COMBOARD (MC68000) hardware hacking (was Re: Solderless breadboarding) - test-drb@ccmp.vtda.org

18 Feb 2010

On 2/18/10, Henk Gooijen <henk.gooijen at hotmail.com> wrote:
...
  I have no experience with SCSI chips... 
No harder to wire up than a UART or PIA/VIA, but the rest is all
software to create/interpret the SCSI packets.

...
  but the software to read and write a sector of an IDE
disk is simple enough. 
I've written low-level driver code for IDE manipulation on a GG2 Bus+
equipped Amiga.

...
  A TTL-based interface would
 take not much time. 16 bit data (may need buffering) and a few address
 decoding gates is probably all you need to hook up an IDE drive. 
Address decoding gates might not even be required - I have full
schematics for this board (I used to make them commercially) and have
the PAL equations for the memory map PALs.

I think it could be as easy as buffers and a PAL swap (plus software).
 I just flip-flop between SCSI and IDE and never get started.

-ethan