And what happens if you get it wrong?

D'oh. The clear-head of Morning Coffee tells me the "power good" signal is likely for POST. So if your PSU doesn't generate it, you'll simply get the AMI beep code for no power. If the multimeter says otherwise, swap the jumper to Internal.

Conversely if you've got it jumpered for Internal and your PSU does generate this signal... I'm not sure it'd do anything. But then that does beg the question Why have the jumper? If it doesn't matter, why not ship the board hardwired for Internal?

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EDIT: Did my reading. The Power Good signal tells the motherboard that the PSU has powered up and is ready to provide stable voltage. It can also cause a board to reset during brown-outs as the Power Good signal quits and then returns. It's +5v on Pin 1, and is the Orange wire.

Still dunno what would happen if you were jumpered for Internal while using a PSU with a Power Good signal. I'm happy enough to be able to confirm my kit has Power Good and am not inclined to try something that might let out The Smoke.

I once had a slot-1 board that refused to start, for reasons unknown. Maybe it was the power good signal, I really don't know. I believe that PSU worked with other boards though.
I forced it to run by jumpering the green wire to ground (if I remember the color correctly). It worked for a few short sessions over the next few months, then it stopped POSTing anymore. I don't know if my actions led to that outcome or not.

Good weather to clean a case.

Booted!

Oh, it looked so much better the first time I reassembled it. It just didn't boot in that state. Or even POST. So, many little adventures later I am very very pleased to see this box finally boot. I really thought it wasn't going to happen.

First game played: Grub Invaders, on the All In One Boot Disk Ver.1

One adventures that I still don't get, was i was getting the three-beep memory error code no matter what I populated the first two slots of Bank 0 with. After I populated the four slots of Bank 0 and Bank 1, the problem vanished.

Glad to see it works!

pewpewpew wrote:

One adventures that I still don't get, was i was getting the three-beep memory error code no matter what I populated the first two slots of Bank 0 with. After I populated the four slots of Bank 0 and Bank 1, the problem vanished.

These are 30-in SIMMs, right? Forgive me if I'm wrong, but it sounds like you were trying to install them in pairs. These need to be installed in quadruplets in systems with 32-bit memory bus. But you probably know that and I'm just making an ass of myself 😵

Looks like a nice 80486DX33 system. 😀

oerk wrote:

These are 30-in SIMMs, right? Forgive me if I'm wrong, but it sounds like you were trying to install them in pairs. These need to be installed in quadruplets in systems with 32-bit memory bus. But you probably know that and I'm just making an ass of myself 😵

Nope! I'm the ass here. My memory said 'old RAM is in pairs', which seemed to be backed up by the table on th99. So a compound-failure on my part.

How should I read this table?

EDIT: D'oh! I did it again -- it's 4 slots per bank, not two. This chart shows four banks because it covers the two banks on the board, and two more banks in an optional expansion card.

Okay so it's a little unreasonable to run Knoppix on a Trident TVGA 8900C, but it proved I finally got a good CD drive correctly hitched up /and/ that the serial mouse works. Hence I'm very pleased. Also It booted Knoppix in not much more than an hour.

FIN.

That was great fun. I've basically got a nice 486DX33 from the leftovers that didn't make it to recycling.

Turns out the Asus ISA-486 disables cache for Turbo.

PC-relative speed - CPU=4807% FPU=5003%
PC-relative speed - CPU=1448% FPU=1800%

Time for those was 100 and 34 seconds... so yup, I'm very pleased to say, 'This box goes to 11.'

3DBENCH FPS 17.2
doom -nosound -timedemo demo3 FPS 10.4

The no-name IDE-Floppy controller and I/O card are pretty nasty but seem to work fine. Fit is terrible. Have to use a loose slot-shield on one and carved some material off the tongue of the other.

External battery is a modern button-cell in a holder looted from an unworthy P4.

Video is TVGA 8900C because that turned out to be the only ISA I have.

Audio is speaker. I can borrow the SB Pro2 from another box as needed.

CDROM is a decidedly non-period 32x that supports CDRW. It auto-detects fine with W98 Startup and FreeDos, but not W95 Startup.

HDD is a Caviar 2635 640MB that makes a pleasing amount of sound without being noisy.

A tiny failure is I have not found the button for the Reset switch. Since I was surprised to find the rest of the original switches, I've rummaged my boxes of Stuff quite thoroughly for the Reset. Perhaps it will show up underneath or behind something yet.