Minimal CP-M SBC design

[Allison]

>
>Subject: Re: Minimal CP-M SBC design
>   From: Ethan Dicks <ethan.dicks at usap.gov>
>   Date: Sun, 11 May 2008 13:01:31 +0000
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>     Cc: General at icecube.southpole.usap.gov,
> On-Topic Posts Only <cctech at classiccmp.org>
>
>On Sun, May 11, 2008 at 08:23:13AM -0400, Dave McGuire wrote:
>>   Well I wasn't talking about a diskless system...only one in which 
>> CP/M itself was in ROM.
>
>I personally find the idea intriguing, and I am about to cobble up
>a system from (nearly) scratch.  I used Kaypros and the like, back
>in the day, and really won't miss floppies (not that there's an FDC
>chip within 3000 miles I could slap on this thing, anyway).
>
>I don't mind the idea of stuffing "the OS" in ROM vs loading off
>of removable media since I doubt I'll want to upgrade.  I want to
>run a few CP/M-80 programs, and that's about it.

NOte It's not OS in rom, it's Rom as floppy replacement.  CP/M load 
process for floppy is a booter load system tracks to ram.. The rom 
appaorach is booter loads system from ROM to ram. and once in ram 
you can overlay, alter, patch, extend as desired.


>> >I still don't have the hang of this "vintage" thing yet, probably 
>> >because I'm vintage myself.  Please forgive my density...
>> 
>>   I often suffer from the same problem.  I think very few of us, even 
>> here, actually used stuff like CP/M and PDP-11s when they were 
>> considered current technology.
>
>I was a kid when S-100 machines were "in", but, as came up earlier
>in this thread, I did hit the Osborne/Kaypro CP/M era.

When I was an adult S100 was introduced.


>I consider myself quite fortunate that I've gotten to program PDP-11s
>on two different jobs right at the tail end of their heyday (I was 18-20
>at the time).  I also consider myself fortunate that I was working at
>a place that supported VAX/BSD customers in addition to our VAX/VMS
>customers, so I was able to pick up some UNIX skills nearly 25 years
>ago.  When folks bandy about "All the World's a VAX", it really means
>something to me (I learned C from K&R on an 11/750 running 4.1BSD, so
>I _know_ how easy it is to write non-portable code).
>
>I do run things inemulation, but I also enjoy running things on real
>iron.  Right now, I have a modern Elf within reach, as well as an
>SBC6120.  The SBC6120 boots off of CF... no floppies, no 1/3 HP rotating
>media, but there's still a real 12-bit processor on the board.  I don't
>consider that emulation in the slightest, even if my "disks" don't rotate.
>OTOH, I also have, at home, "real" PDP-8s with real DEC-made disks; they
>just aren't so portable as to be worth hauling down here.  Same goes for
>a CP/M machine - I'm working on something smaller than a princess phone.
>Quite portable compared to an S-100 or an Osborne.

Bob's SBC6120 is as close or better than a real 8e for playing with code.

That s the point too. Emulation you just cant pay with wires or add 
a parallel port.

>Just my take on why I mix classic CPUs with modern peripherals... runs
>the original software, weighs a lot less.

;) and it can be faster too.  A 64K z80 system that has a 32mb CF will do 
everthing the same as my S100 create with a Quantum D540(32mb) hard disk
only it cant cause back pain, it's about as fast and the CF based machine
can run on small batteries where the S100 crate can suck up a APS 1000VA 
UPS in short order (that has two 12V 7AH gell cells or ~168WH of power).


Allison

>-ethan
>
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>Ethan Dicks, A-333-S     Current South Pole Weather at 11-May-2008 at 12:40 Z
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>
>Ethan.Dicks at usap.gov            http://penguincentral.com/penguincentral.html