Tall Tree Systems`JRAM-3'

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Sun Dec 2 13:50:14 2001

On Sun, 2 Dec 2001, Robert Schaefer wrote:
> Cool! Any chance you have some docs on it?
Yes, but not today.

> to it yet, altho I did power up the system a few times. Once made it as far
> as `PARITY 1 ERROR', most times it just sat there with the cursor blinking.

It is absolutely NOT needeed for bringing up the computer, so pull it out,
and keep it out until the computer boots and runs properly.

PARITY 1 ERROR is ususally memory problems on the motherboard.

> I've been reseating all the chips. Got a little too smart tho-- I pulled
> one out to jam it back in, it came out crooked and broke two pins off.
> :( If I can't find a spare off another board, I'll see about soldering the
> pins back on.

It's very ordinary 64K(bit) DRAM. Shouldn't be a problem finding, and you
could always disable that row of 9, and use the rest.
If that was on the motherboard, it COULD be a 256K (simple mod on XT to
run 2 rows of 256 and 2 of 64 for 640K total).
On an EARLY 5150 PC, it could be a 16K.


> BTW, the MB has a V20. Is that stock on an IBM-branded XT?

No. But it was a common add-in. The V20 was a plugin compatible
replacement for the 8088. It added an 8080 (not Z80) mode that was handy
if you're heavily CP/M oriented, and provided an average throughput
improvement of about 7% over the 8088. Since the performance improvement
was a function of what instruction mix you use, it varied from -30%? to
+200%, and was often sold to suckers as a 200% speedup.
It also used less power, and was handy in systems running off of
batteries.
(NOTE: to use a V20 in a Gavilan required some board mods!)

> > The card is ALL memory, with just a few "glue" chips. There is no
> > multi-function stuff on it.
> > The "daughter" cards, on the other hand, have all sorts of weird stuff.
> What kind of weird stuff? Interesting-weird or strange-and-useles-weird?

Yes

> > Want to buy a few?
> daughterboards or cards?

Yes


I'll try tomorrow to see if the more accessible tote of them has
docs/software for the JRAM-3, and let you know.

--
Grumpy Ol' Fred        cisin_at_xenosoft.com
Received on Sun Dec 02 2001 - 13:50:14 GMT

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