Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

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Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby jade_angel » 2017-3-13 @ 20:05

I've been trying to get just the right video card for one of the machines I've been monkeying with over the last few weeks, and I've hit into something weird. The machine is a 486, with a Micronics JX30GC VLB/ISA motherboard. I have four cards I've been trying to get working with it - a Cirrus GD5428 1MB, a Tseng ET4000/W32 1MB and two GD5429s, both with 2MB. The board layout of all three Cirrus cards is exactly identical, except that the upgrade memory sockets on the 5429s are populated, while they're not on the 5428 (the sockets are there, but no chips are in them). But here's the thing: with either of the 5429s, I get no output whatsoever. With either of the others, the box starts right up, no questions asked, and runs like stink.

Unfortunately, the ET4000 doesn't have any memory upgrade sockets. I was hoping to be able to use one of the 5429s to get slightly better performance than the 5428 and still be able to run at 800x600x24 under OS/2 and Windows, but apparently the 5429s are either both borken, or else they just won't chooch in this board. Anyone ever seen that kind of thing, or know of a workaround? Or am I better off just pulling the memory upgrades out of one of the 5429s, sticking them in the 5428, and going with that?

Full system specs:

JX30GC motherboard
64MB (4x16MB) 60ns parity FPM RAM
Intel 486DX4/100 CPU @3x33MHz
Bus running at 33MHz
Onboard VLB IO controller with floppy, parallel, dual serial, dual EIDE
Video cards described above.
4GB CF card in ATA-CF adapter (Pri master)
40x24x20 ATA CD-RW (Sec master)
SMC 8416 10BaseT Ethernet NIC
ESS AudioDrive 1868F ISA sound card

EDIT: pic of a card identical to mine, all three look like this with the slight difference that the chip on the far left is not socketed on the 5428, and of course, the main graphics chip itself.
Image
Last edited by jade_angel on 2017-3-13 @ 22:35, edited 3 times in total.
Main Box: Ryzen-TR 1900X | GTX 1050/Radeon RX 580
98/2000 Box: PIII/866 | G400 MAX
PCI DOS Box: 5x86/133 | S3 Trio64/V2 PCI
VLB DOS box: 486DX4/100 | Cirrus GD5428 2MB
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Re: Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby kenrouholo » 2017-3-13 @ 20:22

It's been years since I touched a VLB system so I doubt I'll be much help, but I will help others help you by asking you to list the full hardware for the machine. What CPU in particular - and what bus speed is it? And if the bus speed is above your minimum, does lowering it help? Some cards can be picky. And do you have any other VLB cards - especially ones that can be temporarily removed, as well as any ISA cards you can temporarily remove? VLB can also be picky with more cards (any shared bus can, but VLB was one of the pickier ones).
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Re: Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby jade_angel » 2017-3-13 @ 20:46

Edited to add full specs. I could try pulling out some of the other ISA cards, maybe. Disconnecting the ATA devices doesn't seem to matter - same result, 5429s don't POST (and no beep codes), Tseng and 5428 work fine.

I would have guessed that my GD5429 card was just busted, but two of them are showing exactly the same symptoms (and still do when I take the RAM upgrades out of them).
Main Box: Ryzen-TR 1900X | GTX 1050/Radeon RX 580
98/2000 Box: PIII/866 | G400 MAX
PCI DOS Box: 5x86/133 | S3 Trio64/V2 PCI
VLB DOS box: 486DX4/100 | Cirrus GD5428 2MB
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Location: Virginia

Re: Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby jade_angel » 2017-3-13 @ 21:39

Just tried with all mass storage disconnected and the other ISA cards pulled, so only the onboard IO controller and the video card. Works with the GD5428, works with the ET4000/W32, no go with either of the 5429s. Just for giggles, I tried putting the BIOS chip from the 5428 on one of the 5429s - no dice. Then I put the BIOS chip from one 5429 on the 5428, and wouldn't you know, it came right up. Ain't *that* a kick in the head?
Main Box: Ryzen-TR 1900X | GTX 1050/Radeon RX 580
98/2000 Box: PIII/866 | G400 MAX
PCI DOS Box: 5x86/133 | S3 Trio64/V2 PCI
VLB DOS box: 486DX4/100 | Cirrus GD5428 2MB
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Re: Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby kenrouholo » 2017-3-13 @ 21:46

while you're at it see if you can try with bus speed at 25Mhz... probably won't work, 33MHz isn't too bad. If you said you had a 120MHz (40MHz bus) before, I might have some confidence in this solution, but hey worth a shot.
Yes, I always ramble this much.
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Re: Micronics JX30GC and Cirrus GD5429 VLB - doesn't chooch?

Postby jade_angel » 2017-3-13 @ 22:02

Just also tried it with 25MHz bus speed, and tried toggling both the other two bus switches (<33/>=33 and 0/1WS), and no dice.

Incidentally, with the bus speed set at 40MHz, the 5428 boots to DOS (but locks up in Doom and won't boot to OS/2), and the ET4000 gets partway through POST before exhibiting acute failure to chooch. This board is not at all keen on 40MHz. For yuks I tried throwing the upgrade RAM onto the 5428 card and it works (and the higher resolutions are available in OS/2; I didn't test to see if it was stable.)

The 5429 apparently has DMA support, I wonder if that's what's causing the problems? The BIOS on this board is surprisingly devoid of options, so there's not much I can tune there.
Main Box: Ryzen-TR 1900X | GTX 1050/Radeon RX 580
98/2000 Box: PIII/866 | G400 MAX
PCI DOS Box: 5x86/133 | S3 Trio64/V2 PCI
VLB DOS box: 486DX4/100 | Cirrus GD5428 2MB
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Posts: 354
Joined: 2017-1-03 @ 00:10
Location: Virginia


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