68k homebuilts

[bfranchuk at jetnet.ab.ca]

Ethan Dicks wrote:
> A simple design with a real 68K processor isn't that hard to whip up
> or debug - in fact not much harder than a simple 6502 or Z80 system.
> SRAM, of course, is simpler to implement than DRAM, but DRAM can be
> easier to expand over a couple of MB (for 1MB or less, I'd stuff in a
> couple of JEDEC RAM sockets for a 16-bit RAM field).  Let me amend
> "simple" - simple is peripheral chips and memory that can keep up with
> the cycle time of your processor so that you don't have to handle
> wait-states, etc., and can therefore tie DTACK to ground (as advocated
> by a famous newsletter, "DTACK Grounded".  At 4MHz to 8Mhz, it
> shouldn't be a problem these days unless you have a particular VLSI
> chip you want to use for I/O (6821, 6522, etc.) and it isn't fast
> enough.  ROM and RAM that are fast enough shouldn't be an issue, even
> with inexpensive parts.
>
>   
Was not that newsletter for a APPLE II, co-processor board?
Did anybody ever use one, or any kind of general purpose co-processor
boards for the PC?
> -ethan