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Dual Pentium EISA SBC (Diversified Technology ESP3520)

Given that EISA cards generally require special configuration in the EISA setup utility to work, I would second using a regular ISA video card that will work without any special configuration being required.
 
There are cards with edge connectors which physically match those of EISA cards, which are not EISA cards. The OPTI Local Bus is one example. Several PC integrators used an EISA connector on a motherboard to carry ISA/VLB or ISA/PCI signals to a mezzanine board (the so-called "slot riser board") even though there were no EISA signals involved anywhere. It wouldn't surprise me to learn there were SBC integrators who did similar things with their passive backplanes.

In this case, though, the SBC uses the 430NX chipset which allows for EISA, and actually includes a PCI/EISA bridge (the 82375) and system component (82374). So we can be reasonably confident it is indeed intended for use with actual EISA slots, and not just to plug in to an "EISA" slot.

...ok, well, now that I looked close enough to read the chips, the "Phoenix EISA BIOS" sticker is also a pretty good indication. sheesh!
 
GiGaBiTe said:
Given that EISA cards generally require special configuration in the EISA setup utility to work, I would second using a regular ISA video card that will work without any special configuration being required.
Click to expand...
The Compaq QVision (1024/E, 1280/E) are the only ones I've run into that don't work at all until configured. The VGA core of the Mach32 EISA will work fine without the board being configured. The VGA core on the Spectrum/24 EISA (if so equipped) is only connected to the ISA bus anyway, so it also works. I can't speak from experience about any other EISA "base" video boards.
 
Hmmm. The card I have is a QVision 1280/E. I'm going to try it in my other EISA system to ensure that it works. How do you configure it if it does not work until configuring?

I may pick up an ISA video card as well, however I would have expected a different behavior than I am seeing after trying to boot with no video card.
 
Not seen a standard EISA backplane. Not seen this card.

Back in the good-old-days some video cards followed the MCA base VGA/addon graphics. The addon e.g. 8514/A, did not handle VGA graphics, on MCA the VGA is passed to the addon card via the slot. There were some ISA and possibly EISA cards that work like this too, and as such don't have any actual VGA circuitry. They were designed to work with a standard VGA adapter. I don't have a QVision 1280/E, but from Bear's description. it sounds like an annoying one that acts like this even though it can do VGA too. If it can it probably will work in a Compaq, it was designed for. Compaq often did weird things, perhaps a non-standard BIOS routine to wake it up. Or it's just broken. Second getting a VGA adapter/known working EISA/VGA adapter.

Sometimes it's hard to work out what the post codes mean when they say "check for errors" and "clear boot flag". Don't neglect the PC speaker output. May tell you more. Does it flash other codes first, or get stuck there very early? Any difference between codes with or without the backplane?
 
Thanks so much for a that Starcat! I don't know how you found that manual. I spent a lot of time on dtims.com with wayback, but clearly missed it.

I believe I have the proper backplane:
2025-05-20 21.24.58.jpg

I ordered a PC speaker and ISA VGA card so will try that next
I could not get this Compaq 1280 to work in my Compaq EISA system - I wonder if any of them are alpha firmware?
 
legodude said:
Hmmm. The card I have is a QVision 1280/E. I'm going to try it in my other EISA system to ensure that it works. How do you configure it if it does not work until configuring?

I may pick up an ISA video card as well, however I would have expected a different behavior than I am seeing after trying to boot with no video card.
Click to expand...
You run the ECU with an ISA video board to insert the QVision into the configuration, save, power off, then install the card. This is what Compaq telephone support told me to do in the early '90s when I tried upgrading my (non-Compaq) 486 from a CL-GD5422 (ISA) to a QVision 1280/E and ran into this, and it is what I ended up having to do.

Compaqs have a dedicated slot that is supposed to enable the QVision even if it's not configured (marked on the back with a little CRT icon), presumably with support from the BIOS. I recently tested this for the first time, with a QV1280/E in a Deskpro 5/60M, and did not have that experience, so YMMV there.
 
legodude said:
I wonder if any of them are alpha firmware?
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If a PC VGA card is supported on the Alpha, it's directly supported. The Alpha SRM and AlphaBIOS both emulate x86 instructions on the Alpha for the purpose of executing VGA BIOS extension ROM code.
 
bear said:
If a PC VGA card is supported on the Alpha, it's directly supported. The Alpha SRM and AlphaBIOS both emulate x86 instructions on the Alpha for the purpose of executing VGA BIOS extension ROM code.
Click to expand...

I knew this at one point in time and completely forgot, thanks for the reminder. What a wild system.
 
ISA video card came in and we have progress:
2025-05-31 20.05.53.jpg

2025-05-31 20.08.00.jpg

Thanks to all who suggested an ISA video card.
How much will the missing EISA configuration file cause trouble? I assume this file is lost forever, is it possible to adapt a file from a similar system (same chipset etc)?
Are the configuration utilities pretty universal?
 
legodude said:
How much will the missing EISA configuration file cause trouble? I assume this file is lost forever, is it possible to adapt a file from a similar system (same chipset etc)?
Are the configuration utilities pretty universal?
Click to expand...

The ECU itself is relatively universal. The .CFG files have been collected, but obscure ones are still troublesome to find. I couldn't say which category the one you'll need for your SBC will be in. Some system boards also want an .OVL to provide some extra functionality above and beyond the basic EISA configuration. Try it. See how far you get. If nothing else you'll have a set of better-targeted questions.
 
You may have some luck with this file as it has the same chipset

think this is the latest ecu/scu

get a dos boot disk, copy the ecu to it. You have to use the ecu to copy the file to a disk, (it creates a database file) Otherwise the ecu wont see the file when it detects the card. Before copying the file, run the ecu and it will tell you what file it is looking for. If you cant find the file with the correct name, try renaming the file in the first link.
 
legodude said:
How much will the missing EISA configuration file cause trouble? I assume this file is lost forever, is it possible to adapt a file from a similar system (same chipset etc)?
Click to expand...

Just like MCA, without the configuration files, EISA cards are effectively useless bricks.

But even if you can't get EISA working, not all hope is lost. You can still use the EISA backplane as a slower ISA backplane. It'd be like having one of those really early Socket 4 Pentium systems that had all ISA slots.
 
Thanks all for the hints. Mr Slug, I started with that file and modified a few things. I can now "configure" the system board part of my system with the AMI utility in the sense that it does not error out and writes something to NVRAM. During the initial configuration, it aksed for two additional files "!PPI5000.cfg" and "!ETI0000.cfg", both with slot "unknown." But since then, it has not asked for those files. The EISA2 utility only shows the SBC and my SCSI card (which I have the cfg file for).

So now it boots without the "Please run EISA config" message, but it does complain about the ram size being set incorrectly (I set it to 64mb in the ECU).

I guess my next step is to try and get the Compaq EISA video and network cards to work, then see if I can load an OS.

I've started to poke around in some of the EISA utilities and docs. Is there a way to go from card -> de novo config file, or is it all just guesswork?
How much can I wedge the system if my handcrafted "!DTI3520.CFG" contains errors, but it still lets me write to NVRAM?
 
legodude said:
I've started to poke around in some of the EISA utilities and docs. Is there a way to go from card -> de novo config file, or is it all just guesswork?
How much can I wedge the system if my handcrafted "!DTI3520.CFG" contains errors, but it still lets me write to NVRAM?
Click to expand...
I suppose it depends on the error, but IME if the CFG file contains, say, a syntax error, the ECU will reject it. If your CFG is syntactically correct but writes the wrong configuration registers, then I guess your card will not be configured correctly. I don't know from experience, but I don't imagine that would prevent you from rewriting them some other way later. Without knowledge of how the board makes use of its configuration registers, I doubt you will be able to usefully write a config file from scratch. Having an empty file might let the ECU write a valid configuration that it won't complain about, but I wouldn't then expect any of the cards to be configured in any predictable way. Some of them might give you "default" configurations, but absolutely not all. I'd want to be extremely cautious trying to do this for a system board, where a bad configuration might well result in an inability to run the ECU again. One possible hedge against that is to dump the EISA NVRAM in its current state, so that, in case of catastrophe, it can be externally reprogrammed with known-good contents.
 
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For the "RAM size incorrect", hopefully you don't have any bad memory. Some systems have the ability to automatically mask off memory areas they determine are bad, and will sometimes report a lower maximum memory. It's not a very common feature in x86 land outside workstations and servers, but this is a then high end weird backplane SBC, so anything is possible.

You could try running an older version of Memtest. I'm not sure if the last "old" branch of Memtest will run on a Pentium, which was 5.31b. Avoid 4.20 because it was compiled incorrectly and some tests will generate false positives. I believe it was test #4 and #7 that had problems.

There's also the possibility you have a FDIV bugged Pentium. The Pentium 90 was bugged before mask revision B5. CPU World helpfully has a list of known mask revisions for that particular CPU, so you could figure out what you have.

I don't think Memtest uses FPU code, but I could be wrong. If it does, you're going to have problems.
 
bear said:
I suppose it depends on the error, but IME if the CFG file contains, say, a syntax error, the ECU will reject it. If your CFG is syntactically correct but writes the wrong configuration registers, then I guess your card will not be configured correctly. I don't know from experience, but I don't imagine that would prevent you from rewriting them some other way later. Without knowledge of how the board makes use of its configuration registers, I doubt you will be able to usefully write a config file from scratch. Having an empty file might let the ECU write a valid configuration that it won't complain about, but I wouldn't then expect any of the cards to be configured in any predictable way. Some of them might give you "default" configurations, but absolutely not all. I'd want to be extremely cautious trying to do this for a system board, where a bad configuration might well result in an inability to run the ECU again. One possible hedge against that is to dump the EISA NVRAM in its current state, so that, in case of catastrophe, it can be externally reprogrammed with known-good contents.
Click to expand...

Yup, starting from the file suggest by Mr Slug, I had to edit it until I got fixed the syntax errors (I removed references to PCI in the slot definitions for example). The file is much less complex than I thought it would be.
I think it might be helpful to find a detailed motherboard manual and its config file and compare the two to see if I can gain some insight that way.
Backing up the NVRAM is a darn good idea. I should have done that first. It still has the correct time.
 
Shadowlord had a go at writing a cfg file. he sent me this:
Perhaps you've already found it.

Every board i've found with the 430NX EISA chipset has PCI slots. There's this https://theretroweb.com/motherboards/s/ami-titan-ii-s711#docs

Has 8 slots, but I'm sure you have sorted this already. The cfg file though has an ovl file, complicating matters. I think that eisa spec book explains how to make them, but I think it's compiled code. Here:

Though I don't think that helps you much.

tried hitting their website, but no cigar

Wayback Machine

web.archive.org web.archive.org
 
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