "Disks" button in the toolbar to open your disks folder in the Finder. Combined with Apple's Exposé this is a convenient way to locate disk images and drag them to an empty Virtual ][ disk drive.
A powerful mechanism offered by Virtual ][ is a built-in search window. It lets you find the disk images that contain an Apple II file with a specific name, no matter where these disk images are on your Mac. This works for diskette images with extension .dsk, .po or .do, and their gzipped equivalents. It also works for hard disk and 3.5" disk image files. This feature relies on Apple's Spotlight technology, so you must run OS X 10.4 "Tiger" or better, and the disk image files must be in folders that are included in the Spotlight search (by default your entire home folder, and everything in it, is included).
To use the feature, select "Search All Disk Images" from the "Media" menu.
When no disk image files appear at all, or when you feel there should be more disk images than are actualy shown, choose "Import Disk Images in Spotlight" from the Application menu. The search window will be updated while new disk images are found.
Initially, the window shows you all disk images belonging to the selected file systems (DOS, ProDos, etc.). You can narrow down the displayed collection by typing (part of) an Apple ][ file name in the search field and pressing return.For example, suppose you know you have the game "Raster Blaster" somewhere. but have no idea where exactly. Open the search menu, type the name you are looking for, and press return. This is what might appear.
Apparently, these disk images all contain a file with the requested name. To insert one of the disks in an emulated floppy disk drive, double-click its line, or drag it to a disk drive.
Because the search mechanism uses the Spotlight feature, you can also search disk images without starting Virtual ][, by just typing a file name in the system-wide Spotlight search field. Selecting one of the disk images from the Spotlight menu launches Virtual ][ with the selected disk inserted.
Note that when you select a disk image file in the Finder, and open the "Info" window, it shows you the Apple II file system.
Note further that so called "copy protected" disk images cannot be searched, because they usually have a non-standard file system. Such disks can however be used in Virtual ]['s emulated disk drives.
Virtual ][ contains a module for the QuickLook feature of Mac OS X Leopard. It is installed automatically with Virtual ][, and allows you to quickly inspect the contents of most Apple II diskette and hard disk images. In the Finder, select the Cover Flow view, as shown in the screen snapshot. Alternatively, select a disk image and press the space bar to go to the QuickLook view.
The original Apple Disk ][ accepts 5.25" diskettes with 35 tracks.
However, it was possible to move the disk drive arm to track 36, and some copy protection schemes
actually relied on this. Furthermore, disk drives existed (not made by Apple) that supported
40 tracks. In order to support a wide range of disk formats, the disk drive emulation of
Virtual ][ supports up to 40 tracks.
The 5.25" diskette image formats supported in Virtual ][ are listed here.
Apart form disk images, the disk drive accepts a Macintosh folder to be mounted as a DOS 3.3 diskette. This feature is described in more detail below.
In order for a disk image to be inserted in a disk drive it must
have the appropriate file extension: ".dsk", ".do", ".po", ".nib",
".v2d", "gz" or "gzip". Inserting a disk can be done in several ways: one is to click
the appropriate media button in the device drawer and then select the
disk image and the target drive in the file open panel that appears.
The same can be done by selecting "Insert Diskette Image" from the
"Media" menu.
In the file open panel you will also see a checkbox to make the disk
image a part of the configuration. This means that when you save the
configuration and later re-open it, the selected disk image is
already inserted in the disk drive. This allows you to make a
"turnkey" system, which automatically boots from an already inserted
disk.
A different way to insert a disk is to simply drag the disk image file or shared folder from its Finder window (or from the disk search window) to an empty disk drive. An empty disk drive can be recognized by the opened drive door. Using this technique, you can still make the disk part of the configuration by holding down the "alt" key while dropping the file or folder.
The third way to insert a diskette is to double-click its icon in the
Finder or in the disk search window. Note that double-clicking a gzip file
in the Finder is an exception: it will result in the file being
expanded by the gzip utility!
When double-clik a disk image, Virtual ][ will be started when it isn't
running already, and the diskette is inserted in the disk drive with the
highest slot number and the lowest drive number. This is the disk drive
used for booting the machine, so effectively you can boot a DOS session by
simply double-clicking the DOS boot diskette.
If Virtual ][ already runs when you double-click the
diskette image, it will be inserted in any free disk drive. When no such
drive is available, a new virtual machine will be created.
A disk can be removed by clicking on the disk drive. Note that a
disk can be removed while it is being used for I/O; this is of course
not recommended, just as with a real Apple ][!
If the disk image or mounted folder is part of the configuration, the
program presents a confirmation dialog. Ejecting the disk removes it
from the configuration.
A new, uninitialized disk can be inserted by clicking the "new disk" media button.
In the dialog that appears, specify the name of the disk and the target drive. Just as with the real Apple ][, the new disk must be initialized by the operating system before it can be used. The disk is saved as a ".dsk" disk image.
A Macintosh folder can be mounted as a DOS 3.3 diskette. This is
an easy way to share files between a virtual machine and the
Macintosh environment. What actually happens is that the files in the
folder are converted to Apple DOS format (if necessary) and stored on
a temporary (in-memory) disk image, which is inserted in a disk
drive. When files are modified in the virtual machine, they are
copied back (with conversion as necessary) to the Macintosh
folder.
This approach implies that the Macintosh folder to be mounted is limited to
the maximum diskette size DOS 3.3 can handle, which is approximately 200 KB.
Furthermore, it must contain only files, not subfolders. The file
names must adhere to the DOS 3.3 file name rules: the first character
must be alphabetic, the file name must contain at most 30 characters
and must not contain a comma. Virtual ][ checks on these
conditions and will refuse to mount the folder if the conditions are
not met.
In Apple DOS every file has a file type, such as A(pplesoft Basic), I(nteger Basic) or B(inary). In order to handle the files correctly, Virtual ][ must be aware of the DOS file type of every shared file. Furthermore, some files need conversion. A text file for example has different representations in Apple DOS and in OS X, so if you want to edit a DOS text file in the OS X environment it must be converted. Virtual ][ has a feature that allows you to specify the file type of each shared file, and the conversion rules if appropriate. A dialog window is automatically presented when a Macintosh folder is mounted that contains files with unknown DOS file type. You can also see the dialog when you choose "Assign Apple DOS Types" from the "Media" menu. This is what the dialog looks like:
The list presents all files and folders in the selected folder.
Invalid files are marked with a little red cross, as are folders.
Valid files that have already been assigned a DOS type have a green
dot. Files that have never been assigned a DOS type appear with the
exclamation mark icon, and are assigned type Binary by default.
You can use the popup menus in "Type" and "Macintosh Format" to
change the settings. The next table lists your options:
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DOS Type |
Macintosh Format |
Address |
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B (Binary) |
No Conversion: the file is stored in the Macintosh folder exactly as it is stored on the DOS diskette. |
Not Applicable |
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B (Binary) |
Strip Prefix: in Apple DOS, all binary files have a 4 byte prefix, containing the load address and the length of the file. With this option, the prefix is omitted from the stored Macintosh file. |
This specifies the load address to be used when converting the file to DOS format. You can enter a decimal number or a hexadecimal number preceded by '$'. So for example $2000 is the same as 8192. |
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T (Text) |
No Conversion: the file is stored in the Macintosh folder exactly as it is stored on the DOS diskette. |
Not Applicable |
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T (Text) |
Macintosh Text: in Apple DOS, text files are encoded differently than on Macintosh. Select this option if you want to be able to edit the text file in the OS X environment. |
Not Applicable |
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A (Applesoft Basic) |
Always copied without conversion. |
Not Applicable |
Virtual ][ remembers the file types and conversion rules you assign, and it automatically uses these settings the next time the folder is mounted.
Note there are some special considerations when using shared folders:
When a disk is modified by the Apple ][ software, the corresponding disk image file or mounted folder is not updated right away. The changes are kept in memory, and are written to the file at regular time intervals of about 30 seconds. The contents of the disk are also written when the disk is removed from the drive or when the virtual machine window is closed. Virtual ][ tries to save the disk image in the format it already has, or in format ".dsk" if it is a freshly initialized disk. If this operation fails, the program tries to save the image in one of the other formats and changes the extension of the image file accordingly.
A disk image can be made write-protected by opening its Info window in the Finder and checking "Locked". This is the equivalent of closing the write-protect notch on a real diskette.
Hard disks and 3.5" floppy disks share the same technical characteristics, and Virtual ][ supports both with an imaginary type of emulated disk drive, called "OmniDisk". This device can handle disk images of any size up to 32 MB (the maximum supported by ProDOS), including 400 KB and 800 KB floppy disk images.
The hard disk / 3.5" disk image formats supported by Virtual ][ are listed here.
Apart form disk images, the OmniDisk accepts a Macintosh folder to be mounted as a ProDOS hard disk. This allows for an easy way to exchange files between the Apple ][ and the Macintosh environments. Note this feature requires a full license to be fully functional.
An OmniDisk must be connected to an emulated SCSI card, which fits in any free slot except slot 0. One SCSI card can control up to two OmniDisk drives. Refer to the chapter "configuration" for a description of how to insert an emulated card and connect devices to it.
Disk images can be inserted and ejected just like floppy disk
images.
The main difference is you use the OmniDisk buttons in the devices
view.
A Macintosh folder can be used as a ProDOS disk by "inserting" it in an OmniDisk drive. You can do this in two ways: either choose "Mount Folder as ProDOS Disk" from the "Media" menu, or simply drag a folder from the Finder to an empty OmniDisk in Virtual ][. Note that completing the operation might take a few seconds; the program has to plough through all files and sub-folders to determine the exact structure of the newly mounted disk.
A few restrictions apply to the mounted folder:
These restrictions are imposed by the ProDOS system. When Virtual ][ finds these conditions are not met, it will refuse to mount the folder.
While the folder is mounted, it is not accessible from the Finder. You'll notice the icon gets a lock and a "no entry" sign to indicate this.
Note that the mounted folder only works under ProDOS.
Every file and every folder in the mounted folder will be present on the ProDOS disk; any changes made on the ProDOS disk (like making new files and directories or changing existing files) result in the same change in the Macintosh folder. Note that a Macintosh file might have a name that is not allowed in ProDOS; in that case Virtual ][ composes an alternative name for use in ProDOS, but this name will be as close to the original as possible. The Macintosh file extension is used to determine the ProDOS file type. For example, ".BAS" is an Applesoft basic program, and ".TXT" is a text file.
The contents of text files are treated in a special way: the Apple ][ software expects each line to end with a carriage return character (ASCII 13), while Mac OS X expects a linefeed character (ASCII 10) to end a line. Virtual ][ automatically converts these codes while reading and writing text files. All other file types are stored in the Macintosh folder without any conversion.
When you use ProDOS to delete files or directories, the same items are deleted from the Macintosh folder. However, as you would expect on the Mac, they are not deleted right away but moved to the trash.
The mounted ProDOS folder disk is almost 100% compatible with a "real" ProDOS disk. You can even format it and install the ProDOS system on it, which will give you a bootable disk. The only thing not supported is making a full disk copy (block-by-block) to a mounted ProDOS folder disk. An attempt to do so will result in an error message.
You can store the state of a virtual machine while a folder is mounted as a ProDOS disk; in that case the folder will keep its access restrictions, because making any changes to the folder would render the saved state invalid and useless. When you open the saved state later on, the folder is mounted automatically and you can continue where you left off.
The restricted access to a mounted folder is lifted when you eject the disk by clicking the OmniDisk icon.
From that point you'll have full access to the folder again in the Macintosh environment.
So what if Virtual ][ crashes while a folder is mounted? In that case the disk wasn't ejected,
so the folder is inaccessible, and you won't be able to mount it again. To solve this, Virtual ][
has an option to reset the state of a mounted folder; you'll find it in the "Media" menu as "Reset Mounted ProDOS Folder".
Use it in case of emergency only!
Finally, the mounted ProDOS folder is only fully functional when you purchased a full license for Virtual ][. If you don't have such a license, you can still mount a folder, and examine the directories in ProDOS, but you cannot read or write any files.
Virtual ][ supports four different emulated printers:
The printer is represented by a "Printer" button in the devices drawer. While the Apple ][ is printing, the green light on the printer blinks. When you press the button, the printer goes offline and the program shows a print preview. You can also click the button with the "alt" key held down: this just sets the printer offline without showing the preview. Pressing the button a second time sets the printer online again.
The Epson FX-80 was a very popular printer in the 1980's, and is
therefore supported by many Apple ][
programs.
A printer on the Apple ][ must always be connected via a printer
interface card. When you want to use the Epson printer, insert an emulated
Grappler+ card in any slot (traditional was to use slot #1) and connect the
Epson printer to it. Read the section on Configuration
for more information on how to do this.
The emulation supports most of the functions of the original printer,
such as different character pitches, bold, italic and underlined
text, margins, tabs, and graphic modes. Actually the only feature
not supported is printing proportional characters.
The technology used by the emulator for text rendering is very
different from the technology used in the original Epson. As a
result, the characters are somewhat different, but the size and
looks of the characters are just like the real thing, as this example shows:
Apart from all Epson built-in character types, the emulation is
also able to print graphics. This allows you to run a program like
Broderbund's PrintShop.
Using the Epson printer is straightforward. While the Apple ][ is printing, the green light on the "Printer" button blinks. When printing has finished, click the Printer button to see a preview.
While the preview is open, the printer is offline, so the
Apple ][ will hold new output. The printer comes back
online when the preview sheet is closed.
The preview shows the printed output on one or more pages of fanfold
paper. The length of one page can be chosen in the Printer section of
the Configuration panel, and is 11 inches by default.
Two blue triangles, on the left and right hand side of the paper,
indicate the "current position": this is where the next line of
output will appear.
At the bottom of the sheet are a few buttons:
After saving the output to a pdf file you can use Apple's Preview program or Adobe Acrobat Reader to view the output or print it on a real printer.
The "Action" menu in the preview sheet contains a number of special options.
The Printer section of the Configuration panel lets you set additional printer options, corresponding with the "DIP switches" in the original printer.
From a user perspective, the ImageWriter II is very much like the Epson FX-80.
Both are capable of printing text in different styles, and both can print graphics. From
a technical perspective however, the printers are quite different. As a result,
some Apple II programs are compatible with just one of these printers. For example
the "MousePaint" program, which came with the Apple Mouse, can only print on the
ImageWriter, not on the Epson.
The ImageWriter II printer must be connected via a serial interface card.
When you want to use the ImageWriter II, insert an emulated
"serial printer card" in any slot (traditional was to use slot #1) and connect the
printer to it. Read the section on Configuration
for more information on how to do this. Note that the serial printer card is actually
the Apple super serial card, pre-configured to be used with this printer.
The ImageWriter II did have a unique feature, not found in the Epson, namely the
ability to print colors when a color ribbon was installed. This feature is fully
supported by Virtual ][.
The ImageWriter II allowed the user to select three different print
qualities: draft, correspondence, and near letter quality (NLQ). The emulation only
supports the "correspondence" setting, which is the most versatile and has less
restrictions than the other two. Note that text is printed with the Macintosh font
rendering engine, which in practice gives even better results than NLQ on the
original printer.
Operating the ImageWriter in Virtual ][ is identical to operating the Epson priner, so refer to the previous section for details.
This printer can be connected to either the Grappler+ or the serial printer card. It writes all printed output to an ASCII text file. When printing is finished, or even during printing, you can open the file and process it in whatever way is useful. The name of the printer file is of the form "Printer x - slot y.txt". In this name, x is simply a number starting at 1; y is the slot number the printer is connected to. All printer files are created on the desktop; the location cannot be configured. If a printer file with the same name already exists, new printed output is appended to the end of the file, so in effect the printer file is like an infinite supply of fanfold paper. When a virtual machine is closed the corresponding printer files that are still empty are removed, so the desktop will not be cluttered with empty files.
The easiest and safest way to inspect the printed output is by clicking the "Printer" button in the devices drawer. First, this button places the emulated printer in the "offline" state, so the Apple ][ will hold new output until the printer goes online again. Next, the corresponding output text file is opened in TextEdit. To continue printing, close the text file and press the "Printer" button to put the printer online again.
In the early 80's, a serial connection was an inexpensive, simple, and therefore popular way to connect the Apple II to another computer. This could either be a local computer, directly connected with a serial cable, or a remote computer, accessible via a modem. There was no such thing as the Internet back then, but a network of bulletin board systems (BBS's) existed that allowed their members to log on using a modem (typically 1200 baud, sometimes even slower).
Virtual ][ emulates the Super Serial card (SSC), which was produced by Apple and was the de
facto standard for serial communication on the Apple II. This card implemented the universally
accepted RS-232 standard.
The SSC emulation can be configured
to connect to a real serial connection on your Macintosh. Even though Macs don't come with
a built-in serial port anymore, there are still several ways to use this medium. One option is a
USB-to-serial adapter; another one is a built-in modem; and a third option is Bluetooth. The
Virtual ][ configuration panel presents you with a pop-up menu that contains all
serial devices available on your Mac. Exactly what it shows depends on your hardware configuration,
but here is an example of what it could look like.
In this example, the top three menu items belong to a USB-to-serial adpater; the next two represent a Bluetooth
connection to a mobile phone. The two entries below the separation line are built-in modems.
If you have Bluetooth in your Mac and in your cell phone, you can use an Apple II
communication program to actually talk to it; for example, issuing the command "AT+CGMI" causes
the phone to return its manufacturer's ID.
Configuring the serial communication setup requires some patience, just as with the original Apple II. There are three areas to take into account: the DIP switches on the Super Serial card, the device connected to it, and the Apple II software.
The DIP switches on the SSC control a number of customizable options like the baud rate at power-on. These options can be configured in a separate window, by pressing the "Configure..." button below the picture of the SSC in the main configuration panel.
You cannot manipulate the DIP switches with the mouse; instead you can select options with the
buttons, and you'll see the switches move accordingly.
Note that many of these settings can also be set by the Apple II software, which is actually
more convenient than setting the DIP swiches and restarting the virtual machine.
The options that can not be changed by the Apple II software are communications / printer mode and
interrupt mode. When the latter is selected the SSC triggers an interrupt when data
is sent or received, in order for the Apple II to deal with that event immediately. Only activate
this option if you know the Apple II software supports it!
Note that some of the DIP switches cannot be changed at all; they must have a fixed setting in order for the
emulation to work properly. In particular, Virtual ][ does not support the old Apple serial interface
modes of the SSC.
Note further that switch 8 is a dummy on both banks; it has no function.
The second area to worry about is the Macintosh device connected to the SSC emulation. Note you can select this device and the associated options without the need to restart the virtual machine.
These checkboxes correspond to three special signals the SSC can receive: Data Set Ready,
Data Carrier Detect, and Clear To Send.
These signals all tell something about the status of the connected device. For example,
the DCD signal is generated by a modem when it has a connection,
over a phone line, with another modem. This is a very useful signal for
an Apple II program that waits for an incoming call: when DCD is activated, the program
knows someone made a dial-up connection.
Unfortunately, due to a lack of strict standards, some Apple II programs interpret these signals
in a different way. For example, the firmware of the SSC only sends a character when
it detects that the DCD signal is ON. This effectively prevents the program to send a dial-up command to
a modem! With the original Apple II this was solved by connecting the DCD line
to another line, to ensure it was always ON. This same technique is supported by Virtual ][:
checking a box in the configuration panel sets the corresponding signal to ON.
Also, not all serial devices generate these signals. Usually the Apple II software will
verify the DSR signal, which indicates that the connected device is powered on. However,
when the other device does not generate this signal, or when the line is absent from the serial cable, the
only option is to force the signal to be ON.
The CTS signal is used for hardware handshake and should usually not be forced ON.
More information on these signals can be found in Wikipedia.
The "asynchronous send" option controls a timing aspect. When the option is turned
on (the default), Virtual ][ forwards each outgoing byte to Mac OS X, and immediately allows the
Apple II to send the next byte. Meanwhile, OS X sends these bytes whenever it has the opportunity to
do so, in other words: asynchronously. As a result, there can be some delay between the Apple II sending the byte
and Mac OS X actually delivering it to the device at the other end of the line. Usually this works fine, and
this approach results in a throughput that is almost identical to the original Super Serial card.
However, there are circumstances where the asynchronous approach fails. For example, consider a situation
in which the Apple II sends characters to a printer, and pauses after each "newline" character, in order
to give the printer the opportunity to move the paper. In that case, the asynchronous mode would not work,
because the Apple II must pause after the newline character has been received by the printer
(and not after the character has just been sent by the Apple II program).
The only way to accomplish this, is to use the synchronous mode: the Apple II will not send
the next byte until the current byte has been delivered to the other side.
Note that synchronous mode causes overhead and considerably slows down the output stream.
As a last step of your configuration efforts, the Apple II software must be set up to match
the selected emulated hardware options.
Most applications offer the Super Serial card as one of the standard configuration options.
When you want to use a modem, and the modem you use is not listed in the program's configuration
options, the best guess is to configure it as a "Hayes compatible" modem. Also, choose a
moderate baud rate; 1200 or 2400 baud are speeds typically used in the Apple II days. When
it all works, you can try to increase the speed.
When you have a Super Serial card installed, Virtual ][ shows a status panel in the devices drawer. The panel shows the status of the RS-232 signals, and can be a great help in troubleshooting. The signals are described in this Wikipedia article. When a signal is OFF, it is shown in dark red; when a signal is ON (or "asserted"), it lights up. The signals are presented as seen from the standpoint of the Apple II, so "RD" indicates the Apple II receives data, and "TD" means the Apple II is transmitting data.
The signals on the left are input for the Super Serial card; the signals on the right are output. You can click on the button to get a pop-up menu that gives the same options as the configuration panel: you can force any of the input signals to be ON, and you can select (a)synchronous send mode.
If you are familiar with the RS-232 standard, you might notice that the signal "RI" (Ring Indicator) is missing in the status panel; the Super Serial card does not support it.
The cassette recorder emulation is able to record a file with the sounds produced by the Apple ][ cassette output, and also to read such a file and feed it to the Apple ][ cassette input. Effectively, this provides a fully functional cassette tape emulation. The cassette tape files are actually standard AIFF files. If you are curious how they sound, you can open a cassette tape file in the Quicktime player. Note that you might have to change the file name extension from "cass" to "aif" for Quicktime to recognize the file. It is recommended to turn down the volume a bit, because the sound is loud and ugly.
It is even possible to sample an original Apple ][ cassette tape and read it in the emulator. Refer to "Format of the cassette tape file" for details.
Remember that the main purpose of the cassette tape support is nostalgia. It is much more practical to store data on an emulated disk, because the cassette files can become pretty big and the I/O is time consuming.
To "play" a cassette tape, it is sufficient to "insert" the cassette tape file in the cassette recorder. This can be done in a similar way as inserting a disk in a disk drive: either click the appropriate media button and select a file, or drag the file from the Finder to the cassette recorder icon in the devices drawer. The cassete recorder icon will show a "Play" symbol, but actually the tape starts playing when the first sample is read by the Apple ][ software. So there is no hurry to start the Apple ][ software that reads the tape, even if the tape is inserted first.
You can try this using the "Welcome tape" distributed with the program. It contains a simple Applesoft program. First make sure you see the Applesoft prompt ("]"), then type "LOAD" and press return. Now insert the tape as described. Reading the tape takes about 30 seconds. When the prompt shows up again you can type "RUN" to run the program just loaded.
To eject the cassette tape click the cassette recorder icon.
It is not possible to overwrite an existing tape file. To make a recording, create a new tape by clicking the "New cassette tape" icon in the devices drawer and specify the name of the tape in the file save panel that appears. The cassette tape icon shows a "Recording" symbol, and recording starts right away, so the first few seconds of the recording are probably silence. Note however that after the Apple ][ software has produced the last sound sample, no more silence is recorded, so there is no rush to remove the tape after recording has finished; the file won't grow more than necessary.
If you want to try sampling an actual Apple II cassette tape, you'll need to know the exact file format:
When reading such a sample in the virtual machine, you might end up with "ERR" displayed on the screen. If this happens, the emulated software did detect a signal (which is good), but was not able to read all data. In this case, try a few different settings for the playback volume slider. You'll find it in the "Cassette interface" section of the configuration panel.
Note that the entire file is kept in memory as long as the cassette tape is in use.
Note this chapter is only applicable to the Apple ][(+). For the Apple //e, see "Using 80-column display on the Apple //e ".
The Virtual ][ emulator has the option to present 80-column text video by inserting an emulated 80-column card in slot 3. Note that the card does not work in any other slot! The 80-column card contains its own video generator circuitry, and is connected to the video monitor through a "video soft switch". This switch has two inputs, and one output. The internal video generator and the 80-column card are connected to the inputs, and the switch forwards one of the signals to the video monitor. It looks at the state of annunciator #0 to determine which signal to forward. A reference to address $C058 selects the primary input signal, and $C059 selects the secondary input signal. Furthermore, Virtual ][ contains configuration options to choose which video generator is primary and which is secondary. The next picture summarizes the different options:
In the picture, "Show Built-in" and "Show 80-col." refer to choices in the "Quick settings" menu.
As the 80-column card is in slot 3, "PR#3" will shift input and output to the card. Or when you start the UCSD Pascal system, it determines the card automatically and switches I/O to it. In all cases it is still necessary to direct the 80-coumn video output to the monitor as described above.
The 80-column card supports the full ASCII character set (upercase
and lowercase). In order to work correctly, the "shift key
modification" must be applied. You'll find this setting under the
keyboard configuration. The "shift key modification" in the original
Apple ][ involved connecting pin 2 of the keyboard
encoder board to push button 2 (pin 4) of the game I/O connector.
This modification allowed the software on the 80-column card to
detect whether the shift key was pressed in combination with any of
the other keys.
Note that in order to enter lower case letters, "Soft Caps Lock" must
be turned off in the "Quick settings" menu.
When the keyboard is correctly configured for use with the 80-column card, all characters can be entered in the normal way, except two: when you enter "^", the 80-column card translates it to "N". Likewise, it translates "@" to "P". This is a result of the original Apple ][ keyboard layout. These two characters must be entered with the "ctrl" key pressed.
Also, the 80-column card has a few interesting special key
combinations. The below table summarizes all special key
combinations.
|
ctrl-shift-^ |
Enter the character "^" |
|
ctrl-shift-@ |
Enter the character "@" |
|
ctrl-shift-E |
Inverse mode |
|
ctrl-shift-C |
Normal (non-inverse) mode |
|
ctrl-shift-D |
Make hardcopy of the screen on the emulated printer. |
|
ctrl-shift-A |
Toggles the soft caps lock of the 80-column card. This is basically the same as the soft caps lock of the emulated keyboard (command-shift-A). You can use either option to enter lower case characters. |
The Apple //e has built-in 80-column software support. The only additional thing needed is a memory card in the auxiliary slot. By default, such a card is present in a newly configured virtual Apple //e. It allows 80-column display, double-hires, and adds 64K of memory to the machine, bringing the total amount of memory to 128K. Note that this card can be configured to contain more memory (up to 8MB).
The Apple //e contains only one video generator, which is used to produce either a 40-column display or an 80-column display, so no "video switcher" component is used, like in the Apple ][.
Virtual ][ emulates the
AppleMouse // card. This allows you to run programs like
MousePaint or GEOS.
Apple II software that uses the mouse must switch it
"on" in order to become active. When this happens, the Macintosh
mouse pointer is hidden, and replaced by whatever mouse pointer the
Apple II software provides.
The mouse emulation is designed to smoothly integrate with the Macintosh mouse: when the mouse pointer enters the window, it instantly turns into the Apple II mouse, and the Macintosh mouse pointer is hidden. The reverse happens when the mouse moves out of the window: in that case it becomes a Macintosh mouse pointer again.
Unfortunately, integration with the Macintosh mouse is not compatible with some Apple II programs. It is compatible, for example, with MousePaint, but it doesn't work wel with GEOS. To solve this problem, the mouse emulation supports a special mode of operation: "relative mouse mode". You'll find it in the "Quick settings" menu. When this mode is switched on, programs like GEOS work well, at the expense of Macintosh mouse integration. Once the mouse has entered the window, it will be captured there, and you must hold down the command key to let it escape.
The Apple ][ was not equipped with a built-in real time clock. Several extensions existed to provide a clock, and Virtual ][ emulates three of them.
The emulated clocks take the current time and date from the Macintosh clock. Only the Thunderclock emulation allows adjusting the date and time; the others do not. However, when you reboot the virtual machine, or create a new one, the Thunderclock will always be reset to the Macintosh system clock. Changing the Thunderclock time does not affect the Macintosh clock.
A popular enhancement for the
Apple ][ (and //e) computers was the Z80 card. This card
contains a Zilog Z80 or Z80A processor, plus hardware to transfer the
flow of control from the main 6502 processor to the Z80 and vice
versa (only one of the processors can be active at any time). The Z80
card made it possible to run the CP/M operating system, and gave
access to popular applications like Wordstar, DBase and Supercalc. It
also allowed the use of programming languages like Turbo Pascal,
Fortran, and even COBOL.
The Z80 card in Virtual ][ emulates the Z80A processor.
You can configure the processor to run at a speed of either 2 MHz or
4 MHz.
To use the card you need a bootable Apple ][ CP/M disk
image. The boot software on this disk searches for the presence of a
Z80 card. When it detects one, it switches to the Z80A processor.
After booting is complete, the CP/M prompt is presented.
The original Apple ][ came with
two game paddles. Each paddle provided an "analog" input by turning a
knob, and a "one-bit" input by pushing and releasing a button. A
popular enhancement was to replace the two paddles by one
joystick.
The Game I/O connector of the Apple ][ allows for
connecting 4 analog inputs and 3 one-bit inputs. All of these can be
emulated by Virtual ][, either with the Macintosh mouse
and keyboard or with a game pad / joystick
connected to a USB port. Virtual ][ will always use
the USB game controller when it detects one.
The program automatically selects this method when it detects a suitable game controller connected to a USB port. You can specify the mapping between buttons on your game device and the Apple ][ game inputs by selecting "Configure Game Controller" from the "Virtual ][" menu. In the dialog that appears you can select a game device button or slider and link it to a corresponding Apple ][ input, such as "Paddle Analog #0", or "Paddle Button #1".
The dialog will probably appear in the non-graphical mode (as
shown on the right), unless you happen to have a Wingman Rumblepad,
in which case a picture of the device is presented (as shown on the
left).
Two special actions can be assigned to buttons on the game device:
"Pause / Resume" and "Pause and Configure". The first one pauses the
entire virtual machine, and therefore is useful to temporarily
suspend game play. Pressing the same button resumes the game. The
second option pauses the virtual machine and shows the game
controller configuration panel. This is useful when you want to try
different settings for a specific game.
Note that the game controller mappings are part of the overall
configuration of Virtual ][, not just of one specific
virtual machine configuration. The game controller settings are
automatically saved.
Virtual ][ lets you control the game paddles with the keyboard as well. In the configuration of the game connector, you can activate the arrow keys to be used as a joystick. This works fine for many games, but be aware that it does not give you the same amount of control as a real joystick does. A real joystick produces values between 0 and 255 for the horiontal and vertical directions. With the keyboard arrows, the possible values are limited to only three: 0, 128, and 255.
You'll find the "Game connector" configuration panel in the "Built-in connections" section of the machine configuration.
Technically speaking, the left / right arrow keys control game paddle number 0, and the
up / down keys control paddle number 1. When you notice that pressing the "up" arrow
actually moves your game character down, click the "Flip vertical motion" checkbox.
The emulated joystick is self-centering; when you release the arrow keys the joystick position
goes back to the center.
As a shortcut to activate the arrow keys, you can also select "Use Arrows as Joystick" from the "Quick settings" menu.
The push buttons on the paddles can be controlled by the mouse buttons or the keyboard modifier keys:
control, alt and command. It is recommended to assign the control key to push button 0, and
to avoid the use of the command key during game play.
Note that push button #2 is not available if it is being used in the
"shift key modification", required for the Apple ][(+)
80-column card.
As a third option, you can use the mouse to control the analog game paddle values. However, because Virtual ][ cannot detect mouse movements outside its window, this feature works only when the program runs in full-screen mode. Furthermore, it is disabled when a USB game pad or joystick is connected.
This mode of operation is automatically selected when Virtual ][
doesn't detect a suitable USB game controller.
The analog values depend on the position of the mouse on the (main) screen.
Note that when an Apple II mouse card is inserted and switched
on, the Macintosh mouse only feeds the emulated Apple II mouse,
not the game paddles.
The push buttons can be controlled with either the mouse buttons or the keyboard modifier keys, as explained in the previous section.
The internal speaker is the device that produces the "beep" sound when you switch on an Apple ][. In the emulator, you'll hear the sound on the Macintosh loudspeaker (or external speakers if you installed them). The original machine had no way to control the sound volume or to switch off the sound. However, the emulator does. In the toolbar you'll find a control for it.
The size of the main window can be adjusted with the "Screen" menu. You can choose single size, 1.5 size, or if your Macintosh display allows it, double size. By default Virtual ][ presents the screen in single size, but you can change this behavior with the "View" section of the application preferences.
Full-screen mode makes the emulation even more realistic. In full-screen mode the screen of the frontmost virtual Apple ][ is presented on the main (or only) Macintosh display. You can easily switch between window-mode and full-screen mode with the key combination "command-enter".
As an option, the program can adjust the resolution of your Macintosh screen in full-screen mode, so that it closely matches the resolution of the Apple ][ screen. This has the advantage of improving performance, in particular on big screens. If your machine can handle the load, it is recommended to leave the screen resolution as it was; the rendered image will look much better.
In full-screen mode it is not possible to operate the buttons in the devices drawer or switch between different virtual machines.
In full-screen mode on an
Apple ][(+) you can use all keyboard shortcuts in the
"Quick settings" menu, which includes switching between color and
monochrome, and switching between 40-column and 80-column display.
You can also use command-I to insert a new diskette: the emulator
temporarily switches to window-mode and switches back to full-screen
after a disk image has been selected.
However, when in full-screen mode on an Apple //e, the command
key is used as "Open Apple" key. Macintosh keyboard shortcuts won't
work, except for command-enter to go back to window-mode.
Virtual ][ lets you easily record a QuickTime movie of everything that happens on the emulated Apple II screen. Just select "Make Movie of Apple II Screen" from the File menu. The program will present a standard File Save panel to let you select where the movie must be saved. After that, recording starts, and will continue until you select "Stop Movie Recording" from the File menu. After recording has stopped, the movie will automatically be opened in the QuickTime movie player.
If you pause the virtual machine, movie recording also pauses. It continues when you resume the virtual machine.
During recording, the movie is written to a temporary file on your disk. When you stop recording, the temporary file is moved to the location you selected. This might take a few seconds.
Virtual ][ records the movies at 20 frames per second. To do this alongside the running emulator requires a lot of CPU power. However, a modern Intel-based Macintosh can handle this. On an older machine, such as a PowerMac G4, you might notice a decreased frame rate.
The movies recorded in Virtual ][ typically take 3 to 6 MB of disk space per minute. If you want, you can reduce the file size later on, by opening the movie in the QuickTime player, and exporting it with a high compression codec such as H.264. This may take a while, but can reduce the size of the movie considerably.
Note that the movie recording option is only available in the full license version of the program.
The computer's "character set" is the collection of all characters that can be displayed on
the text screen. The US
model of the Apple II computer was equipped with the
standard ASCII characters, but
international models usually had an alternative character set, with characters
for specific languages. For example, the French model supported characters like
à, é, and ç. Because the character coding space was limited,
these characters replaced @, {, and \, respectively.
The international Apple II machines came with a switch that allowed the user to
instantly switch between character sets. The same functionality is available in
Virtual ][. The "Quick settings" pull-down menu contains a list of available
character sets.
By selecting a character set, some of the characters on the screen immediately change. This example shows how the Apple //e welcome line is shown in the Latin character set and the Greek character set, respectively.
International Apple II computers came with a keyboard that supported the
special characters that were available in their character set. On a French keyboard you could press the
key labeled é, and if the French character set was selected, an é would
actually appear on the screen.
Modern international Macintosh keyboards look very much like the international
Apple II keyboards. Virtual ][ supports these keyboards by translating
characters such as é to the equivalent Apple II code. Each character set comes
with an associated translation table, which is activated automatically when you select a character set.
So for example, if you have a French Macintosh, and you set Virtual ][ to the French
character set, pressing the key labeled é on your keyboard will also produce an é on the screen.
However, if you select the "Latin" character set (the standard ASCII characters), pressing the same key
will not produce a character, because no French translation is in effect.
Because the keyboard behavior obviously depends on the currently selected character set, you'll see
a little flag symbol at the bottom left of the window to remind you what the current setting is.
The program comes with a number of predefined character sets, as shown above. The character sets "Latin" and "Latin Uppercase Only" are the ones representing the standard ASCII characters. The "uppercase only" variant was used in the Apple ][ and the Apple ][+, because these machines lacked lowercase character support. The "Latin" set was standard in the Apple //e, and contains all ASCII characters plus a number of special characters (the so called "mouse characters", used to draw user interface elements such as window borders).
In the Apple II computer the characters were defined in a character generator ROM, which could be replaced by a customized ROM. Virtual ][ offers the same feature. In order to do this, you must provide the program with the following:
The character definition bitmap should be placed in the directory ~/Library/Application Support/Virtual ][/CharacterSets. The file contains pictures of all symbols in the character set, and must be structured as follows:
The second element of your own character set, the "flag" symbol representing the character set, can be any picture format Mac OS X is able to read. It is recommended to use the tiff or png format. For best results, make the picture at most 11 pixels high and at most 16 pixels wide. The picture must be stored in the same directory as the character set definition file.
The individual files, along with the keyboard translation table, are tied together in an
XML file with this path: ~/Library/Application Support/Virtual ][/CharacterSets/International.plist.
It is recommended to create such a file with the "Property List Editor" program. It's format can
best be explained by showing an example.
This example contains two custom character defintions, named "My character set" and "Yet another character set".
These names will appear in the Character Set menu. If you choose a name already in use by a built-in set, your definition
replaces the built-in one. So if you want to add a new character set, be sure to choose a unique name.
Each character set entry is itself a dictionary with three elements: the name of
of the character set definition file, the name of the associated icon file (the "flag" symbol), and the
keyboard translation table. You can leave the icon file name empty if you don't want to assign one.
The keyboard translation table contains two columns: the first is the character typed on the Macintosh
keyboard; the second is the resulting ASCII code (in the range 0 - 127) that will be input in the virtual
machine. You can specify the second column value as either a number (the ASCII value) or as a string
(the actual character). The first column must be one single character, and it must not be in the standard
ASCII range. So for example, you cannot translate the character "a" to something else, nor can you translate a
control code or a function key. You can, however, translate non-ASCII characters, as shown in the example.
Virtual ][ has many configurable options. Different virtual machines can have different configurations. The configuration can be saved using the "Save Configuration" choice of the File menu. Use the "Open..." choice of the File menu to create a virtual machine from a saved configuration (or simply double-click a configuration file in the Finder).
To change the configuration of a virtual machine, choose "Configure..." from the Machine menu, or click the "Setup" button in the toolbar. The configuration of the current machine is presented in a sheet, like this:
The configurable options are presented in the left pane, in a hierarchical way. When you click on a configurable item, the right pane shows that item's configuration options. You can change one or more configuration options and then press "OK" to change the configuration of the virtual machine. Some changes can be made without restarting the machine (like changing the monitor from monochrome to color); other changes require a restart. If you make a change that requires a restart, a warning is shown at the bottom of the configuration sheet. Note that if you want to save the modified configuration, you have to choose "Save Configuration" from the File menu. Virtual ][ will remind you if you close the window without saving.
Some of the configurations can also be changed with the "Quick settings" menu. It deals with properties of the monitor and keyboard, and provides an quick way to change them. The changes made with this menu don't mark the configuration as "changed", so if you close the window you will not be reminded to save the document. However, if you save the document, the current quick configuration settings will be saved with the configuration.
To see if the virtual machine runs fast enough on your Macintosh, choose "Show Performance" from the Machine menu, or click the "Speed" button in the toolbar. It reveals a drawer with performance statistics, like this:
The presented minimum, maximum and average
CPU statistics are measured starting at the moment the drawer opened,
and are relative to the nominal CPU speed. So if "average" is 100%,
the virtual machine runs exactly at the intended speed.
"Current" is the speed (in MHz) of the currently active processor.
When the internal 6502 (or 65C02) is active, the number is presented
on a red background; an orange background means the Z80A processor is
currently active. This speed is also represented by the red / orange
line in the graph. The yellow number and yellow line represent the
number of screen refresh cycles per second.
Wen the CPU speed drops below the nominal speed, the program tries to
compensate the speed, in order to end up with an average of 100%.
However, if the video refresh rate drops too low it is not
compensated (as this would be a waste of processing power).
Note that when you are running CP/M (and thus using the Z80A
processor), you will still see a lot of 6502 activity in the
performance monitor. This is caused by the fact that the CP/M BIOS is
implemented by 6502 functions (in the Apple ROM, for example). So all
I/O is handled by the 6502.
Virtual ][ supports Apple's powerful AppleScript technology, which allows
you to control the virtual machine using a script. The script can do such things as create and configure
virtual machines, type commands on the virtual keyboard, wait until the screen indicates an operation
has finished, save printed output, and even insert
disk images directly from the Internet. It allows you to let Virtual ][
perform an automated task, such as starting up your favorite Apple II game.
You can also use it to create some nice Apple II demo's.
The program comes with a number of example scripts, which you can find in the AppleScript
menu.
When you select one of the example scripts from the menu, you will get the choice to either run the script or open it in the Script Editor. The scripts are hidden inside the Virtual ][ application bundle, so if you want to make changes, it is recommended to save them in a different location.
When you make your own scripts, you can add them to the AppleScript menu by copying them to the Virtual ][ scripts folder. The easiest way to locate that folder is to select "Open Scripts Folder" from the AppleScript menu.
This example shows some of Applescript's possibilities.
Suppose you often play the game "Little brick out", which was distributed on the original DOS 3.3
master diskette. You always play it on an Apple ][+ with a color screen.
When you make a script that starts your favorite game in Virtual ][, you only have to double-click
that script to begin your game play.
In its most elementary form this is what such a script looks like.
The script assumes that the disk is called "3.3 master.dsk", and is in the folder you configured
as your "favorite disk folder" in the Virtual ][ preferences.
The script first moves Virtual ][ to the foreground (activate) and
gets rid of any currently running virtual machines. It then
creates an Apple ][+ and makes sure it has a color screen. After that, it inserts the
disk image into slot 6, drive 1. While the machine boots, the script types the DOS command to run
the game: "RUN LITTLE BRICK OUT". Virtual ][ sees to it that the typed characters are buffered
until the Apple ][+ is ready to process them (which is after booting is complete).
Although this script works OK, it can be improved by temporarily switching the virtual machine to a higher speed during booting and loading the game. This dramatically reduces the start-up time; from the almost 30 seconds it takes on a real Apple ][, to only a few seconds (depending on your type of Macintosh).
The trick is that the script sets the speed of the virtual machine to "maximum", and resets it to "regular" after the game finished loading. The latter is important: you don't want to play the game at top speed! The script must know when to reset the speed; it does this by looking at the screen with intervals of 0.5 seconds. When the last line on the screen displays "PRESS THE SPACE BAR TO BEGIN....", we know the game has started and the speed can be reset.
When you want to write a script, a good start is to study the example scripts.
Virtual ][ does not support recording a script in the Script Editor, so you'll
have to use the editor to type the statements yourself.
However, if you are familiar with the AppleScript language you'll find it easy to write scripts
for Virtual ][. The script dictionary is based on a simple object model.
At the top of the object hierarchy is the application object, as in any AppleScript
dictionary. The application contains one or more machines. When you make a new machine
object, you'll get a machine that is configured like the default configuration, just as when you
select "New Default Machine" from the File menu. Another way to create a machine object is
by making an instance of one of the classes AppleII, AppleIIPlus or AppleIIe.
The third way to make a machine is by opening a saved configuration file. You'll find examples of
these techniques in the demo scripts.
Referring to a specific machine occurs just like referring to a document in other AppleScript-aware programs: by number or by name. When you have just one virtual machine running, the easiest way is to just say front machine.
A machine object contains a number of devices. You cannot create these device objects with AppleScript; they are automatically created when you create a machine. You refer to the devices by name. For slot devices, the name is derived from the slot it is connected to. For example, a device connected to a card in slot #1 is called "S1". A disk drive, typically connected to a disk card in slot #6, is called either "S6D1" or "S6D2", depending on whether it uses connection 1 or 2 of the disk card. If you are familiar with Applesoft Basic, these device names should look familiar. Devices that are not connected to a slot have fixed names. For example, the cassette recorder device is simply called "cassette recorder".
To find out the device names currently in a machine, execute a script as shown in the example below.
Each device has a property, devicetype, which indicates what it is: an Epson printer, a hard disk, and so on. This example shows the device types of the same virtual machine as the previous example.
You can find out what is on the machine's screen by using the property screen text or screen picture. The screen text gives a collection of all the lines on the screen. You can examine these text objects to see if the running process has produced screen output. Often it is more convenient to use the alternative compact screen text; this one omits empty lines and strips trailing space characters from the remaining lines. Study the example scripts to see how this can be used.
The screen picture property can be used in the same picture command. This powerful command compares (part of) the screen picture with a previously saved file. This allows you to wait until a running process has rendered a specific picture on the graphics screen. Virtual ][ offers a convenient way to save the pictures to compare to: use "Export Screen Picture" in the File menu.
Waiting for some screen output to appear is typically a combination of two things: testing the condition and using the command delay. The latter is part of the standard AppleScript additions. It suspends script execution for a specified time period, while the virtual machine keeps running. This allows you to test the screen at regular intervals (every second or so). The example scripts demonstrate this technique.
Finally, the dictionary supports a way to enter any key on the Apple keyboard with the type command. It has a number of variants, so apart from typing plain characters, you can also enter control-key combinations, open and solid Apple keys, and other special keys like up and down arrows. If the AppleScript type commands are executed faster than the Apple II can process them (which is very likely) the keystrokes are buffered until the Apple II processes them. So eventually all keystrokes will arrive in the virtual machine and none will get lost.
To find out the details of using AppleScript with Virtual ][, use the Script Editor to open the application's dictionary and study the classes, commands and properties.
Did you encounter technical problems in Virtual ][? Or perhaps you found an Apple II program that doesn't run, or have suggestions for improvements? Tell me about it by e-mail. When reporting a problem, don't forget to mention what versions of OS X and Virtual ][ you use.
You might also want to check if a newer version of Virtual ][ is available on the download page.
My intention is to make Virtual ][ the most complete and versatile Apple ][ emulator on the Macintosh platform (or on any platform, actually). If you have ideas for improvements, please let me know by e-mail.
This is a bug-fix release.
Many of the enhancements are the direct result of feedback I received from users. Thanks every-one!
This release adds much-requested features and a number of other improvements.
This release contains numerous new features and improvements.
Initial release
Not all Apple ][ hardware features are supported, and some things work slightly different.
I bought my first computer, an Apple ][ europlus, in early 1982. It had 48 KB of RAM, a monochrome green monitor, and one Disk ][ drive. It cost me an arm and a leg, but I never regretted the purchase. On the contrary, during the years I used the machine, from 1982 to 1986, it gave me enormous amounts of fun, and in the end it was worth every penny I paid for it. During that period, I purchased more and more add-on peripheral cards, like the 16K RAM card, a Z80 card, an 80-column card, a clock card, a printer card, a super serial card, and a PAL TV card (which allowed me to finally see the colors the Apple ][ produced, on a TV screen). I found lots of enjoyment in writing programs for the Apple ][, and in discovering exactly how everything worked. I did quite a bit of reverse engineering myself, and bought several technical books (see Acknowledgements). In 1986 I bought my first Macintosh, and soon the Apple ][ was moved to the basement. Ten years later, around 1996, I found that a number of very good Apple ][ emulators were available, like Stop The Madness (STM) and Catakig. One weekend, I got the Apple ][ from the basement, set it up on my desk, and to my surprise everything still worked without a problem. I connected the Apple ][ to the Macintosh with a serial cable, and created software on both machines to convert my many floppy disks to disk images on the Macintosh. Again to my surprise, all disks could be read without a problem despite their 10 year stay in the basement. In the end, I managed to convert all my disks, even the "copy protected" ones, like Bag of Tricks and Visicalc.
The purpose of this was just to enjoy the nostalgia and relive the magical early days of the home computer era. When I switched to Mac OS X in early 2002, I regretted that none of my favorite Apple ][ emulators were available in the new OS. Early 2003, I decided to try and write my own Apple ][ emulator. It seemed like a challenging and fun project, and so far it still is.
The 21-year old Apple ][ again played an important role in the realization of the Virtual ][ application; I used it for almost all of the photographs in the program, and to compare the behavior of the emulator with "the real thing".
Quick progress on the project was made possible by a few excellent books I purchased many years ago.
The "Apple ][ Reference Manual" came with the machine,
and contains an accurate and detailed description of all built-in
hardware elements. It formed the basis of the class design of the
core library.
"Beneath Apple DOS" by Don Worth and Pieter Lechner was essential for
the implementation of the disk drive emulation. To my knowledge it is
the only book that describes the nibble encoding scheme used to store
data on disk.
"Programming the 6502" by Rodnay Zaks has always been my reference to
the 6502 instruction set.
"What's where in the Apple?" by William F. Luebbert was very helpful
during troubleshooting and as a quick reference to the
Apple ][ I/O addresses.