I'm trying to create a boot disk for the Kaypro II (from scratch). I've been using cpmtools to generate file system images for other platforms, mostly with success.

However, the Kaypro II has this weird boot track format where the boot image is on track 0 and the top half of track 1... with the directory in the bottom half of track 1. So the directory ends up sandwiched in between the two halves of the boot image.

Reference: http://bitsavers.informatik.uni-stuttgart.de/pdf/kaypro/Kaypro_II_Dealer_Reference_Manual_1982.pdf

The kpii definition in the standard cpmtools diskdefs file doesn't know about this, so it places files in the top half of track 1. The actual BIOS itself presumably handles this by setting additional bits in the allocation vector while leaving the number of directory entries at 64.

However, I can't figure out how to teach cpmtools about this. The diskdefs file is completely undocumented and the source is obscure. Does anyone know if cpmtools supports this, and if so, how?

  • This Vintage Computer Forum entry seems to talk about using a package called IMD to create a KAYSYSTM.RAW file that they then use with cpmtools ... no idea if that will help? – TripeHound Jun 10 '19 at 9:10

If the boot image needs to occupy areas of the disk which are also addressable as filesystem blocks (which is my understanding of the question above) wouldn't it be simplest to create a file containing the correct data and copy that to the disk first? That would populate the sectors with the required boot image and prevent other files from overwriting them.

If the Kaypro BIOS requires those sectors not to be marked as in use, then I'd expect that could be accomplished by deleting the 'boot image' file once all other files have been copied onto the disk.

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