Philips P800 progress...

Hi Everyone, I'm making some good progress with the Philips P800 minicomputers. I'm anxious to get an operating system running on them, and lack of working disk drives (I haven't been able to get one of the X1215 cartridge disc drives going yet), has pushed me in a somewhat different direction. I found an image of an X1215 disk pack containing a DOS version 5 installation on Theo Engel's website. I have implemented a very basic X1215 emulator in an FPGA PCIe card. Together with a small piece of software, and a cable with the necessary level converters, the emulator presents the X1215 disk images to the disk controller in the P800. The software is responsible for loading the image into the FPGA's memory buffer one track at a time. This now works to the point where the initial part of the IPL works correctly. Four sectors are read from disk, after which the P800 displays a "MONITOR?" prompt. After typing "DOM", there is another flurry of disk activity, then nothing. No "** DOS 05 **" banner. I noticed that the disk emulator never asks for anything other than track 0, so there is probably an error in the implementation of the SEEK command. To be continued...