Help me bring back retro 80386 test system to 2016! - Page 1
Forum section: electronics / projects

author: MrMetthew
author_rank: Regular Contributor
timestamp: November 29, 2016, 02:41:24 pm
content: Hey all,I have a problem maybe you guys can help with. The place I am currently working at has an old test setup running on an old pc from the early nineties. They asked me if I could replace the system with a new one as the old one is getting pretty old,, and they're fearing a fatal crash one of these days. I agree with them that it is probably time to replace this machine, or at least provide them with a back up system.The system is used for legacy testing and calibrating of spare parts they produce. And contains hundreds of test executables dating back from God knows when. The system runs a 33MHz AMD Am386DX/DXL-33 processor from 1991. So a real 80386 in the flesh. There are also multiple ISA slots on the motherboard in which there are at least 4 different (crucial) custom in-house made cards for interfacing with the different test setups. The system runs DOS6.22, the last official DOS.I looked for modern replacement machines which have ISA slots on the motherboard, as it is crucial they can keep on using the cards for legacy testing/calibrating. My eye fell on the following machine:http://www.duropc.com/products/isa-slot-computer/rac033-1.html#tabs-1However there is ONE catch :p. The test implemented on the old 80386 processor need the slow 33MHz clock speed of the current processor. Yes, you read that correctly, the code needs a low enough clock speed. Turns out that the "slowness" of the test naturally induces wait times for for example rising voltages on the bus of the custom cards connected to the various products under test. And unfortunately I don't think you can under-clock these new processor to speeds of 33MHz (please do correct me if I am wrong on this one).Has anyone an idea on how to move this test system too a more modern pc? It is not feasible to rewrite the tests or to reimplement them in any way as there are hundreds of them most poorly documented if documented at all.So in short the system should run DOS 6.22, have atleast 4 ISA bus slots and should run at 33MHz.Thanks for the help guys as this is not my area of expertise, I am just working on this as a side project and really could use the help of some of you retro computing efficianados !

author: Ian.M
author_rank: Super Contributor
timestamp: November 29, 2016, 03:02:34 pm
content: Run Run away as fast as you can, and start polishing your CV!If the parts this system tests are more than 1/3 of the company's revenue stream, there are better than even odds of the company going under when it fails. Even throwing shed loads of money at a brand new ATE system wont help if the tests cant be recreated quickly enough to meet contractual obligations.The key problems are:* Custom ISA interface cards (I assume no spares and insufficient documentation to recreate them)* >20 year old ISA bus PC* Missing documentation* processor speed dependent codeEven attempting to get a backup of the drive could be the final straw that breaks the camel's back and as the last 'tech' to touch it you *WILL* get blamed for *ANYTHING* that goes wrong.Its basically unsupportable - if there are spare cards and enough documentation to repair them it might be worth trying to source a 486 era motherboard, getting it fully re-capped and building up a spare PC using a solid state drive (e.g a CF card in a CF to IDE adaptor).With the cache disabled and if you clock it down you *may* be able to get it to run the cards OK, but then you would have to re-qualify all the tests which you don't have proper documentation for.

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: November 29, 2016, 03:12:30 pm
content: +1 for Ian.M's comment above. I too would get the hell outta there as fast as I could.It is going to be a nightmare trying to find a suitable system to replace what you currently have. Another possibility, however, is try and find an used 80386 motherboard + cpu that are in better condition than yours. Or maybe just replace some caps, keep it clean and hope it will run for another quarter of a century.If I were in your shoes, I'd start looking for used parts in fleaBay, surplus stores, and so on.

author: CJay
author_rank: Super Contributor
timestamp: November 29, 2016, 03:14:15 pm
content: Ha, Ian.M beat me to it, run away, fast.It's undocumented, running 20+ year old code, hardware etc.It will be a nightmare and has potential to make your life a living hell unless it's incredibly simple.I find it difficult to believe they've not got full test specs of the product they produce though, how do they verify the test rig is still working correctly?

author: kxenos
author_rank: Frequent Contributor
timestamp: November 29, 2016, 03:31:14 pm
content: Messing with old and closed hardware/software is a nightmare I had to deal with because I run systems with windows 3.11 with proprietary ISA cards and floppy disks and ASICs and the likes, and I couldn't agree more with Ian.AFAIK there are industrial PCs with ISA slots but I don't think you will find one with 4 slots and anyway I don't think you will be able to underclock it that much. Finding old PCs maybe is the cheapest and easiest solution but IMO this is a job for a custom FPGA board. Google found these guyshttp://www.rtd.com/PC104/DM/digital%20IO/FPGA6800.htmTheir prices seem reasonable.

author: grumpydoc
author_rank: Super Contributor
timestamp: November 29, 2016, 03:44:54 pm
content: Ah, got distracted by work while typing a response only to come back and find I'd been beaten to it.Having nothing to do with this is by far the best option.The correct way is to start again with modern hardware and to re-specify the tests and softwareand get it properly documented this time.If you really have no option (and I strongly urge you to consider emigration or pleas of insanity first) then look on ebay for 386 motherboards/ATA drives, ideally new old stock rather than used. Get several identical ones and build some back-up systems.But really, run away screaming.

author: CJay
author_rank: Super Contributor
timestamp: November 29, 2016, 03:52:23 pm
content: Quote from: grumpydoc on November 29, 2016, 03:44:54 pmHell no, run away very quickly but quietly, if they hear you go there's a good chance they'll give chase and catch you.

author: LaserSteve
author_rank: Super Contributor
timestamp: November 29, 2016, 03:59:49 pm
content: Considering it took me two months to find an old machine around here with a full length ISA slot, in working order, RUN AWAY NOW.I worked for a computer recycler/reseller during the ISA era to get through college. The Chinese voraciously gobbled up dead machines for scrap back then. We shipped full size shipping containers of PCs, dead or alive, mostly disassembled, overseas. They paid very good money for the scrap.That depleted the stock of old computers in the US, in un-imaginable ways. What is left is dead or dying of old age.I keep a bunch of DOS and WIN 3.1 Systems running for my employer, and I assure you a 33 Mhz system will be rarer then a hen's tooth.Anything left from that era will be timing out from shelf life issues, and a easy way to kill a computer is to NOT use it.You can find industrial 486/586s made to this day for CNC machine replacement. If you can't run in that environment, your looking at a complete redesign as others have said.Steve

author: grumpydoc
author_rank: Super Contributor
timestamp: November 29, 2016, 04:07:33 pm
content: Quote from: LaserSteve on November 29, 2016, 03:59:49 pmThere's a current listing on fleabay for 10x 386DX-33 motherboards so they can be had.The bigger issue is the very real chance of killing the existing system by disturbing it enough to e.g clone the hard drive.

author: Ian.M
author_rank: Super Contributor
timestamp: November 29, 2016, 04:10:16 pm
content: It doesn't make any sense to buy NOS DOS era ATA (IDE) drives. 20 year old spinning rust is just too unreliable even if its been on the shelf all that time.DOS 6.22 has a 2GB partition size limit, so CF cards in a CF to IDE adaptor are the way to go - sub 8GB CF cards are very affordable. The big issue will be BIOS limitations the BIOS Int 13 8.5 GB limit prevents DOS accessing more than that, and if you are unlucky the BIOS will have a limit under that (e.g the infamous 1024 cylinders, 16 heads, 63 sectors/track, 528MB limit for non-translating BIOSes).Your best bet for getting the data off the system non-invasively would be parallel Laplink or Interlink to something old enough to be DOS bootable but new enough to have ATA drives that can be read on a modern system using a USB ATA adapter.

author: chris_leyson
author_rank: Super Contributor
timestamp: November 29, 2016, 04:19:30 pm
content: My employers still have a few old 386/486 test systems with custom ISA cards but they will probably get dumped in a few years rather than replaced. You can buy PCI to ISA adapter boards and NIXSYS make mother boards with up to 3 full length ISA slots but not sure if you can run at 33MHz.

author: grumpydoc
author_rank: Super Contributor
timestamp: November 29, 2016, 04:30:23 pm
content: Quote from: Ian.M on November 29, 2016, 04:10:16 pmYes, thinking about it that would be preferable.But the more I do think about it the more it just generally seems like a bad idea.

author: edpalmer42
author_rank: Super Contributor
timestamp: November 29, 2016, 04:38:00 pm
content: Regarding the speed issue, I have vague memories of slowdown utilities that basically sucked up enough CPU cycles that the system seemed to be running at a lower clock speed. This made old games playable on a 'fast' 486 system.Once or twice, I disassembled programs to find and change software timing loops to make them work on a faster system.It can be done, but it's a long, tedious process.

author: CJay
author_rank: Super Contributor
timestamp: November 29, 2016, 04:49:44 pm
content: Turning off cache was a major step forward in having timing critical software run on 'faster' systems, it's usually possible to underclock systems too but all bets are off when it comes to AMD/Intel chips.There were enough nasty little bugs in those chips that software that's stable on one might fall over in a very nasty way on the other.Advice still stands, run away.

author: Ian.M
author_rank: Super Contributor
timestamp: November 29, 2016, 05:23:58 pm
content: I certainly wouldn't touch the project with a bargepole unless ihere were enough spare cards etc. to make it possible to set up a replacement without taking the original offline or doing anything more invasive than inspecting the interface cards in-situ with a dentist's mirror to determine jumper configuration. You absolutely SHOULD NOT disturb any internal cables or remove any board or drive unless you have it in writing that your entire management chain understands that any work on the machine may result in its failure beyond any possibility of repair.

author: Zero999
author_rank: Super Contributor
timestamp: November 29, 2016, 06:37:57 pm
content: Quote from: edpalmer42 on November 29, 2016, 04:38:00 pmYes, there's Throttle which doesn't actually burn up cycles but uses the power saving mode to under clock the motherboard. It won't work on really old motherboards though.http://www.oldskool.org/pc/throttle/DOSThe OP could also look into replacing M$ DOS with FreeDOS, which is compatible with most DOS programs and is much better.http://www.freedos.org/

author: guido
author_rank: Regular Contributor
timestamp: November 29, 2016, 06:47:10 pm
content: I use slowdos on a P3 to keep an old programmer working. And i also have a 486 system around aswellI would try to get some more machines. You can still find them. And make a backup of the HD.Then you have the old cards left as a risk. Suggest to back anything on there that can be dumped (eproms/pals etc).

author: CraigHB
author_rank: Regular Contributor
timestamp: November 29, 2016, 07:15:51 pm
content: Pretty amazing a manufacturer can build and maintain a test rig with no design documentation whatsoever. That is some seriously bad management there. A normal company would modernize the rig from the ground up based on original design data, but that can't be done. A company that negligent kind of deserves what will inevitably happen under such poor process management. They'll have to build that system from the ground up the way they did in the first place, hopefully with the proper documentation next time. If the system fails under your watch you're helpless to repair it and you'll take all the blame for their screw up. So like everyone has said already don't touch it.

author: amyk
author_rank: Super Contributor
timestamp: November 30, 2016, 03:58:34 am
content: I still have a 386 desktop (only 25MHz though) that works. If anything I'd say components back then were far less likely to be engineered for planned obolescence, and the speeds and tolerances involved mean you have a better chance of fixing it than a more recent PC.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 30, 2016, 07:01:32 am
content: The worst thing to do now is to panic and try to get some parts replaced, because that would not increase the reliability much (you still have the issues with custom undocumented old HW and SW), but you'd lose time and money doing that.The only sensible option is to respecify the needs and redo it fully with modern components. This includes redoing all of the tasks those custom ISA cards are doing. It's very likely that, properly specified and designed, the complexity will decrease by an order of magnitude - way fewer moving parts.Why replace one part of a big system, when you can get rid of the whole ordeal?If the system has been running fine for decades, there is no need to panic; it will most probably continue running for a while. So, you have ample time to properly design the new system NOW, because now you don't need emergency fixes.If this is not possible for any reason, I think the second easiest thing to do is to try to exactly replicate the system. This means getting a similar old 386 PC, and making copies of those custom HW cards. The old PC may not be reliable for a long time, but if it's running the tests OK, it will still be a working spare machine in case the current one goes out of service.

author: IanJ
author_rank: Unknown
timestamp: November 30, 2016, 07:17:46 am
content: Run away?......does nobody like a challenge........Bring on the project and get stuck in if you are confident enough.....but FIRST get written assurances that you will not be responsible if it all goes wrong, let management take the risk, not you.The first thing I would be doing is plenty documentation, photos and notes that you can muster, speak to people and find out if the PC is shutdown at all (if it's 24/7 will it restart?), any spares at all?......then clone the drive.One other option is to replicate the system (new or used parts will do) so the existing HDD (image) will stand a better chance of booting. Different chipsets can stop the OS booting.Ian.

author: CJay
author_rank: Super Contributor
timestamp: November 30, 2016, 08:01:02 am
content: There are challenges and there's certain death.Personally my approach would be to try and re-engineer the test procedure, knowing what 'parts' the machine tests, knowing the test/fail parameters, building up a new test rig and testing that is far preferable to even touching the old rig, right now I'd be very concerned that the old rig is passing faulty parts if nobody knows those parameters.Guarantees that you won't be held responsible for failures are one thing, having people stick to them and not be jumping up and down on your head when your production line is down is quite another, people hold grudges, especially if your insistence on written guarantees drops them in the sticky stuff.

author: Ian.M
author_rank: Super Contributor
timestamp: November 30, 2016, 08:27:57 am
content: As I said up-thread, if there are sufficient spares of the custom cards to duplicate the system, its a much better proposition, which has a far lower probability of the O.P. being backstabbed by management as the original system can be handed back to production in working order while he works on the replacement.A 386 era PC is likely to have pre-ATA hard drives, maybe early IDE, (incompatible with modern controllers or USB adaptors), or SCSI-I, ESDI or ST-506. Attempting to image the drive is a high risk operation if the imaging system's controller is incompatible with the drive. Finding imaging software that will run in-situ on a 386 era system, will boot from floppy (probably 5 1/4") and supports some sort of parallel port storage device will be difficult. (The system is unlikely to have Ethernet and even if it does, finding compatible drivers for the imaging software is unlikely)Its running DOS. The odds are fairly high that a simple filesystem copy using Laplink or Interlink over the parallel port would run OK on compatible hardware (motherboard and graphics card) provided it was made to a bootable drive of the same DOS version and MSDOS.SYS and IO.SYS are not overwritten. Of course, cloning a large filesystem over the parallel port is f£%^^£g slow, so its the sort of thing you start at 8AM and hope its done by 6PM. I've done a few similar jobs and soon learnt not to start them after lunch!

author: edpalmer42
author_rank: Super Contributor
timestamp: November 30, 2016, 05:21:52 pm
content: It might be useful to print out this thread and show it to management. That would show that it's not just you who's worried about the system crashing and burning the first time you touch it.

author: MosherIV
author_rank: Super Contributor
timestamp: November 30, 2016, 05:34:31 pm
content: HiI agree with Ian.MQuoteI work part time at the National Museum of Computing in UK and maintaining old systems is perfectly feasible if you keep a stock of spares. In your situation, I would do as Ian suggests - built a second (and a third) spare machine where you can just pull the ISA cards out and put them into the next. There are a number of sources for old computers like that : ebay, WEEE equipment re-cyclers, your own web siteGood Luck

author: voidptr
author_rank: Contributor
timestamp: November 30, 2016, 06:02:33 pm
content: Everything has been said ^^^Except that I might have one in my closet museumI booted up my first Pc 8088 8MHz last summer, It booted right away, those were so expensive, but those green characters are still prettyYou might find some 80386 in good condition around.

author: IconicPCB
author_rank: Super Contributor
timestamp: November 30, 2016, 08:06:00 pm
content: Let me add to the everything.Talk to your local industrial computer supplier.Inform Yourself about PICMG 1.0 backplane boards and various plug in processor cards. You may find a board with the required number of ISA slots and You may find a processor card runing a 33 MHz 80386 CPU.All the other caveats apply... ESTABLISH A PAPER TRAIL unless you want to be the bunny.

author: MrMetthew
author_rank: Regular Contributor
timestamp: December 02, 2016, 10:16:18 am
content: Thanks for all the feedback guys! We are currently reviewing what we are going to do. Btw there are indeed replacement cards. The machine is also only used for legacy tests and for the production of still supported spare parts, but none the less still generates some revenue. First thing what we are going to do is to calculate how much revenue the thing actually generates. Possible solutions than range from stopping support for the specific parts the machine is responsible for, testing and calibrating a certain stock of parts while the machine is still functioning and then retiring it. Or rebuilding the tests that are still profitable on a new platform (my personal favorite is an fpga/ARM SOC + labview interface). Again thanks for the advice, we now really realized how unsupportable this platform actually is !

author: CJay
author_rank: Super Contributor
timestamp: December 02, 2016, 10:56:49 am
content: Sadly, the right decision.As a technical challenge it is very interesting indeed and I'd have thoroughly enjoyed being given that sort of task but from a business/career point of view, it was a nightmare.

author: pelule
author_rank: Frequent Contributor
timestamp: December 02, 2016, 12:11:54 pm
content: Thanks MosherIV, I am feeling not such crazy anymore.My GPIB based lab-pc is an old ISA slot PC OS is Windows-XP (old HP system, thus not such old at the 386 AT's).All my new PCs failed after some years. This PC is running very well 24h a day, 7 days a week without any issues since 1997.I backup all data regulary, as I am not such crazy.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 02, 2016, 02:18:43 pm
content: Quote from: grumpydoc on November 29, 2016, 03:44:54 pmThere is no such thing as "correct" or "inccorrect", only more or less appropriate for a given situation.In this situation, if you can find/build of drop-in replacements for all parts of the system as backups this would seem by far the cheapest & easiest soluiton, without the risks of breaking something in the process of re-doing everything from scratch.It ain't broke - just get some backups for when it does need fixing.

author: Ian.M
author_rank: Super Contributor
timestamp: December 02, 2016, 06:08:55 pm
content: Quote from: mikeselectricstuff on December 02, 2016, 02:18:43 pm+1.Spares of the custom cards exist. I suspect a 486 board clocked down to 33MHz with Cache disabled will have near enough compatible timings, if not, then try to source a 386 board. Once its up and running off a CF card SSD, and all tests have been validated, run the new system for a month, obtain another identical motherboard and build up a spare the same way, then the old system can be retired.It also seems that management realises they've been running on pure luck for the last decade so the risk of the project going toxic is much lower. If the parts it tests still generate enough profit, or customer loyalty to justify keeping them in production, its worth doing.

author: Fungus
author_rank: Super Contributor
timestamp: December 02, 2016, 08:20:00 pm
content: Quote from: CJay on November 30, 2016, 08:01:02 amYep. Trying to replace the PC is suicide. Replicate the functionality/results instead.eg. All those ISA cards can probably be replaced with a few Arduinos.

author: timb
author_rank: Super Contributor
timestamp: December 02, 2016, 11:58:57 pm
content: Quote from: Ian.M on November 30, 2016, 08:27:57 amFirst off, ATA *is* IDE, they are synonymous. Basically, IDE was renamed to ATA (AT/Attachment) when the ATA-1 standard was ratified in 1994."Early IDE" drives are perfectly compatible with modern controllers, why wouldn't they be? So long as you've got a PATA port (or SATA to PATA adapter) it should work...I've actually got one of the *first* models of IDE drives to be produced; it came out of a Compaq Portable III (which was the first commercial machine to use the IDE interface). I can plug this 30 year old drive into a USB to PATA/SATA dongle and read the contents just fine...Anyway, by the time the 386 was popular (let's say 1990), IDE had pretty much become the defacto standard. SCSI was the only other real competition, however it was expensive so relegated to servers and high end workstations. ESDI was very short lived, being displaced by IDE. ST-506 was pretty much only used for legacy applications by this point as well.

author: Ian.M
author_rank: Super Contributor
timestamp: December 03, 2016, 12:22:05 am
content: I have a couple of 8 bit IDE drives that pre-date the ATA standardisation that definitely aren't compatible with modern controllers. One is a 40MB WD drive on a hardcard in a legacy system I've owned since the late '80's and the other is IIRC a 30MB drive I keep as a spare for the legacy system. Seehttps://en.wikipedia.org/wiki/Industry_Standard_Architecture#XT-IDE

author: westfw
author_rank: Super Contributor
timestamp: December 03, 2016, 12:28:57 am
content: QuoteYou probably mean the old MFM disks, complete with separate controller card.QuoteThat would be time better spent, especially if you document carefully as you go along.QuoteGeneric PC with a set of Arduinos to replace the custom logic. (You haven't mentioned what the custom cards DO, or how complicated they are, but we've established that Speed Is Not An Issue, so FPGA is probably overkill. And FPGAs "go stale" at about the same speed as PCs.)

author: kfnight
author_rank: Regular Contributor
timestamp: December 03, 2016, 12:50:25 am
content: At the Tektronix service depot they had a test system that was an 8086 running MS-DOS 3.2. Its software was programmed in QuickBASIC and was still going strong in 2008.

author: Ian.M
author_rank: Super Contributor
timestamp: December 03, 2016, 01:03:14 am
content: Quote from: westfw on December 03, 2016, 12:28:57 amNo I don't. I mentioned the possibility of ST-506 MFM drives, then there's ST-412 RLL, which looks like ST-506, but uses a different controller and could increase the data capacity of a drive by 50% over MFM, and I also mentioned ESDI. That's three different incompatible systems over the same type of cabling. Even if it has IDE, if its a generic PC, its almost certain to have a separate controller card - usually an IDE/FDC/IO combo card. The leading brand systems (e.g. Dell, Compaq) tended to have a higher level of integration and tended to have controllers on the motherboard.Then you get all the different drive geometries. Its one big can of incompatibility worms, hence my recommendation to use Laplink or Interlnk to get the data off.

author: timb
author_rank: Super Contributor
timestamp: December 03, 2016, 02:55:34 am
content: Quote from: Ian.M on December 03, 2016, 12:22:05 amThe hardcard doesn't count, because it's mounted on an ISA card, so it's not really IDE (well it is, but not in the traditional sense).As far as I know, there were no 8-bit only IDE drives (aside from CF); there was an 8-bit transfer mode that was part of the IDE standard. Basically, you'd install an XT-IDE card into your XT machine. It contained a BIOS and IDE connector and would talk to a standard IDE drive in 8-bit transfer mode.In fact, there's a modern project called XTide that has an open source BIOS available for XT and AT machines that provides large drive support, LBA and lots of other goodies. There are even several open hardware ISA cards, some with IDE connectors and some with CF connectors (plus ROM slot). I actually used the AT version earlier this year to get a 2GB CF drive working on an old 286. I just popped the BIOS into the option ROM slot of an EtherLink III card and it just worked. It's pretty slick.A friend used it to get a circa 1999 4GB hard drive drive going on an original PC XT. That drive was ATA-2, but it supported 8-bit transfer mode, so it worked fine.Edit: Despite what that Wiki article says, "XT-IDE" does *not* pre-date IDE. It came after, as a way to use IDE disks (that supported 8-bit transfers) with an XT class machine. The original IDE interface was first launched on a 286 (the Compaq Portable III) in 1986.Furthermore, even if you had a drive that only supported 8-bit transfers, it should still work today, as that's a mode required by CF cards, which are IDE by nature.

author: Ian.M
author_rank: Super Contributor
timestamp: December 03, 2016, 08:28:01 am
content: Seehttp://nerdlypleasures.blogspot.co.uk/2014/04/the-original-8-bit-ide-interface.htmlAlso the XT-IDE drive WD93044-X-11R I have in the legacy system is pre-1990, and the ATA-1 standard was ratified in 1994 (ANSI X3.221-1994, AT Attachment Interface for Disk Drives).I certainly had problems attempting to clone the drive on a more modern PC circa 2000, (I needed an image for an emulator) and in the end had to resort to copying the filesystem over a proprietary 100Kbps LAN to the HW emulator.

author: timb
author_rank: Super Contributor
timestamp: December 03, 2016, 12:25:25 pm
content: Quote from: Ian.M on December 03, 2016, 08:28:01 amYeah, and I've got an original 20MB IDE drive from 1986 that I just plugged into a USB to SATA/PATA adapter and was able to read the data off just fine.Just because the ATA standard wasn't ratified until 1994 doesn't mean that IDE as a standard wasn't followed from 1986 up to that point. It was.Anyway, XTA != XT-IDE.XT-IDE was basically putting regular IDE (ATA) drives into 8-bit transfer mode so they could work on the 8-bit XT bus. Most ATA drives of the era supported that, as do pretty much all CF cards. This was done with an XT-IDE ISA card that had a regular IDE connector and a special BIOS.XTA was a short lived standard that used different wiring, addressing and only used 8-bit transfers (except one drive that supported 8/16-bit).That WD drive is XTA, not XT-IDE.

author: ebclr
author_rank: Super Contributor
timestamp: December 05, 2016, 04:02:43 am
content: Possible solutionhttp://www.ebay.com/itm/HM386SX-Intel-386SX-25MHz-8MB-SIMM-Video-512KB-ISA-I-O-CABLES-WORKING-/282261294074?hash=item41b8158bfa:g:IEIAAOSwV0RXssfA

author: CJay
author_rank: Super Contributor
timestamp: December 05, 2016, 11:03:21 am
content: Quote from: timb on December 03, 2016, 02:55:34 amI'm pretty sure there were some 8 bit only XT IDE drives, they were pretty rare but they were used in Commodore A590 external hard disk modules for one, horrible slow stepper motor driven heads as well.I certainly remember searching high and low for the mythical hard disk drives which supported both modes but never managed to find any and eventually settled on buying SCSI drives instead after discovering a (very) cheap source of Maxtor XT4380S drives (old ICL mainframes and ICL/Fujitsu PC servers).

author: Fungus
author_rank: Super Contributor
timestamp: December 05, 2016, 11:30:19 am
content: Quote from: ebclr on December 05, 2016, 04:02:43 amI dunno. What state will the capacitors be in on a motherboard that old?Edit: I take that back. Looking at the photos, there aren't any electrolytic capacitors on that motherboard.

author: Fungus
author_rank: Super Contributor
timestamp: December 05, 2016, 11:40:48 am
content: PS: Embedded 386 machines are still a thing, you can actually buy new ones...https://encrypted.google.com/search?q=embedded+386+system+with+isa

author: ebclr
author_rank: Super Contributor
timestamp: December 06, 2016, 06:37:13 am
content: For IDE driveshttp://www.ebay.com/itm/Super-Talent-DuraDrive-ET3-64GB-2-5-inch-IDE-Solid-State-Drive-MLC-/321695435495

author: timb
author_rank: Super Contributor
timestamp: December 06, 2016, 11:40:35 am
content: Quote from: ebclr on December 06, 2016, 06:37:13 amThat's massive overkill, especially when a 512MB-2GB CF card would work just as well and you won't run into any LBA issues.

author: technix
author_rank: Super Contributor
timestamp: December 06, 2016, 01:22:14 pm
content: If you can still find the original specs for the test signals, try rewrite the test suite moving it to a microcontroller. I think that a PIC18F4550 @ 48MHz or STM32F103RC @ 72MHz have enough horsepower to replace that aging system testing the DUT. Those USB microcontrollers also allow you to use a modern laptop to diagnose the target system.