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RE: [N8VEM-S100:614] Re: S-100 68K CPU board status
That?s great on the 68K board Andrew. I'm running into some real headwinds
with the VGA board. Already extensive mods on the prototype and I'm still
not even accessing the EEPROMS! There are some strange things going on with
16 bit word access on odd/even addresses. So when the 68K and MSDOS support
boards are optimized I may be ready for a break to something different.
I was kind of hoping somebody here could take up the challenge of getting a
basic CPM68K going with our IDE board and Console I/O board using the
CompuPro BIOS. Should not be too difficult. That way I can concentrate on
hardware. My goal for next year will be to have 32 bit Intel & Motorola CPU
chips on the S-100 bus. It's going to need a lot of hardware time (and
John Monahan Ph.D
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On
Behalf Of lynchaj
Sent: Wednesday, December 28, 2011 4:04 AM
Subject: [N8VEM-S100:614] Re: S-100 68K CPU board status
Hi John! Thanks! Wonderful news!
Yes, the CompuPro documentation is excellent as is the DRI material.
It seems the "default" case in the DRI documentation is a $0400 loader and a
128KB version of CP/M-68K. If the same can be done with the CompuPro binary
images that would be a good place to start.
Assuming you are using an S-100 4MB SRAM board, the most direct path may be
to just use the debug monitor to load the default CP/M-68K binary image into
RAM and tweak the CBIOS from there. The DRI documents say for a "bare
bones" CP/M-68K the CBIOS needs about a dozen functions or so like the
console in and out and those for the disk.
I imagine the code required for interfacing to an S-100 IDE or S-100 ZFDC
could be considerably simpler than a Disk1A. Still a lot of work but
Once even a bare bones CP/M-68K is running then its own tools are available
to help fill out the rest. Its that first step that's the big one!
Good news on the S-100 68K CPU board PCB trace routing. As of last night
there were 584 vias and overall trace length at 1450" or so. At the rate it
was going it should complete a full pass in 2-2.5 days.
This is huge progress and the board has finally turned the corner. It still
needs to lose about 200 vias to be even reasonable to make a prototype but
at least it is visibly moving.
This is very exciting. With Leon's Z80/8086 multiCPU running "in the field"
I can see a day in the not to distant future of a Z80/8086/68K multiCPU
S-100 system. More to come for sure!
Thanks and have a nice day!
On Dec 27, 5:13 pm, "John Monahan" <mon...@vitasoft.org> wrote:
> My first choice would definitely be using the Godbout 68K image and
> splicing in a BIOS written in assembly. The Godbout/CompuPro systems
> we're outstanding. The documentation was great with great examples.
> That would be my first choice. It would be real easy to splice a BIOS
> into the very simple monitor I wrote, see here:-
> As to a windows based 68K assembler. I would highly
> It is just fantastic for a job like this.
> John Monahan Ph.D
> -----Original Message-----
> From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com]
> Behalf Of Mike
> Sent: Tuesday, December 27, 2011 12:47 PM
> To: n8vem...@googlegroups.com
> Subject: Re: [N8VEM-S100:607] Re: S-100 68K CPU board status
> On 12/27/2011 03:28 PM, lynchaj wrote:
> > Woof! OK, that's weird.
> > My guess is Alcyon C compiler is really old and predates much of the
> > now more standardized C conventions.
> > I've never seen or heard of anything like you just described. This
> > must be really obscure stuff.
> > Here is a post on comp.os.cpm which seems to discuss the unnamed
> > structs
> > Forgive my ignorance but do you think the Alcyon C compiler is
> > capable of successfully compiling the CP/M-68K sources?
> > Thanks and have a nice day!
> > Andrew Lynch
> Ha. Okay, so I'm not alone! :)
> Yes, I would say almost certainly it should be able to compile the
> CP/M-68K sources, as it appears to be the exact compiler used to
> compile them originally.
> http://8bit.zapto.org- Hide quoted text -
> - Show quoted text -