CP/M on the DE1 FPGA card

2 posts in thread

• juhasz · Msg 747 · inlagg

  2014-06-02 07:13

  Ärende: CP/M on the DE1 FPGA card

  very nice indeed! how close to (what we know of) the myab bios/card is your implementation? robert Skickat från min Samsung Mobil <div>-------- Originalmeddelande --------</div><div>Från: "H. Peter Anvin" <hpa at zytor.com> </div><div>Datum:2014-06-02 00:54 (GMT+01:00) </div><div>Till: abc80 at abc80.org </div><div>Rubrik: Re: [abc80] CP/M on the DE1 FPGA card </div><div> </div>On 06/01/2014 03:53 PM, H. Peter Anvin wrote: Argh... the mailing list stripped the attachment: http://www.abc80.org/~hpa/fpga/abccpm.jpg -hpa http://www.abc80.org/mailman/listinfo/abc80
  • H. Peter Anvin · Msg 748 · kommentar

    2014-06-02 17:37

    Ärende: CP/M on the DE1 FPGA card

    Not very. I actually have the source code to the MyAB BIOS, but I don't know the exact details of their hardware. I decided instead to emulate Mikrodatorn's 64K modification (which I already had implemented) hardware-wise. The other thing was I decided to do deblocking in the disk controller firmware rather than in the BIOS. This was simply a matter of convenience because I *already* have to do deblocking from 512-byte SD sectors to 256-byte ABC sectors, and then having an additional deblocking step to 128-byte CP/M sectors felt rather stupid. So I just extended the disk controller deblocking support to support 128-byte CP/M sectors as an alternative to 256-byte ABC sectors. Yes, it is a bit of a cheat. -hpa