nather@utastro.UUCP (Ed Nather) (07/15/85)
> I'm looking for a clock/memory board, too.
We are the proud (?) owners of three IBM PC portables -- the heavy computer
with three (3) long slots, total -- and found an interesting solution to the
clock/memory problem that involved no slots at all, long *or* short. Since
the portables use the XT motherboard, we were able to replace two rows of
64K chips with 256K chips on the motherboard, thus getting 640K. We also
added a "dClock" card that contains the standard battery-powered clock/
calendar, but sits on the motherboard by plugging into the 8088 socket.
(It has a socket for the displaced 8088 directly above).
The memory modification involves adding one small jumper to the board, and
was described in this newgroup about a month ago. The "dClock" is sold by
Microsync, Inc., P.O. Box 116302, Carrollton, TX 75011, for $60. The 256K
chips cost us $90 per portable, and they're less now.
More details on request.
--
Ed Nather
Astronomy Dept, U of Texas @ Austin
{allegra,ihnp4}!{noao,ut-sally}!utastro!nather
nather%utastro.UTEXAS@ut-sally.ARPAres@ptsfa.UUCP (Bob Stockwell) (07/16/85)
I have a columbia MPC (IBM-PC clone) that can take any expansion boards built for IBM. I am in the market for a memory board with a clock/calendar. I don't need any serial or parallel ports as they came with my system. I have two questions for the net. 1) I have 128K in my system, so I would like a board with capability for 512K instead of the usual 384K. Do most boards contain dip-switches to configure memory to start at 128K or whatever? 2) Can anybody make any recommendations? Bob Stockwell, Pacific Bell
timothym@tekigm.UUCP (Timothy D Margeson) (07/17/85)
T'was brillig, and slithy .... Don't try to use any memory cards that have ram beyond 640K or you'll be sorry! Actually up to B8000 you will be safe, maybe. Depending on your clone. If ram exists, or is enabled beyond 640K bytes, you run the risk of having a buss contention problem between the ram and video memory, hence a system crash or funnies. I have a COMPAQ Deskpro and ran into that problem, but also tried a normal portable variety COMPAQ and did not seem to have the problem. Confused? Stick with 640K on an IBM clone to be safe. BTW, I have used several of the AST cards in various computers at work, and have not yet seen one fail or cause problems. The problems I experienced on my machine was with a Quadram board. I now have an AST board instead. ta ta. -- Tim Margeson (206)253-5240 tektronix!tekigm!timothym @@ 'Who said that?' PO Box 3500 d/s C1-465 Vancouver, WA. 98665
stv@qantel.UUCP (Steve Vance@ex2499) (07/19/85)
I'm looking for a clock/memory board, too. What about this "Tall Tree
Systems J-RAM" board I've seen in the ads? It is the same price,
features, etc. as everyone else, except you can expand it to 2Meg
instead of the 640k maximum AST and everyone else has. Why would
anyone buy anything else? This is a serious question, since I
just bought my PC-compatible a couple of weeks ago.
--
Steve Vance
{dual,hplabs,intelca,nsc,proper}!qantel!stv
dual!qantel!stv@berkeley
Qantel Corporation, Hayward, CAdmt@mtgzz.UUCP (d.m.tutelman) (07/19/85)
> Don't try to use any memory cards that have ram beyond 640K or you'll be > sorry! > > Actually up to B8000 you will be safe, maybe. Depending on your clone. Actually, it depends on your display board more than your clone. The color graphics display memory starts at B8000, while the monochrome starts at B0000 (allows both display boards without bus contention). You lucked out at B8000 because the built-in display in the COMPAQ emulates the color board, as does the AT&T PC6300. Dave Tutelman Physical - AT&T Information Systems Holmdel, NJ 07733 Logical - ...ihnp4!mtuxo!mtgzz!dmt Audible - (201)-834-2895