news@bungi.com.mu.edu (05/14/91)
Today I ran across an advertisement in a surplus magazine ("Nuts & Volts")
which might be of interest to some of you wanting to expand their PC532.
But first I need to digress a bit to frame the context. A while back
it struck me that a full height drive bay (approx. 5.875' x 3.375" x 8.0")
could house a 4-slot PC. This assumes that a CPU card is employed with
a passive backplane, and all cards are less than approximately 8 inches
in length.
Ok, now the advertisement. On page 8 of the May 1991 issue of "Nuts &
Volts Magazine" is an add by ERAC Co., Poway, CA, tel (619) 679-8360.
In particular the advertisement lists:
1). ERAC Special, 80286-12 CPU Card (Action Instrument), G2-TAG Chip
set, award bios, 1/2 size, 4 Meg simms (0k), 1 Parallel, 2 ser (232/422),
Dallas clk, instruction manual. $150.00
2). 80286 Turbo 10/6 CPU card, 640k ram on board, uses backplane, Phoneix
bios, with manual. $129.00
3) 80286-8 CPU card, uses backplane and external memory board. Phoneix
bios, 80287 socket, diagram. $54.00
4) AT Passive Backplane, 8 slot with keyboard, & power connector, 6 AT
and 2 PC slots. 34.00
NB. The board length of items 2 and 3 is not indicated. Also something
like item 4 cut-down to 4 slots is really not needed since it
should be very straight forward to handwire a passive backplane.
I trust the above conveys the idea.. Of course a SCSI controller card
is still needed, but this is very straight forward and I can provide
construction plans such an animal.
Now with a PC expansion processor, (a few) things like ethernet can be added
inexpensively. For example, a Taiwan board, DFI carried by many mail
order houses, sells for $139.00. This board is virtually idential
to the NSC DP839EB Network Evaluation Board (see NSC "Data Communications,
Local Area Networks, UARTS Handbook" page 1-102, aka AN-479) as well as
the ET532 ethernet implementation. Actually, the board would make a
good source for ET532 parts :-).
Having suggested the above alternative, I need to tell you that I will
probably not go this way. I am looking into the possibility of using
the CSA "Transputer Educational Kit" add-on processor boards ($150.00 ea)
for expansion. More on this latter if things unfold favorably. However,
I doubt if many of you will find this avenue of real interest since it
will involve a fair amount of hardware hacking. For example mating
the transputer board with the above ethernet card will bypass the PC
edge connector and require trace cutting, some glue logic, etc.
Anyway, if the above idea strikes a cord with anyone -- grab it and
run.
Best regards,
johnc
--
John Connin: manatee Orlando, Florida
UUCP: {uunet,ge-dab,ucf-cs}!tarpit!tous!manatee!johnc