Rescuing a REMARKABLE 386 DX-25 Made by Compaq

We rescue a Compaq Deskpro 386/25m, a machine that is a bit of a hidden gem. Quite a number of things go right with this restoration and the results really speak for themselves.

If you need a setup utility, perhaps you can find one here:

I have no idea about the reliability of that site though. You need a version of the driver that has your machine. In my case sp6144 was sufficient.

[ultrametric]

All the performance bonus is coming from the EISA 32-bit bus and much more sophisticated DMA memory transfers. Even clone EISA machines were stark improvements in performance over ISA machines. Find yourself an old Adaptec 1710 (IIRC) SCSI card for it and an extended memory add-on board and it will rock! Don't forget the 80387.

[chateuaxfaygeaux]

It so happens my first encounter with the Unreal demo was on a 386SX-16 and it impressed me. Imagine my surprise when I finally ran it on a faster machine.

[pipschannel]

Super cool modular machine (The M stands for modular for it's modular design indeed).
I'm a huge Compaq fan and I have the 486m version of this unit (it has been upgraded from a DX-33 to a DX4-100 Overdrive CPU).. You can go as far as a Pentium 60 and 66 CPU card, which was also available, featuring a 128-bit Tri-flex front side bus which would be a huge upgrade from a 25MHz 386 and it's the only machine I know of that can pull this off! Pretty hard to find those Pentium CPU cards though.. The 486 is still available on Ebay and you could go as far as putting a 133MHz AMD 5x86 in them using an interposer socket with a voltage regulator which would make it perform on par with the 66MHz Pentium or thereabouts in terms of raw integer performance!

Oh and about the harddrive: It's indeed supposed to be mounted on its side on the right of the drive cage behind the power switch. This is how they left the factory, with the Connor drive mounted on its side ;-) Pretty weird design but it'll give you two free 5.25" drive bays..
Mine has a CD-ROM and Syquest drive in those slots..

"the previous owner's cause of death was..." priceless, LOL!

[benjaminrondeau]

That big BQFP chip next to the CPU is a 82395DX high performance smart cache controller with 16KB of integrated 4 Way set associative L2 cache. That right there will definitely leave a cacheless 386SX in the dust.

[scargo]

What a great video, thank you!

I have quite a few Compaq systems of this era and the /M (M-boxes) were the 3rd generation EISA machines from Compaq. The first Compaq EISA system (and 486) was the DeskPro 486/25 (released in late 1989, just prior to the first SystemPro server) and had an initial MSRP of $14k - $20.5k USD! The unit I have was outfitted with a 320mb ESDI drive (that amazingly still works!) and and 12MB RAM (probably would have been right in the middle of that price range). It was a more traditional layout (with the processor on the motherboard) only having a proprietary memory expansion board and modules (as well 16-color on-board VGA). The 2nd iteration of EISA was the DeskPro "L" that came in 386 and 486 flavors (and moved the processor to a proprietary card similar to the M). They share the same memory modules, but different memory expansion cards if memory serves.

To add more memory to your /M you'd either want the Compaq expansion board (129129-001) or the Kingston equivalent (KTC9160); the latter seem to pop up on eBay a little more frequently. They have 8 72-pin SIMM sockets for up to 64MB/memory total (including the 4mb or 8mb on the CPU board), so a bit easier/cheaper to populate with memory!

The /M systems either would have come with an EISA "Advanced VGA" card (640x480/256 color), QVision 1024 (1024x768), or the QVision 1280 (1280x1024). The latter 2 had optional (proprietary) 1MB memory upgrade modules. I've been on the hunt for a QVision 1280 card for my DeskPro 50M (486DX2-50), but they seem to be very scarce. As others have mentioned some of the later/faster ISA cards will outperform most EISA video cards, but my preference is to use EISA cards as much as possible in these systems (an Adaptec or Compaq EISA SCSI controller with SD2SCSI adapter really flies; a CompactFlash IDE adapter is a close second).

Back to the 386 models, the 386/20e or /25e were ISA systems (same chassis as your 386s), but were "enhanced" with an Intel 80385 cache controller and 64kb of cache. The 386s/20 was one of the last 386s produced in the same chassis but has 4 72-pin SIMM sockets on the motherboard (whereas the previous 386 models all needed the proprietary 16-bit or 32-bit memory expansion board with proprietary memory modules (different from the the EISA systems).

Lastly, I'd be more than happy to send an extra EISA NIC your way if you're interested.

[damouze]

The plasma effect in Unreal is in fact a little more than 'just' pallettecycling ;-). If I recall correctly, the effect also involves clever use of the VGA display parameters and vertical retrace interrupt to blend several images together to fake more than 256 simultaneous colours on the screen.

[BrassicGamer]

What a satisfying video. Great to see the performance of that DX - I only ever had an SX growing up, though it was 25MHz. Unreal ran, but I can't remember how well. I would love one of these EISA Compaq machines, especially with the matching peripherals. What a jewel!

[PaulinesPastimes]

What a nice machine. The Compaq designs were quite interesting and it's so early 90s, excellent. It's great that the CPU card matched and it worked so well. Way better than the clone beige box 386 I had back then. 😊

[joshhiner]

Back in the day I had a compaq deskpro 286n. It had a pizza box case. 12mhz I believe. It was quite the performer for a 286. Ive always liked the Deskpro lineup.

[paulstubbs]

Nice look at the end, although the monitor base looks likes it's been turned 90 degrees.
We had deskpro's where I worked in a telco, the one thing that stuck with me was the speed of the video, Other manufacturers harped on about this and that with their video cards & interface etc, yet the Compaq's left them in the dust, things just snapped onto the screen.

[AlexCruise]

My first PC compatible (an 8MHz Turbo XT clone) had a similar physical design, where the CPU and RAM were on a full-length daughtercard, and the motherboard was dumber. In my case the motherboard slots were all 8-bit though. It came with an ATI Wonder card that provided CGA and Hercules, and two half-height 5.25" floppies. I later installed an 84.9MB SCSI drive and started a BBS, of course!

[MM.]

Always a joy to look at these machines. There's something unique about Compaq's design language, a lot of thought put into little visual cues that make for a compelling organic-looking whole. Certainly a contrast to IBM's rather aggressive geometric look, slanted bezels and liberal use of ventilation slots on PS/2 machines.

[osgeld]

my second "my very own" computer was an ESIA 386DX 25 and it was a screamer, unreal was one of my favorite demos to run on it (my parents had recently gotten a fairly high spec 486 to run things like second reality) I used it mostly throughout high school where eventually I was able to work a job and pick up a pentium 90 as the MMX machines were in vouge

[CPUGalaxy]

Great video and very interesting computer. I have a lot of EISA boards and cards but never tried them out in terms of performance. Need to do that.

[highpath]

I think the M means the box size format, and the E means (E)uropean Spec ( EMEA sales area inc probably UK)

[PP-xybg]

It took me quite a while to realize that you are saying 80-386 processor. I needed to rewind the video a few times. It does sound like 8386. Even the auto generated captions transcribed it as 8386. And I was, wow - did not know about this chip. Was that an early 386 that I never heard about :)

[mogwaay]

Wow, real trash to treasure there! Great job finding that CPU card, they can't come up very often, lucky find. Love the shock & surprise when first the machine POSTs and the 2ndly when the HDD boots to DOS, I was with you there! Would be v interested to see the more conventional benchmarks of this, like TOPBENCH and Superscape results.

Im fascinated by the Compaq Deskpro 386 and think it deserves to sit beside the PC, XT and AT and one of the major early developments of the PC, but it doesn't get nearly as much attention as the IBM machines - ta for readdressing that to a degree. Perhaps it's the rarety of the original Deskpro 386 that limits it's reach? Great to see one of the follow up Compaq machines tho, and EISA is such a curio to.

Super stuff as always and hope you get the Tiger card to work. Cheers!

[patrickdube]

I was with you while powering it on... my god it did not blew!

[CosmoRiderDE]

Who else was like "wtf" when he went into C:\Unreal folder? I first thought he wanted to play that game.... haha

[firesurfer]

''In Compaq's Deskpro/M series -- the M stands for modular''
I'm guessing the heatsink pins were bent, causing a possible alarm to the previous owner thinking the power supply board may have been cracked.