LispOS on a 68000
Thu, 14 May 1998 16:46:21 -0500
>>>>> Mike McDonald <email@example.com> writes:
> Wow! I haven't heard of anyone trying to hack a homebrewed
> system in years! Everyone seems to just buy an already built
> motherboard (most likely, a PC one) and then hack
> software. Sounds like fun. (Really sounds like things from my
> past. Say fifteens years ago! Anyone remeber a thing called the
> "Big Board"?) Are you building your own MB to learn how or
I never used a big board, I did have a brief love affair
with CP/M in my teens. No, I'm not building one to learn
how, I already know how (or did). Of course, that was back
when the 6809 was hot. At the moment I am sick of the constant
MHz race in processors and would like an architecture that
does the Right Thing.
> The 68030 would probably be nicer because of the MMU. Having
> a MMU under your control can be useful for things like garbage
I also noticed that there is a public domain 68030 mother
board design floating around. You can apparently buy the
blank boards. However, I would have no qualms about running
the photoplots through a board house. This board is designed
to be compatible with ISA cards, an interesting feature (bug
as I see it).
On the down side, Motorola has issued a End of Life statement
for the normal 68030. The 68EC030 continues to be supported
but lacks the MMU (why?). I haven't checked the other variants
for MMU suport. Of course, you could tack on a 68332 MMU unit...
>> Thoughts? Has this road been covered before? I would probably
>> just communicate with it by way of serial at first; a nice
>> bitmapped display wouldn't be too hard though.
> Oh, we've yacked about the same type of thing for over a year
> now and some 2000+ messages! :-) We've been assuming the use of
> a standard PC as the machine though. Everything else has been
> an endless argument.
Yes, I remember some of the circular discussions on the list.
Something this hardware-centric may be a bit off-topic for
the LispOS list. If anyone wants to discuss it further, I
would be glad to discuss it here, or I can start a lisp-hardware
I think my goals would be:
a. Have *one* variant of video board.
b. Have *one* variant of I/O board.
c. Use standard SIMMs.
d. Use SCSI as much as possible.
I realize that using a 40 MHz processor may seem like a giant
step back. The problem is, newer, faster processors are just
to finicky to diddle with on a one off basis. Otherwise I would
be looking at the PowerPC or an Alpha.