VOGONS


First post, by Anonymoose

User metadata
Rank Newbie
Rank
Newbie

Heyo,
Per the title, I’m a bit confused on how to trick out my Compaq Deskpro 4/66i.

I’ve found a website describing the board, says it takes 32mb (4 banks of 8mb?) and a VRAM expansion. When I google vram expansions, all I get are modern day gpu upgrades and whatnot. What should I be looking for? This vram upgrade is a bit foreign to me.

There’s also a 486 cache slot. What is that? Would it benefit adding one to the computer? I’m unsure.

Attachments

  • IMG_5121.gif
    Filename
    IMG_5121.gif
    File size
    22.82 KiB
    Views
    451 views
    File license
    Public domain

Reply 1 of 15, by dominusprog

User metadata
Rank Member
Rank
Member

According to the manual the board has 4MiB of onbaord RAM, so you have to install two 8MiB and two 4MiB for totall of 28MiB of RAM. For the VRAM, it seems that the board has its own proprietary connector for expansion.

https://theretroweb.com/motherboards/s/compaq … v-3-p-n-00#docs

Duke_2600.png
A-Trend ATC-1020 V1.1 ❇ Cyrix 6x86 150+ @ 120MHz ❇ 32MiB EDO RAM (8MiBx4) ❇ A-Trend S3 Trio64V2 2MiB
Aztech Pro16 II-3D PnP ❇ 8.4GiB Quantum Fireball ❇ Win95 OSR2 Plus!

Reply 2 of 15, by Horun

User metadata
Rank l33t++
Rank
l33t++

The video upgrade and cache module are very proprietary, the video upgrade has 1Mb vram on a flat card. Current Vram shows 4 - 256k x 8 for 1Mb.
Cache consisting of an Intel 82485 cache controller plus 64k of L2 cache also on a flat card like this:.
https://www.amibay.com/threads/compaq-23052-a … o-4-66i.106879/

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 3 of 15, by rasz_pl

User metadata
Rank l33t
Rank
l33t

cache is unobtanium
Vram upgrade is pointless, what even is the VGA chip on this board? looks like something Compaq cooked themselves and got manufactured by LSI? Is it VLB? is it half decent?
4/66 means the only CPU upgrade possible is with Overdrive or one of those Socket 1/2/3 Voltage Interposer Tweaker (Alpha)

Open Source AT&T Globalyst/NCR/FIC 486-GAC-2 proprietary Cache Module reproduction

Reply 4 of 15, by Horun

User metadata
Rank l33t++
Rank
l33t++

Hmm going thru wayback machine think that could be a remarked Qvision, my guess a Qvision 1024 per the doc at TRW.
The 4/33i and 4/66i share all the same files and this be the video driver:
http://web.archive.org/web/20040731174129/htt … ocate/3_51.html
http://web.archive.org/web/20040701081037/htt … nload/1051.html
Wasn't the Qvision used on Compaqs EISA video cards ???

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 5 of 15, by PC Hoarder Patrol

User metadata
Rank l33t
Rank
l33t

Yes QVision (the Motorola chip rather than LSI)...@Robert B showed the VRAM upgrade module a year or two back

CPQ VRAM.jpg
Filename
CPQ VRAM.jpg
File size
973.01 KiB
Views
342 views
File license
Fair use/fair dealing exception

Reply 6 of 15, by Anonymoose

User metadata
Rank Newbie
Rank
Newbie

Ah, so the vram is difficult to get, that’s fine. And It is a Qvision 1024, you’re correct.

As for the memory, the board has 4mb of onboard ram? The bios says there’s 4mb of ram, but there’s a card in bank A of the memory module slot. Is that correct?

Reply 7 of 15, by Anonymoose

User metadata
Rank Newbie
Rank
Newbie

Back again with another question, rasz_pl said “4/66 means the only CPU upgrade possible is with Overdrive or one of those Socket 1/2/3 Voltage Interposer Tweaker (Alpha)”. Is that it for cpus? I can’t find much on the board, but what about interposers or something? Any possibilities of 133mhz?

Reply 8 of 15, by rasz_pl

User metadata
Rank l33t
Rank
l33t

Pentium overdrive will require one of those Voltage Interposers blocking 5V from motherboard and feeding CPU its own 3.3V

Open Source AT&T Globalyst/NCR/FIC 486-GAC-2 proprietary Cache Module reproduction

Reply 11 of 15, by Anonymoose

User metadata
Rank Newbie
Rank
Newbie

Ok, so the MMX overdrives are specifically for Pentium computers and not compatible with the 486. With that being said, I got this information from the Wikipedia page, and the wording confuses me on whether it’s 5 or 3.3

Reply 12 of 15, by waterbeesje

User metadata
Rank Oldbie
Rank
Oldbie

Yes, Vramis unobtanium. Is lijkt to have one for my Deskpro XE 4/66.

Yes, the cache module gives you quite some extra performance. I'm lucky enough mine has the module but I haven't seen another one around.

I've put in 4x 16MB ram and it still didn't go over 32MB available. As with 2 modules. With 1 module it went straight to 20MB total. Also note the onboard 4MB ram is 70ns so putting in 60ns ram won't make it faster.

In all it's a nice 486 system. It's fast enough with the L2 cache and the video chip is better than average imo.
The windows bios is stored on the hard drive, in a separate partition, so that's something to keep in mind.

Oh befor I forget to mention: the latest bios supports the pod CPU.

Stuck at 10MHz...

Reply 15 of 15, by PC Hoarder Patrol

User metadata
Rank l33t
Rank
l33t
Anonymoose wrote on 2024-06-18, 00:23:

Thanks! Would you happen to have information about finding the latest bios?

Systems shipped with a number of different board / ROM revisions - which is yours (should be on a labelled chip next to the Dallas RTC)