HowToFixComputers.com

Michael Campbell · Guest

Hi, I have just started to rebuild a vintage DOS/Win3.1 Gateway 2000
4DX-33 PC from 1992. It has a Cirrus Logic graphics chip right on the
mother board. If I put a ISA graphics card into one of the open ISA
slots, will that cleanly take over from the motherboard graphics chip,
or just smoke the new card, the old chip, or both? :-) Thanks.

Ben Myers · Guest

An ISA graphics card will not smoke the motherboard or itself, but I have no
idea whether it will take over as the graphics controller in the system. I
never tried this back when I was messing with these computers. Back in '93 or
'94, the motherboard manufacturers were not as experienced as they are right
now, so the switchover from on-board to ISA graphics may or may not go smoothly.

Unless the ISA card has a lot of video memory (2 or 4MB was a HUGE amount in
those days), there won't be a lot gained from installing one.

This is obviously a low-profile Gateway 486 with on board graphics. There were
exactly two models built with only ISA slots on the riser card. One is a very
large oblong Anigma design, and the other is an almost square Intel-made board.
Which one do you have? I have to dig out my specs for these boards, but it may
be possible to plug some chips into open sockets to increase graphics memory.

.... Ben Myers

On Mon, 02 Apr 2007 15:31:08 GMT, Michael Campbell <mac57@mindspring.com> wrote:

Michael Campbell · Guest

Thanks for the response. I think I have the square Intel-made board you
mention. I have checked - there are no open sockets around the Cirrus
Logic graphics chip. I guess I will find out the hard way - at eBay I am
bidding for a 2 MB Diamond Speedstar 64 ISA graphics card. If I win, and
when I get it, I will post back and let you know if it worked! I agree
that in those days, many computers sold with only 4 MB of main memory,
much less 4 MB of video memory. I figured 2 MB was as much as I would
find. Having found one, I guess I will try it and see.

Meantime, it is pretty neat old PC. The CPU was in a ZIF socket and I
was able to just recently upgrade it with a DX4-100 Overdrive chip. The
machine really churns along now relative to it's initial state. I also
have a memory upgrade to 16 MB coming soon - it came with 8 MB. That
will help it to move a little faster, or at least do a little more, than
it was initially capable of. All of this via eBay... it is amazing what
you can find on eBay these days for very little money!

As a final struggle, and really the main reason for getting this thing
up and running at all, I am trying to get SCSI up and running on it so
that I can regain access to a SCSI ZIP drive I have and a SCSI Jaz drive
I have. I am bidding on two different Adaptec ISA SCSI cards right now
on eBay - hopefully I will win one of those and be able to move forward.

Ben Myers wrote:

Ben Myers · Guest

IIRC and without damaging my brain by reading the specs, the motherboard
supports 32MB of system memory, a pair of 16MB fast page mode 72-pin parity
SIMMs.

You want a couple of Adaptec ISA cards? I have some here. At this point,
figure $5 apiece + exact shipping.

You're already in good shape with the DX4-100 OverDrive. I once sold kits,
mostly to Gateway owners, consisting of the 133MHz AMD Am5x133 486-workalike,
and cache chips which plugged into board sockets. The added cache memory made a
lot of difference in the 486 systems. Yeah, I still have a few tubes of cache
chips here... Ben Myers

On Mon, 02 Apr 2007 18:00:06 GMT, Michael Campbell <no@spam.net> wrote:

Michael Campbell · Guest

Thanks Ben! I will keep that in mind. I am bidding on an AHA-1522, and
the auction closes in just a little over an hour. So far, I am the only
bidder, which is good. If it should turn out to not be successful, I may
post back and ask what models you have available!

Thanks as well for the info on the cache chips. I had another look, and
there are no open sockets anywhere on the board. So, I guess it is
topped up with cache. Too bad, I am always in for anything that speeds
my computers up.

BTW, before I found the 4DXODPR100 Overdrive chip (it was new-in-box,
original shrink wrap, the works - great find) I had stumbled upon one of
the AMD 133 upgrade chips you mention, from Evergreen. I ordered it as
well (actually, it was the first one I found), but now that I have the
DX4100, I doubt I will even take the AMD chip out of the box. $19.99
wasted. Oh well... :-)

Ben Myers wrote:

Ben Myers · Guest

The AMD kit I sold was hand-assembled from off-the-shelf electronics.
Evergreen's kit has a surface-mounted chip on an adapter. The kit I sold had
ZERO compatibility problems with 486 boards. For a while, Evergreen had
serious compatibility issues with many Gateway boards, so I was able to sell
quite a few kits at $149 back when. Then Pentium systems came along.

I have only Adaptec 1540 cards with a hard disk BIOS that you absolutely need to
have to boot from a SCSI drive. I cannot recall anymore if the 1522 has a
BIOS. It's been too long, and I never handled many 1522s which are low-end
compared to the 1540.

If your motherboard has 9 32Kx8 SRAM chips 15ns or faster in sockets U10, U14,
U15, U20, U23, U26, U29, U35, U40, it is maxed out at 256K cache. If it has 9
8Kx8 SRAM chips 15ns or faster, it has only 64K cache... Ben Myers

On Tue, 03 Apr 2007 01:06:21 GMT, Michael Campbell <no@spam.net> wrote:

Michael Campbell · Guest

Thanks again Ben. I will check the motherboard and see what type of
chips are on the board. If it does look upgradeable, how much would it
cost to buy the 8 32K chips? You said that maxing the cache makes a
pretty significant performance difference - have you ever been able to
quantify how significant the difference is?

I ultimately lost the eBay bid for the AHA-1522a; I was the high bidder
right up to about 30s prior to closing, and then someone managed to
scoop me right at the end. Oh well...

In the meantime, I found a Jaz Jet SCSI adaptor, specifically from
Iomega, for Jaz and Zip disks, and I won that one. So, I think I am
"good to go".

Let me take a real leap here. Like most PCs of the era, my DX-33 has a
pretty loud power supply fan. Any chance that you have anything lying
around that could be used to replace it with a much quieter one? Else I
may try looking around for a fresh power supply that makes much less
noise. I remember several old Micron PCs I had from the same time frame
that were also pretty noisy. I guess that was "par for the course" at
the time. If you have anything, I could be interested. Thanks.

Ben Myers wrote: