A2CLOUD: use disk images

Once you’ve downloaded stuff to your Pi, or copied stuff on to it from another computer on your network, you can immediately use the vsd1 or vsd2 commands for an uncompressed disk image file (.DSK, .DO, .PO, .RAW, .HDV, .2MG. ISO) containing ProDOS files, and then access them from your Apple II. The image file will be “inserted” into virtual drive 1 or 2, and accessible from VSDRIVE at S2,D1 or S2,D2.

If what you download is an archive file (.SHK, .SDK, .BXY, .ZIP, .TAR.GZ, etc.), you’ll need to expand it first, which you can read about how to do in the next post.

If you’re not sure whether the disk image you downloaded is ProDOS format or not, you can type a2cat imageFileName on your Pi, and it will catalog the disk and tell you the format at the bottom of the listing.

If it’s a DOS 3.3 disk, you can type dos2pro imageFileName to copy the files to a new ProDOS  image, or dos2pro imageFileName DOSFILENAME to copy a single file. Some programs may not work when copied to ProDOS.

Or, you can use ADTPro to transfer the image file to a floppy disk. To make a disk image available to ADTPro, you need to move it into into the ADTPro disk images directory (/usr/local/adtpro/disks) by typing forfloppy imageFileName. To access the files inside that directory, you can also refer to it as $ADTDISKS (e.g. ls $ADTDISKS).

You can also use vsd1 or vsd2 for non-ProDOS disks, but you won’t be able to access them from within ProDOS. However, you can use a ProDOS utility which knows how to access the format (e.g. System Utilities can copy files from DOS 3.3 and Pascal disks).


Some commands for working with Apple II disk images:

mkpo -b totalBlocks newImageFileName PRODOS.VOL.NAME will make a new disk image that has the capacity specified in totalBlocks. (A block is 512 bytes, or half a KB.) The maximum block count is 65535, though if you plan to use the disk image with VSDRIVE, a realistic maximum is 8192. If you omit -b totalBlocks, you’ll get an 800K disk image, unless your image name ends in “.dsk”, in which case you’ll get a 140K disk image. You can also omit PRODOS.VOL.NAME to get an untitled disk image.

dopo imageFileName will convert a DOS-ordered 140K disk image to a ProDOS-ordered image, or vice-versa. The original ordering will not be kept.

acmd will do lots of stuff with Apple II disk images (many formats, including ProDOS, DOS 3.3, and Pascal, are supported). Type acmd by itself to see usage; syntax for copying files in and out of images will be mentioned in the next post on transferring things to your Apple II. (cppo is an alternative, but it’s even slower. It does preserve dates, however.)

$VSD1 and $VSD2 can be used in commands to refer to the disk images assigned to virtual drives 1 and 2, rather than typing out the full path.

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