pcoen@drew.edu (Paul Coen) (06/05/90)
I'm posting this for a co-worker. Please address replies to
bcampbel@drew.edu or bcampbel@drunivac.bitnet. As our incoming
Newsfeed is down due to campus politics, only direct mail replies will
be seen. A summary will be posted to the net. Thanks in advance.
--paul
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I'm trying to add a Zenith 1 meg memory expansion card to a Zenith 20 Mhz 386
machine. The model number of the computer is ZBO-3521-ED. (I don't know
how useful that is.)
Anyway, the system currently has 1 meg of memory on the mother board.
640k base memory and 256k ems (or extended. It's easily configurable through
the setup program.) The mother board uses either 1 or 4 meg SIMMs (Single
Inline Memory Modules). There is currently room for seven more.
The owner's manual for the system says up to three add on memory cards can
be used in the 32-bit slots. It suggest the use of a Zenith ZA-3600-MQ
card, but elsewhere, hidden in the manual, it seems that some third party
cards will work.
I've been given a Zenith Z-505 1 meg memory expansion card and am trying
to use it to add an extra meg to the system. (In the world of academics,
we use what we can get.) Zenith says it can only be used with their
386/16mhz machine which uses the 505 as base memory and for expansion.
Zenith isn't always completly right. The card I have worked in a 386/16
I borrowed to test it, but I can't get it to do anything in the 386/20 I have.
From playing with the dip switches and reading both the manual on the card
and on the system, I've gotten it to sit in the pc without it kicking out
any error messages, but it's not recognized by the system as far as I can
tell. If I set the extra meg as ems memory and try to use emm.sys (a
zenith device driver for ems memory) the machine locks. Emm.sys worked
fine when I take out the extra card and just use the 256k of ems.
I would greatly appreciate any help or ideas on how I can get it working.
I'm setting up a small LAN for a BBS and the extra meg would be very
useful. Email is preferred over a posting to the discussion, but I'll
take anything I can get.
Bill Campbell
System Manager - Drew University Undgerground BBS
bcampbel@drew.edu
-----------------------------end of message------------------------------------cak@vpnet.chi.il.us (Cindi Knox) (06/09/90)
Zenith reworked their extended bus specification between the 16MHz 386
and the later versions. The reason the third party board will work is
they are based on the PC-AT bus. While they will not run as fast as the
Zenith boards (running with multiple wait states and 32:16 bit conversion)
the after market boards fit the AT bus as specified by IBM and supported
by Zenith. The 32 bit boards, however, run at a different speed (note the
access time stamped on the RAMs and the delay taps on the delay lines)
and the faster Zenith computers simply ``won't wait'' for the slower RAM.
Since the old 32 bit boards were designed for 0 wait state operation, no
provision was included to drop the /READY signal to the microprocessor.
Also, I understand the pinouts have changed slightly in a nod to EISA on
the newer equipment. If you *DO* get this board to work, please let me
know. 1) I like surprises and 2) I collect wild Zenith configuration ideas.
(I was among the first to have a 10MHz ZW-241).
Cindi Knox | You've got a lot of living to do without life.
|
cak@vpnet | ``Little Miss S.'' by Edie Brickell and New Bohemians.