Ozzuneoj wrote on 2023-04-06, 18:37:

Law212 wrote on 2023-04-06, 18:33:

Finished setting up my pentium 2 Voodoo 2 sli setup. […]
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Finished setting up my pentium 2 Voodoo 2 sli setup.

Im using a monster 2 8 meg card and a voodoo 2 12 meg card which isnt ideal but its all i have for now.

That SLI bridge PCB is pretty neat. I can't help but feel that one of the real 3dfx logos should have been used on it though. Where did you get it?

Looks like they're here - https://www.serdashop.com/3DVideoBridge

Iarsin wrote on 2023-04-07, 12:09:

I try to get some old MFM and rll hard drives running, but I never have done that before. So I'm not successful at all.

Don't be discouraged, those old drives literally die on their own from age. Adrian's digital basement did several videos on trying to revive some.

Got the video and sound card drivers and applications installed in my 1998 Dell Win98 system, and installed all the updates from the Windows Security 2004 CD. All that's left is to update the Live! drivers to the LiveWare 3.0 version, install the latest officially supported DirectX for Win98, and then it's time to install some games!

Me and a friend of mine wanted to play some Quake 2 coop so I used this moment to make some test:

• Tested Internet multiplayer on my retro PII build
  I set up a coop server on an AWS VM (the free one 😁) and invited my friend to play. He used a Mac with Yamagi source port and had no problem, while I experienced severe lag with my Pentium II build; I believe the bottleneck is the ISA ethernet card, which cannot keep up with modern clients speed.
  Overall we had fun 🙂
• Tested VGA capture
  Recorded my build VGA for the first time, through OBS: video was good while the audio was corrupted. Have to investigate the issue.

Uploaded a video of the test: https://youtu.be/OfdK-150bfs

I placed the Quake 2 OST over it for the audio recording problem.

Veeb0rg wrote on 2023-04-10, 04:26:

Iarsin wrote on 2023-04-07, 12:09:

I try to get some old MFM and rll hard drives running, but I never have done that before. So I'm not successful at all.

Don't be discouraged, those old drives literally die on their own from age. Adrian's digital basement did several videos on trying to revive some.

The motor shaft can also freeze if it's been stationary for too long. If it's accessible, you can try giving it some help.

What kind of oil is suitable? Can I use oil for sewing machines? Or WD-40?

Tested once okay, but I think it's way to slow? It also did some noise that sounds exceptionally slow for stepper and maybe also heads?
IMG_20230406_203318.jpg

The Unisys test Tool only counted read errors.
IMG_20230406_143915.jpg

Submit is greyed out when attaching files, I already noticed Saturday.

Therefore I'm also not able to send a Soundfile.

Kahenraz wrote:

HWiNFO for DOS provides a lot of hardware information.

None of the diagnostic tools will tell about the Mainboard. Therefor I actually think CPU-z will also not achieve that anyway.

The BIOS strings will tell Unisys pw² 500 16A, I guess.

Iarsin wrote on 2023-04-10, 10:00:

Kahenraz wrote:

HWiNFO for DOS provides a lot of hardware information.

None of the diagnostic tools will tell about the Mainboard. Therefor I actually think CPU-z will also not achieve that anyway.

The BIOS strings will tell Unisys pw² 500 16A, I guess.

I wonder how many 386-era motherboards had make and model info written in BIOS so a third-party software could read it out. 🙄

Finally finished my "Year2k" build based on PIII Coppermine 1GHz, Voodoo 5 and Aureal Vortex 2:

Very silent it is 😉.

It's based on a PC I had in 2001, with some changes:
* GeForce2MX -> 3dfx V5 5500
* SB Live! -> Aureal SQ2500

Case is actually the same.

There is no need to compromise. A PCI Sound Blaster can happily live alongside an Aureal Vortex. You just need to feed the line-out of one into the line-in of the other.

Getting the drivers configured is a bit tricky, though. Make sure to disable legacy sound emulation for one of them in Device Manager, otherwise they will conflict. Also install the Aureal drivers last or backup and restore the a3d.dll that is installed. Creative's version has bugs, and you need the Aureal one to work with the other card anyways.

Thanks. I will investigate.

It lives. 😀
Had to glue the case back together in a number of places, add a composite out mod and a PAL/NTSC converter, and also build a US-compatible power supply.
The cassette player/recorder is still busted.
But the "computer" part works fine.

stamasd wrote on 2023-04-10, 19:58:

It lives. :) Had to glue the case back together in a number of places, add a composite out mod and a PAL/NTSC converter, and als […]
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It lives. 😀
Had to glue the case back together in a number of places, add a composite out mod and a PAL/NTSC converter, and also build a US-compatible power supply.
The cassette player/recorder is still busted.
But the "computer" part works fine.

Good work!

The cassette deck will probably need a new belt, I had to do that on mine several years ago and was pretty much the only thing wrong with it. I hardly ever use cassettes though, a DivMMC expansion makes life much easier all around.

It's more than a belt; several of the buttons don't work properly, either can't be pressed down or when pressed don't click in place and stay down (the "play" button does that), so there's more to it.
It's not critical, I have a Interface 1bis to use with it https://sites.google.com/site/interface1bis/
and a TZXduino.

Depending on the mechanism, of it's some kind of carbon-backed switch or dome, you can repair these with a bit of special paint. 8-bit Guy did an episode on this for a different keyboard.

BTW I've used several "broke" cassette boomboxes as amps with merely a cassette/aux adapter, they don't need to turn, stop, eject well or anything else, all you need is some play mechanism function to get the head in place, even if you have to wedge the button down. So, it's possible you might get it "working" with one of those, with the 3.5mm plugged into another tape deck, MP3 player, winCE handheld (They play wav well) or laptop or desktop.

I've had a lot of trouble using much newer cassette decks with my ZX81. Recording is particularly difficult. It's much better to use a mono cable or adapter as well.

This was the advantage of the all-in-one units. No need to fiddle with an external tape deck.

Kahenraz wrote on 2023-04-11, 13:06:

Depending on the mechanism, of it's some kind of carbon-backed switch or dome, you can repair these with a bit of special paint. 8-bit Guy did an episode on this for a different keyboard.

It's not the computer keyboard. That works fine. It's the controls of the mechanism of the tape deck, you see those at the bottom right of the picture separate from the keyboard.
There's something that mechanically stops them from operating correctly. Probably some part broken inside.
I think this machine had some sort of mechanical shock applied to it at one point. All of the standoffs that hold the 2 halves of the case together were broken and the bottom part of the case was cracked. That may have damaged the mechanism of the tape deck as well.
At least the PCB was intact and it works correctly. And the keyboard, which would be a pain to replace.

(BTW the PCB is actually +2B rev.1 not +2A; it's part number Z70833 - in theory I could remove the tape mechanism altogether and replace it with an original disk unit, and it would work seamlessly)

Another thing to look at with these old mechanisms is the grease. They can turn to glue and hold the heads and pinch rollers down. This is what happened to my Nakamichi deck.

Thermalwrong wrote on 2023-04-01, 00:50:

At last I've sort-of managed to troubleshoot something using my oscilloscope. I posted a picture of this board the other day wit […]
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At last I've sort-of managed to troubleshoot something using my oscilloscope. I posted a picture of this board the other day with the front and back traces overlaid - I got this board a couple of years back as someone else had attempted to repair it and not got it working. I couldn't do much better although I did repair a bunch of the vias it still wouldn't do anything.

This is a WTC POP-3254 and the example shown on the retroweb appears to be in a worse state than my one. It's a rather old and basic 386dx board with no cache and the battery had destroyed some traces and vias by the 82c206 chip. It was coming out of reset and the clocks were working, but it didn't do anything.
Checking with the scope on the BIOS EEPROM I could see that there were signals on both the address and data lines, but some of the address lines seemed to have the same signal patterns and went from 5v to 2.5v which didn't seem right, most signals went to a lower voltage for a low signal.

Washed it up in the sink because this board has clearly been exposed to the elements and there were some white marks around most of the pins where I think the lead was leeching out. It cleaned up nicely but that didn't fix anything.
One of the 74LS373 chips had been replaced and socketed by the previous owner so I decided to pull everything in that area off, test it and check the connections of the traces, including the 82C206:
IMG_1156 (Custom).JPG
The pads/legs of the 82C206 were a bit corroded so that had to be checked too - there were bad VIAs hiding underneath it. Laboriously tracing and checking each trace that the 74LS373s attached to. The 74LS373 that wasn't replaced was bad after all, but its traces were in better shape.

WTC-POP-3254-tracing.jpg
A front and back picture lets me trace all the lines in Krita and see all the points they pop up - this is doable because this is a comparatively simple 4 layer board with VCC and GND on the inner layers, with signal routing on the outer layers only.
You can see how it looks for tracing here: Re: What retro activity did you get up to today?
This has the underside as the bottom layer with a filter mask layer to adjust the tint. The topside layer goes above that with the Blending Mode set to Lighten - which gives a really nice kind of overlay and the layers are different colours so it's easy to tell what I'm following. Some more layers on top with the set of pins I'm tracing. I'll definitely use this method again in future, I was able to find a bunch of broken connections by following the traces on the screen.
Then drawing a marking by the pin so I can tell it's been checked - only one wire had to be run on the outside, that's the one marked X.

Put it back together and put the 82C206 back on, it powered right up! Yay 😀
IMG_1159 (Custom).JPG
IMG_1158 (Medium).JPG
For some reason it has a 33MHz Intel 386, but the clock crystal is 50MHz for 25MHz CPU speed. The BIOS doesn't appear to be online and it came to me with no sticker on the EEPROM window, there was a big gap in the ROM file so I was worried the ROM was damaged, but it's fine after all. It's an AMI BIOS with a BIOS string of EOX3-6069-083090-KM
This thing is old enough that it has bios settings configured either with easy OPTI setup which has few options like wait state, or advanced OPTI setup where settings are configured by changing register bits, it's guided but it shows which bits are being altered for 11H, 14H etc. The board's from mid 1991 going by the chip markings but the BIOS and design both say '90, so it's probably the oldest computer I've got along with the Tandon motherboard.

edit: ergh okay so it's not working entirely. Stuff like keyboard works and I can change settings / save settings in the BIOS, but the computer can't boot from a floppy disk. Could that be a problem with DMA? That's handled by the 82C206 and there's a cluster of damaged traces there that were repaired.
It just says insert BOOT diskette and I've tried two known good drives, it does the track seek on boot so I think it's solely down to being unable to read the data.

As a follow up to this, I've been trying to figure out what's wrong with this POP-3254 / OPti 381/382 chipset 386 motherboard. The board posts, runs from a hard drive and can run programs, but it couldn't read floppies and PCM audio was coming out as a garbled mess in any test - that's a DMA problem. The 82C206 chip handles DMA and I fixed some traces that were broken underneath it as well as some of its traces that run over to the KBC - that's how it came back to functioning.
I could see that DMA was being processed like a DRQ was happening and there was a DACK following from what I could see but still garbled noise. I was getting ready to buy a new 82C206 and replace that but on a whim and following some traces from the 82C206 data pins, I pulled off the two 74F245 chips here, which from what I can tell connect it all to the bus - looks like they were in the path of the corrosion that this board was subjected to as the solder for them was tough to remove:

Both of them tested okay out of circuit but they had some dirt under them and the legs were pretty discoloured. I cleaned it all up a bit and put them back to get the board back to operational, again on a whim because I didn't think this would have fixed anything, tried a game and now sound works!

So now the DMA for both floppy and sound is working perfectly again and I don't really know what I fixed. Maybe the 2x 74F245 chips were used to make up 16 bits and one wasn't working because of dirt under the chips causing connections where there shouldn't be, causing the garbled-ness? But the lower one may have worked to allow everything else to function? I don't know enough about this stuff yet.

I'm really glad this is fixed since I was going to get an 82C206 but couldn't see how a board could be so otherwise functional with just some badness on the DMA. The more I use this thing I see it's a pretty odd board, the original BIOS was from like 1990 and would get angry if I installed 1MB SIMMs, limiting the board to 2MB of RAM. That was fixed by putting another board's BIOS on it - thank goodness for the retroweb's comprehensive search functions and BIOS repository: https://theretroweb.com/bios/?chipsetId=366
I put the 1991 BIOS from a Biostar MB-1325PD on it - and it works! Now the BIOS is the much more 'modern' green/purple/brown AMI BIOS I'm more familiar with.
Normally I wouldn't try random BIOS files but did you know that many of the Opti 381/382 chipset boards are essentially identical?

There must have been a reference design, these ones are all exactly the same down to the placement of the 74' logic chips and the RTC circuitry.

Tempted to borrow a crystal socket from another dead board along with its 66MHz crystal, the chipsets are marked as 25MHz but now I want to see if it can do 33MHz since this is a 386DX-33 chip.