Multi-User CP/M Computer For Sale
Derek Schwartz
I have a Discovery 500 Multiprocessor system that has an 80186 and two Z80's.
It runs CP/M under a master control program that allows you to use the 186
as a controller while running the Z80's independently. Each Z80 has it's own
serial connection so two people can be using the system at once. Or, you can
kill the MCP and use the 186 directly which will then use the Z80's as slave
processors for math and I/O funcitons. It's really a nice (BIG and loud)
system. It has two 640k floppy drives, a 20-meg SASI hard drive, 64k of RAM
all the original books, manuals, schematics, an extra 10-meg SASI hard drive
with controller card (NEW, never used!), and two Wyse-50 terminals. It's
running CP/M-86 on the 186, and CP/M 3.0 on the Z-80's. I've been keeping
this thing around thinking that I would really dive into it someday. Reading
all the old literature really gives you a strange feeling since it's all in
plain English. The HD is loaded up with stuff like a C compiler, WordStar
(have original docs), a data base program, lots of text files and
source-codes. I even have a few boxes of 640k disks for it (must be hard to
find) which have all kinds of extra language compilers and OS stuff. A
letter was included with the manuals that listed the original selling price
back in the '70s to be around $20,000!!! Who knows what it's worth now
though?!!!?! Anyway, I've seen nothing that can even compare to this system,
so I have no way of knowing what it's worth. It's about 10 times faster at
program execution than my C-128 running CP/M. Any offers?
Oh yeah, I also have an IMSAI 8080. It's the S-100 box with all the direct
register switches on the front. They work too, because I keyed in a 2k
program that took me about 3 hours! Anyway, this thing includes two dual-8"
floppy drives (which sound like jet engines) and a home-made keyboard. It
has a monochrome video card that can be used on any composite monitor. I
have a ton of 8" disks for it too, but I don't have a cable to hook up the
disk drives. The schematics for building one are included though... :) I
even have an original ZORK 8" floppy game with it's original packaging. I
have a Hayes-300 modem too. This system was owned by an electronics engineer
who built it from a kit. He said he paid around $10,000 for the kit back
then. I'd sure never trust my soldering technique where $10k is concerned!
:| Anyway, I'll take offers on this too. I have just as many manuals and
books for this as I do the Discovery 500.
Derek Schwartz
forb...@gnn.com
Jeff Jonas
In article <4sn5td$g...@news-e2b.gnn.com> forb...@gnn.com
(Derek Schwartz) writes:
>I have a Discovery 500 Multiprocessor system that has an 80186 and two Z80's.
*drool* I am still interested in affordable multiprocessors and
asymmetric multiprocessors (such as your system with the controllers).
I still plan on rejuvinating my Z80 systems as SCSI controllers to my
Pentium Linux machine. I'm saddened that the Z80/'86 hybrids barely survived.
> It runs CP/M under a master control program that allows you to use the 186
>as a controller while running the Z80's independently. Each Z80 has it's own
>serial connection so two people can be using the system at once. Or, you can
>kill the MCP and use the 186 directly which will then use the Z80's as slave
>processors for math and I/O funcitons.
I'm really curious if there was much OS support for them,
or was it all roll your own?
> It's really a nice (BIG and loud)
>system. It has two 640k floppy drives, a 20-meg SASI hard drive, 64k of RAM
>all the original books, manuals, schematics, an extra 10-meg SASI hard drive
>with controller card (NEW, never used!), and two Wyse-50 terminals.
*further whimper*
I have a Wyse 50 and 60 for CP/M machines,
and many Xerox 820-IIs (built in display).
It's kinda nice to know some are still out there.
> It's
>running CP/M-86 on the 186, and CP/M 3.0 on the Z-80's. I've been keeping
>this thing around thinking that I would really dive into it someday. Reading
>all the old literature really gives you a strange feeling since it's all in
>plain English. The HD is loaded up with stuff like a C compiler, WordStar
>(have original docs), a data base program, lots of text files and
>source-codes. I even have a few boxes of 640k disks for it (must be hard to
>find) which have all kinds of extra language compilers and OS stuff. A
>letter was included with the manuals that listed the original selling price
>back in the '70s to be around $20,000!!! Who knows what it's worth now
>though?!!!?! Anyway, I've seen nothing that can even compare to this system,
>so I have no way of knowing what it's worth. It's about 10 times faster at
>program execution than my C-128 running CP/M. Any offers?
Gee, I've been giving away stuff since I'm out of space.
>Oh yeah, I also have an IMSAI 8080. It's the S-100 box with all the direct
>register switches on the front. They work too, because I keyed in a 2k
>program that took me about 3 hours! Anyway, this thing includes two dual-8"
>floppy drives (which sound like jet engines) and a home-made keyboard. It
>has a monochrome video card that can be used on any composite monitor. I
>have a ton of 8" disks for it too, but I don't have a cable to hook up the
>disk drives. The schematics for building one are included though... :) I
>even have an original ZORK 8" floppy game with it's original packaging. I
>have a Hayes-300 modem too. This system was owned by an electronics engineer
>who built it from a kit. He said he paid around $10,000 for the kit back
>then. I'd sure never trust my soldering technique where $10k is concerned!
>:| Anyway, I'll take offers on this too. I have just as many manuals and
>books for this as I do the Discovery 500.
*That* is a collector's item, after the Altair.
Computer museums might be interested in that, and if tax deductable
donating it may be worthwhile.
My bookmarks show:
http://www.tcm.org/
The Computer Museum in Boston, Mass.
http://www.ncsc.dni.us/fun/user/tcc/cmuseum/cmuseum.htm
the Obsolete Computer Museum
http://exo.com/~wts/wts10005.HTM
The Virtual Altair Museum
MITS/Pertec Altair 8800/680b/MITS 300/Attache
and the stories of those who build and use them
http://swift.eng.ox.ac.uk/rjm/museum.htm
Bob's computer museum in Oxford, United Kingdom.
has good links to other sites of interest, such as
http://www.chac.org/chac/index.html
Computer History Association of California, Palo Alto, CA, USA
--
Jeffrey Jonas
je...@panix.com
Don Maslin
Jeff Jonas (je...@panix.com) wrote:
**** snip ****
: *drool* I am still interested in affordable multiprocessors and
: asymmetric multiprocessors (such as your system with the controllers).
: I still plan on rejuvinating my Z80 systems as SCSI controllers to my
: Pentium Linux machine. I'm saddened that the Z80/'86 hybrids barely survived.
Jeff, if you are really interested in multi-user/processor systems, I
would strongly urge that you take a look at TurboDOS and one of the
many board sets that supported master/slave relationships. It is
clearly superior to any of the other CP/M related operating systems in
this type of application.
- don
do...@cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
john r pierce
Jeff Jonas (je...@panix.com) wrote:
>
>**** snip ****
>
> *drool* I am still interested in affordable multiprocessors and
> asymmetric multiprocessors (such as your system with the controllers).
> I still plan on rejuvinating my Z80 systems as SCSI controllers to my
> Pentium Linux machine. I'm saddened that the Z80/'86 hybrids barely survived.
?? A Z80 class CPU is going to have a hard time keeping up with the
10MB/s (fast scsi-II) to 40MB/s (ultra-wide SCSI-II) burst xfer speed
of modern SCSI hard disks, not to mention the 100MByte/sec sustainable
burst speed of the PCI bus... The original Z80 topped out at around
8Mhz, I believe(?) which with its 4 clock per 8 bit cycle resulted in
a peak memory bandwidth of 2Mbyte/sec... at a read and write per data
byte moved, thats only 1 MByte/sec, hardly enuf to keep up with my 6X
CDROM drive (and thats not allowing for instruction fetch time)...
Now, I know that some of the Z80 compatible processors are several
times faster than this, but still... A better choice for a high
performance scsi subsystem controller for a pentium eunichs system
might be a Intel i960RP risc engine combined with 2 or more PCI
ultra-wide scsi channels on its second bus...
-jrp
Jeff Jonas
>> Pentium Linux machine. I'm saddened that the Z80/'86 hybrids
>> barely survived.
In article <31f196fd....@news.scruznet.com> pie...@scruznet.com
(john r pierce) replied:
>?? A Z80 class CPU is going to have a hard time keeping up with the
>10MB/s (fast scsi-II) to 40MB/s (ultra-wide SCSI-II) burst xfer speed
>of modern SCSI hard disks,
Gee, my Adaptec 1542CF is fast scsi and uses a Z80 CPU.
The cabinet is not open so I can't see if it's 10 or 20 MHz.
The CPU is used for command processing. Data transfers bypass
it directly via DMA and FIFOs and such.
My Ampro litleboard has a 53c80 SCSI chip on it, so I believe I can
achieve formitable transfer rates although the command processing may not
be as zippy as I'd like.
> not to mention the 100MByte/sec sustainable
>burst speed of the PCI bus...
My PCI SCI controller consists primarily of the Symbios/NCR 53c825 chip.
No CPU at all.
Overall, it does not sound so difficult to achieve
reasonable transfer rates
--
Jeffrey Jonas
je...@panix.com
Alan Cox
In article <4stjs4$m...@panix2.panix.com>, Jeff Jonas <je...@panix.com> wrote:
>My PCI SCI controller consists primarily of the Symbios/NCR 53c825 chip.
>No CPU at all.
Beg to differ. The NCR 53c825 is a processor all of its own. You'll find an
assembler for it (written in perl) in the Linux source tree. Its a very
specialised processor in that most of its instructions are things like
"wait for XX on bus", and "blast large block of data from X to Y", but you
can use it for stupid things like playing noughts and crosses if you
really want.
Alan
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