Rescuing a REMARKABLE 386 DX-25 Made by Compaq

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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:
ftp.zx.net.nz/pub/archive/ftp...
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.

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Опубликовано:

11 фев 2023

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Комментарии : 112

@ultrametric9317 Год назад

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.

@pipschannel1222 Год назад

He's using a 16-bit ISA videocard so I doubt that in case of the Unreal demo the EISA bus has anything to do with the performance difference between the two machines shown in this video. The performance difference between the 386SX and the 386DX is not because of the EISA vs. the ISA bus. It's because of the DX having 32-bit memory bandwidth while on the SX the CPU breathes through a 16-bit straw while accessing the memory, which is why a 386DX-25 is typically more than 3 times as fast in terms of DRAM throughput compared to a 386SX-16.. (3.125 times faster to be exact, difference in clock speed included, cache excluded). SX machines (which were entry level machines) were really hampered by this obvious bottleneck compared to DX machines in the 386-class CPUs. I.E. my 1988 Deskpro 386/25 (an original first generation Deskpro like the 8086 and 80286 models which has only ISA slots) is also way faster than any i386SX class machine out there in terms of DRAM access which is what one would expect from a high-end 16000 dollar machine back in the day ;-) This thing also features an Intel 80385 with 32k of SRAM (cache) which makes its memory even faster..

@wishusknight3009 Год назад

It has 16k external cpu cache. That will be doing a lot of heavy lifting. And its a zero wait state machine. In this video, the EISA did bupkis for it.

@chateuaxfaygeaux Год назад

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.

@damouze Год назад

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.

@PCRetroTech Год назад

That could well be the case. I didn't check at all what it was doing in addition to palette cycling.

@pipschannel1222 Год назад

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!

@PCRetroTech Год назад

Ah, fantastic to have information about the mysterious M. Do you happen to know the meaning of the E and N? Also great info on the hard drive.

@pipschannel1222 Год назад

@@PCRetroTech The only one I'm really certain of is the /M(odular) moniker which was the high end workstation after the SystemPro and it was the ancestor of the Deskpro XL, which were all pretty expensive to produce and had a very high price tag as well.. These were the top of the bill EISA machines/workstations/servers(the latter being the SystemPro's purpose as the very first dedicated x86 PC server and ancestor to the Proliant which still lives to this day as an HP machine of course ;-) ); The rest still kept using 16-bit ISA.. In fact I have a 1995 Deskpro XE560 (Pentium class machine) which still used ISA only with on board local bus graphics! Come to think of it I don't think Compaq ever used any VESA local bus slots on their Deskpro machines. They stuck to EISA, which was their own invention. They went straight from ISA to PCI on the lower end models like their Presarios.. Don't pin me down on the following as I'm not 100% sure I remember right: The /N(etworking) were the pizzabox models, small and simple. Sort of a thin client if you will, just like IBM did on their PS/2 line (the networking models without any local storage and just a NIC and a bootrom).. The /I(ntegrated) models were slightly newer and bigger than the N with IO/32-bit Compaq QVision video etc. integrated on the mainbord and a simple ISA riser card; These were the higher end machines and were released next to the first Prolineas (the newer entry level moniker). The /E(xtend(ed)/xpand(ed)) (not really sure) was slightly more expandable than the /I with its 4 vertical full size ISA cards and a prorietary 32-bit RAM card (no riser).. Compaq seemed to produce boatloads of different Deskpro (and very similar Prolinea) models at the time which makes it kind of hard to keep track of all of them ;-)

@pipschannel1222 Год назад

@@PCRetroTech As a sidenote; If you're planning to upgrade this beauty: You can get a pretty nice increase in graphics performance over a regular 16-bit ISA card if you can find the original videocard for this machine which is called the QVGA, a 32-bit EISA card which was specially made for the video slot in this machine!

@PCRetroTech Год назад

@@pipschannel1222 Thanks. I hadn't even heard of the /I models, but this all makes sense. I wonder if this was actually a good marketing strategy of Compaq. It must have been confusing for consumers.

@pipschannel1222 Год назад

@@PCRetroTech Yeah good marketing strategies kind of evaporated when Rod Canion, one of Compaq's founders and spiritual father was fired as their CEO in 1991.. Things kind of went downhill after him leaving and for a lot of people (including yours truely) the company kind of lost its soul.. I own a lot of Compaq machines but my favourites are from the first 10 years (1982 to 1992).. They produced a lot of brilliant hardware during that era!

@scargo02 Год назад

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.

@scargo02 Год назад

Here's a great video by Compaq from 1991 on the DeskPro /M family: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-sKLRCmARqok.html

@PCRetroTech Год назад

Thanks for all the extra information. It's starting to become clearer now. Compaq must have had quite a few markets they wanted to cover. Regarding an EISA NIC, I'm not much of a networking buff, but thanks for the offer anyway.

@PCRetroTech Год назад

@@scargo02 Fantastic, I'll check it out. I wish I'd seen that before making this video!

@pjaro77 22 дня назад

I'd like to see this EISA "Advanced VGA" card.

@joshhiner729 Год назад

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.

@PaulinesPastimes Год назад

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. 😊

@HighwayHunkie Год назад

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

@PCRetroTech Год назад

Ha ha!

@sebastianbort8512 Год назад

Im looking for q3a folder 😂

@osgeld Год назад

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

@BrassicGamer Год назад

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!

@PCRetroTech Год назад

Yes, it's a really special machine.

@paulstubbs7678 Год назад

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.

@PCRetroTech Год назад

You might be right about the monitor base, I hadn't noticed that. Yes, I think Compaq really put a lot of work into their design. This one doesn't have the built in Compaq video, but it still seems really quick in other ways to me.

@borlibaer Год назад

Congratulations🎉👍 how lucky You are 🥳

@patrickdube6716 Год назад

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

@MM. Год назад

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.

@PCRetroTech Год назад

I agree that they are a beautiful machine. I think Amstrad is another company that really put work into making the design look beautiful.

@mogwaay Год назад

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!

@PCRetroTech Год назад

I've never seen one of those CPU cards come up. It was truly a miraculous find. I did try Superscape and it was glacially slow. Even the version designed for slow machines just took too long to run so I didn't even let it go through once. I agree on the Compaq being highly underrated. The original Deskpro is just super rare, whereas there are enough IBMs out there for many people to own them. I'm not even sure why that is. Somehow I guess people hung on to the IBMs for posterity. The Compaqs probably got bought mainly by businesses and just disposed of (though who knows how many there are out there in storerooms).

@CPUGalaxy Год назад

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.

@PCRetroTech Год назад

That'd be an interesting thing to look at given the comments here. Some commenters believe this machine would really fly with an EISA card. Others say the good ISA cards ended up being better. Still others say that it depends on the FSB (which I can believe).

@firesurfer Год назад

''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.

@PCRetroTech Год назад

Interesting.

@john_ace Год назад

The perfect match would be a Compaq "Q-Vision" or "Advanced VGA" EISA card. These cards are very rare at the moment but quite fast.

@PCRetroTech Год назад

Thanks for the suggestion.

@rallyscoot Год назад

Very nice channel to follow.

@PCRetroTech Год назад

Thanks and welcome

@highpath4776 Год назад

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

@benjaminrondeau3148 Год назад

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.

@PCRetroTech Год назад

That would be an interesting test. I've seen people claim a 20MHz machine is so well timed for the RAM that cache makes almost no difference. RAM access is pretty much 2 cycles, which couldn't really be improved. The slowdown with the SX was the 16 bit data bus, so it wouldn't be a fair comparison. But a DX without a cache would be interesting to compare.

@benjaminrondeau3148 Год назад

@@PCRetroTech For slower parts you're absolutely right however Intel made 25 and 33 MHz versions of these cache controllers and they weren't cheap so they must be worth something. I happen to have a cacheless 386DX-33 system if you want me to run some tests so we can compare.

@PCRetroTech Год назад

@@benjaminrondeau3148 It might be a bit difficult to rule out other architectural differences. The best would probably be if I figure out how to disable the cache on mine.

@benjaminrondeau3148 9 месяцев назад

Turns out that in the meantime I acquired a PGA-132 MB with an i395 on it (Fountain Technologies FTN 386DX-33C) so I was able to run some tests. I averaged the score of 14 different synthetic benchmarks (the usual suspects…) to compare the performance with the i395 enabled and disabled. For a combo i386DX-33/i387 the gain was 23% and for a RapidCAD the gain was 34%. Further research into the 82395DX datasheet revealed that it contains 16 KB of 4 way set associative cache with pseudo LRU algorithm that supports Intel486-like burst transfers and FPU decode logic. Using a fully software transparent dual bus, a bus master device can access the system bus simultaneously while the i386 reads from cache on the local bus (assuming a hit) at near zero wait state. It also includes a write buffer which allows for continued operations without having to wait for write cycles to update the memory with a TAG for every 16 bytes, so this sounds like the same thing as the integrated cache of a 486. Combine the presence of this chip and the EISA bus in the Deskpro M and you start to see why it was the flagship workstation.@@PCRetroTech

@PCRetroTech 9 месяцев назад

@@benjaminrondeau3148 Very interesting. That's actually a bit more than I was expecting. On the other hand, a 386DX-33 is going to be pretty bottlenecked by memory access if it runs at a speed almost exactly matching a 20MHz machine, nearly half the speed. So maybe it's not that surprising.

@AlexCruise Год назад

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!

@PCRetroTech Год назад

I always thought these machines with backplanes or dumb motherboards like this were too proprietary to be useful. And indeed this machine sat in my basement for ages until by pure luck I found the card I needed. Now I really like the machine. You can take that CPU card out and just upgrade to a 486 or even Pentium Overdrive just by plugging in the appropriate card. I haven''t seen a lot of Turbo XT clones like this, so your machine must have been slightly rare.

@AlexCruise Год назад

@@PCRetroTech Mine was a Samsung SPC3000, I don't know offhand if it could've accomodated a 286 "brain transplant" or if one was ever manufactured... I replaced it with an Am386DX-40 machine with 4MB RAM, Trident 8900C, 105MB HD and 14" SVGA monitor that cost $1748 CAD in 1991. :)

@PP-xy9bg Год назад

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 :)

@PCRetroTech Год назад

Sorry about that. People complained about the way I read the numbers in the past, so I now say Eighty-Three-Eighty-Six. Oh well.

@PP-xy9bg Год назад

Really, no need to apologise for that. I shared that as curious fact about how I had a mental block to analyse the words (as a non native English speaker). And thank you for continuing making videos after your move.

@heyitszim6359 Год назад

Are my eyes deceiving me, or did you edit your video to resemble a documentary show from the 90s? If yes, then I'm really impressed.

@PCRetroTech Год назад

It's an unconscious format that has evolved, but I'll take the compliment.

@Dinnye01 Год назад

Damn, good to be first :) My first PC was a 486 and I have seen 386s disassembled... and always was curious of the differences as a (4 year old) kid. This has so much nostalgia factor for me that you could not imagine.

@PCRetroTech Год назад

Glad you enjoyed the video. There wasn't a huge amount of difference in how they looked inside to be honest.

@Alcochaser Год назад

Your the second person to do a video on this machine. Look up a video by Rik's Random Retro. "Compaq DeskPro 386/25M - The Modular Fun Machine" The memory card just added SIMM slots you had to populate with SIMMs. His also had the original EISA video card. Well if you want to bother. The original card for this machine was a slug, and EISA didn't do much for video anyway. Most ISA cards would outrun the original anyway. The original EISA card also used a weird VGA connector with pins missing that may or may not work with the monitor you have.

@pjaro77 22 дня назад

Flex architecture - compaq was first who divided pc common bus to system and external (ISA, EISA, etc) by bus bridge. Then every manufacturer copied this in 386 ant newer machines.

@RowanHawkins Год назад

Anytime you add a card you'll need to go into the BIOS to tell the BIOS what the card is. If the card is an EISA card there will be an extra driver disk. It is possible to load those utilities into a diagnostic partition for doing the BIOS changes but I don't remember if that was only the later generation systems that supported the Pentium Pro that I worked on.

@ToTheGAMES Год назад

Why are your videos compressed so much? I noticed this since you have moved, I think.

@PCRetroTech Год назад

I imagine it's RU-vid. I haven't changed my process. Some of the VGA recording has to be done at lower resolution because of technical limitations to do with 70Hz refresh rate on the monitor, but all the rest should look exactly the way it did before unless RU-vid is screwing with it.

@HighwayHunkie Год назад

Oh you were located in Germany before? Been following your channel since a while. Great videos, well explained. I got a Compaq 33Mhz DX Tower here with a bad power supply. Cant test it. If i knew you lived in Germany, would have shipped it to you to look after it because my skills are not really good at soldering. Anyways, interesting, nice video again, awesome special machine. Could you maybe pls upload this "Unreal" Demo" to Archive org? Greetings from Germany.

@PCRetroTech Год назад

Yeah I was in Germany. The Compaq tower might be one of their fancy machines that they introduced not long after the one in this video. The Unreal Demo is available on Pouet, one of the central resources for all Demo stuff. Just look for the group Future Crew and you'll find it there.

@HighwayHunkie Год назад

@@PCRetroTech damn, theres many nice demos of all times and platforms. Didnt know of that. Thanks for telling me.

@tomiluukkonen4035 Год назад

Sadly EISA-bus machines (and cards!) were ridiculously expensive, not targeted for small businesses or home users :( About 386DX vs. 386SX - 32-bit memory bus helped a LOT, especially combined with decently speedy VGA-card. 386SX's halved memory-bus killed performance from the start and most cheap 386SX-machines had no external cache in motherboard. Even little 64kb cache in MB made a huge difference and pricier 386DX-ones almost always had some. Combine that with 32-bit memory bus and demos actually ran as advertised. Been there since 80's, I used 386-class machines in late 80's and early 90's. With decent 386DX+MB, next one to tune was VGA-card... how you pumped up bus timings and card itself. Have you tried overclocking older Cirrus or S3-cards? Good old times!

@PCRetroTech Год назад

I've done quite a bit of overclocking of VGA card on VLB and ISA machines. Yes, I agree the 32 bit bus helped a lot. That is one of the main points of the video of course, although I could have made that clearer by mentioning it in the conclusion at the end rather than just alluding to it in the introduction.

@tomiluukkonen4035 Год назад

@@PCRetroTech It could be interesting to see how much overclocking actually helped in 90's? IF I remember correctly I got up to 20% more out of my Cirrus 542x/543x- and S3-cards back then. Used VGASPEED and some other early "benchmarks". And in many cases it actually improved gaming experience in DOS-era games years before 3D-cards. And thanks about interesting video as always, keep up the good work!

@ruthlessadmin Год назад

3:22 - Please never throw anything away, no matter the state! I'll gladly pay you to ship it to me (unless it's totally smashed, then maybe not). I am short on everything, especially AT cases, ribbon cables, serial/parallel headers, spare-parts boards/cards, and PSUs... I have at least half a dozen machines worth of retro hardware with nothing to build them in, on top of at least another half dozen that just needs a piece or part here and there to be complete. Recently I bought some ATX blank-off I/O shields, with the idea to punch holes in them to make AT-to-ATX adapters but it's certainly not ideal to build these old machines in sleek, modern cases lol

@PCRetroTech Год назад

I threw away 9 machines when I moved. I did everything to find people to take them. Not a single person turned up. Shipping just wasn't possible due to the fact I was already working around the clock. I barely made it to the train when I left Germany and took about a month to recover from exhaustion.

@ruthlessadmin Год назад

@@PCRetroTech hehe..yeah, we briefly talked about it before in the comments of another video. I was very sad, but I understand. I hadn't even found your channel yet, or I would have certainly done what I could to help.

@Nephiaust Год назад

I'm pretty sure the M in the model is for Micro Channel. It looks like a MCA system...... (I could be wrong, never got to play with MCA)

@ultrametric9317 Год назад

Warning, if you do buy EISA cards for this machine, remember at least some of them are inoperable without the corresponding option disk to set the board parameters in conjunction with the COMPAQ setup disk. Jumper free didn't yet mean plug and play!

@PCRetroTech Год назад

Yeah I saw all this in the setup program, which I have.

@brianbuchholtz1521 Год назад

EISA can be such a PITA to configure. Even with the correct setup utility and config files, there's no guarantee the card will be compatible with the motherboard. But for the era, EISA was quite good. Just wish better video cards were made for the standard. Not all EISA motherboards have VLB...

@wskinnyodden Год назад

By the way, it should not be hard to make a memory board for that slot with just the pinout of the slot, that will be FPM RAM for sure so pretty easy stuff to implement.

@PCRetroTech Год назад

Yes, that would be an interesting project, and certainly something I thought about. I don't know the pinout at the moment though. Documentation is really sparse.

@wskinnyodden Год назад

Oh and by the way, if you want to run Demos like Unreal, Second Reality (this one in particular) make sure you completely avoid ANY SLC model, not one has worked for me on those without crashing at some point, some times a bit later into the demo (1 scene if it worked) but it would crash nonetheless. Moved to a 386SX40 from an SLC40 and guess what, no more crashes.

@PCRetroTech Год назад

Interesting. I wonder what the problem is with those?

@HighwayHunkie Год назад

@@PCRetroTech maybe misconfigured CPU settings somehow? Possible?

@wskinnyodden Год назад

This EISA System should have the RAM maxed out, the CPU maxed out (so a AMD 40Mhz if you want to keep true to the 386, or an DLC or SLC model but please keep the 40Mhz FSB), a decent 387 FPU added and then dumpster dive as deep as needed to find EISA cards, like for example a Creative Sound Blaster (oh wait, was that an MCA one... not sure) Network EISA card is mandatory and those should actually be not that hard to find (by comparison), a SCSI Controller and CD Burner why not, a TV Tuner card with composite input (as TV RF will not work nowadays in most scenarios), and any other EISA card you can fathom! The main goal is to demonstrate how you can manage DMA, IRQs etc in a easier way than moving jumpers around :) (etc)

@PCRetroTech Год назад

As the case has 25m written on it I want to keep it as a 25 MHz 386, but I would like to try an EISA card in it eventually, for sure.

@fradd182 Год назад

Honestly, soon as you said that its not a graphics card, i knew it was a CPU board.

@PCRetroTech Год назад

I'm too predictable aren't I. 🙂

@fradd182 Год назад

@@PCRetroTech Haha, not really. it just happened that i have recently watched an episode of Computer Chronicles where they showed a system like that, with CPU upgrade card, so i knew what to expect.

@PCRetroTech Год назад

@@fradd182 Ah I see!

@douro20 Год назад

The original Deskpro 386 was a very expensive machine to begin with; I believe it was actually the most expensive offering Compaq had made to date. It's too bad HPE took the entire Compaq progeny with them...

@PCRetroTech Год назад

I think the 386 was unaffordable for most for a pretty long time. The SX changed that for many people, but it wasn't really until the AMD DX chip that the original 386 came into the hands of the average punter. But a lot of such machines were poorly executed. It's really nice to have one that was executed so well (proprietary connectors notwithstanding).

@Ice_Karma Год назад

25:30 For whatever it may be worth, US$3,999 and $5,699 in 1991, adjusted for inflation, would be $8,930 and $12,726 in 2023.

@heilong108 Год назад

could you please add a link to the setup utility in the description? I just bought one of these :)

@PCRetroTech Год назад

Unfortunately there is no obviously reliable site to download these. The best I came up with was: 66.113.161.23/~mR_Slug/pub/EISA/sources/COMPAQ/added%20to%20archive/ However, you need to know which one to download. Too early (or possibly too late) and it won't work. In my case I used sp0842.exe.

@heilong108 Год назад

@@PCRetroTech sure that's the one? You mentioned 4 floppies being required in the video but that archive only makes 2 disks. And they are 1.2MB not 1.44

@PCRetroTech Год назад

My apologies, it's sp6144 that you want [1]. I originally looked through my downloads folder and the other softpaq was the only one I found. But I just checked my USB stick and found it was actually the later one that I used. I still don't know how I got it onto my USB stick without actually downloading it. I must have partially cleared my download history or something. Anyway I'm pretty confident sp6144 is the right one. [1] ftp.zx.net.nz/pub/archive/ftp.compaq.com/pub/softpaq/sp6001-6500/

@heilong108 Год назад

@@PCRetroTech that's it! Got my system configured. You're right these are quite fast

@PCRetroTech Год назад

@@heilong108 Great that you were able to get yours going. I've been spending time writing code on mine. I realised that cache barely affects a 386 DX until you get to about 20 or 25 MHz because the bus and CPU are almost perfectly matched at 25Mhz if you have 80ns RAM, which this does. But I believe it has a cache anyway.

@wskinnyodden Год назад

Your VGA may actually be an EISA model, which would make it faster. Can you check this?

@PCRetroTech Год назад

I wondered this myself, but the connector looks like ISA to me. I don't think it is a EISA card.

@pipschannel1222 Год назад

@@PCRetroTech You can easily spot the difference between them. An EISA has twice the ammount of connections ISA has.. Most of the difference in speed between the SX and the DX is caused by a vast difference in memory bandwidth as the DX has full 32-bit 25MHz memory whereas the SX has 16-bit memory bandwidth and is running at 16MHz, making the DX's DRAM throughput more than 3 times faster!

@PCRetroTech Год назад

@@pipschannel1222 Yes, that is what I would expect.

@Pickle136 Год назад

was there a difference in L2 cache?

@PCRetroTech Год назад

I believe so, yes. Compaq mentioned the cache in their advertising. I don't have comparative figures though.

@Pickle136 Год назад

@@PCRetroTech l mean was there a difference L2 cache between your two 386 pc's to help explain the difference in performance?

@PCRetroTech Год назад

@@Pickle136 Yes, that's what I'm referring to. I believe the cache on their later machines was superior. One of the other really big differences is the 32 bit bus obviously.

@8bitbubsy Год назад

There's no L2 cache on 386 systems, since there's no L1 cache inside the 386 CPU itself. Also, it was very common for 386 systems to not even have external L1 cache (no cache at all).

@Neksus-M06 Год назад

I had one of those Compaq, we threw everything away :( The keyboard was heavy. All was heavy.

@PCRetroTech Год назад

Yeah they sure are heavy boxes. You can't take it everywhere. I also threw stuff out back in the day that I regret now.

@wskinnyodden Год назад

You considered throwing away an EISA BASED BOTHERBOARD! I would be ashamed, very very ashamed!

@PCRetroTech Год назад

It was purchased as not working and I had to throw a lot of stuff away when I moved. I had someone say they wanted this machine and that they would come and collect it. They never turned up. At that point I'd already finalised my customs list and I was utterly exhausted. I had very little choice in the end. I saved it only because I found that CPU card online and decided to dispose of a different machine instead.