I replaced 1MB of DIPP memory with 4MB of SIPP memory in my 286.

I had been looking for 4MB of SIPP memory and came across it a few weeks back for not to expensive of a price, so I grabbed it. Not much software for a 286 makes use of it but its cool nonetheless to have it installed. 😀

Some info about the set up for those interested, the board is a run of the mill 286 but it is in really good condition, the battery was literally pulled off by the looks of it (I still need to clean that up). It has an ET4000 based video card and an original Sound Blaster 2.0 with CM/S. It probably my favourite machine as I like to program graphics and sound stuff in assembly language specifically for the 286.

In the last photo you see the case it is in. It's a low profile case and I managed to get two of them at the time, new old stock. As you can see in the line-up, I use a "slide in, slide out" system where when I want to tinker with a machine I slide it out and hook it up. When done (or weekend is over) I unhook and slide it back it it's place. It's pretty good system as I used to have a KVM system, waaaaay to many cables etc.

Against the wall, from front to back there is a 386DX-40 based system (same low profile case) with a Cirrus Logic VGA and a Sound Blaster Pro 2, next a 386SX-20 based system Trident VGA and PAS16, then a 486DX-100 with an S3 VGA/PCI (but can run VLB as well), a GUS and SB16 VT1740. Finally a case for what is going to be a Pentium based system (TBD).

Pictures or it didn't happen...

I recently re-entered the world of CRTs after probably a 20 year absence. So, using my recently acquired 17" ViewSonic I noticed quite a noisy signal. I immediately suspected my VGA KVM of uncertain qualiity, but no that wasn't it. Then I feared the monitor is just dying. And then I remembered to think about EMI, looked behind the monitor and saw my cable modem basically leaning against the side of the monitor. Doh!

I tryed my new SSD on my MacBook but , after installing OS X 10.8 (lion?) , I was unable to update to 10.10 Yosemety , then found I need to change the date back to 2014 so I did that , started update to 10.10 but It froze at about 30% , I don't know what to do? let it sit a few more hours or reboot and start update again? Is it a ram problem?(not enough?)
would stoping a frozen installation(30% or so) , ruin the OS X 10.8? also? It's eating me to much time so.... I am puzzled.

L.E. I rebooted , it Reloaded , setup continued.

Tried to get some more life signs from my HP Vectra XU 5/90 today.. not much to report unfortunately.

Signs of life!

I would say its orange and yellow. Not mentioned in the manuals that I have found so far.

The cpu gets warm
Chips on the motherboard gets warm
Keyboard blinks at start
Soft power on/off works most of the time.

I have tested with one and two known good Pentium 133 and two sticks of FPM memory, also tested and working.

Any ideas 😀

IIRC multi pentium boards could be fussy about exact S spec and having a matching pair of same.

BitWrangler wrote on 2023-06-08, 22:15:

IIRC multi pentium boards could be fussy about exact S spec and having a matching pair of same.

Both are the same stepping, SY022 so I don't think that its the problem. I get the same behavior with one and two CPUs.

Some years ago, my boss at work threw away a little 8" LCD tv from Maplins, which I kept. It could take VGA but looked terrible doing it with awkward scaling, but it had a 640 x 480 LCD in it, so I threw away the TV and kept the LCD.

Some months ago I made this PCB for the 44-pin LCD connector that you can find on many industrial PCs and single board computers. Initially I thought it was advantech specific but it seems to be standard across many of the Taiwanese integrators that were making x86 SBCs.

The LCD that I took out of that 8" LCD TV uses a 32-pin flat flex cable with I think 0.5mm pitch pin spacing that's way too small for me to solder, thus this PCB was necessary and it's worked for several other LCD panels but not this little Sharp 8" LCD and I had no idea why. It's been on my 'please fix this at some point' pile for a long time.
It would work with this board but it would show noise on any details on the screen like in the BIOS screen the red & white text would have some break-up here and there. In Windows any details like the start menu were illegible and when doing the Shut down Windows screen which does the cross-hatch thing, the display would just break entirely on displaying that.
Initially I thought it was down to the BIOS on this Advantech PCA6145 and other SBCs that had wrong details to drive this LCD panel since the LCD worked with its original board and the digital picture frame driver boards, where I'd sourced other 640x480 TFT LCDs from digital picture frames. I'm upcycling them 😀

Going through it all on the oscilloscope looking at signals I noticed that the picture frame boards did drive the screen at a higher frequency and was trying to figure out if there's a way to make the SBC's BIOS match this, but I couldn't see a way to do that. Then I had a read of yyzkevin's experiences with getting a VGA LCD working with custom wiring: https://www.yyzkevin.com/clock-signal/
I am so glad this information is shared, the frequences matched up to what my SBC was putting out at ~25mhz so maybe there's no way to change the frequency. Also the amplitude of my clock signal was all wrong, 8 volts peak to peak?

I found that my SBC doesn't implement any filtering on the motherboard for the LCD signals so my PCB should have been doing that. To fix that I cut the trace for the clock signal and started bodging on new parts, to match up what the Chips & Tech CT65550 datasheet specifies for filtering. 220pf capacitor and initially I tried resistors in line, that was bad.

But then I stole this blue filter thing from a scrap PCB's USB data lines and tested again, now the display is 100% working! I need to figure out what this part is called so I can get a fixed PCB version eventually 😀
The clock signal looks cleaner on the scope, the display is great now, it even handles the cross-hatch in the Windows shutdown screen, pixel perfect. All it was was just how 'clean' the clock signal is when there are ~20 other signals in total.

This means I can start making something to hold this screen and an SBC at last.

Thanks Kevin for sharing your experiences with LCD troubleshooting 😀

Thermalwrong wrote on 2023-06-09, 01:21:

Some years ago, my boss at work threw away a little 8" LCD tv from Maplins, which I kept. It could take VGA but looked terrible […]
Show full quote

Some years ago, my boss at work threw away a little 8" LCD tv from Maplins, which I kept. It could take VGA but looked terrible doing it with awkward scaling, but it had a 640 x 480 LCD in it, so I threw away the TV and kept the LCD.

Some months ago I made this PCB for the 44-pin LCD connector that you can find on many industrial PCs and single board computers. Initially I thought it was advantech specific but it seems to be standard across many of the Taiwanese integrators that were making x86 SBCs.
advantech-pca-6145-lcd.jpg
The LCD that I took out of that 8" LCD TV uses a 32-pin flat flex cable with I think 0.5mm pitch pin spacing that's way too small for me to solder, thus this PCB was necessary and it's worked for several other LCD panels but not this little Sharp 8" LCD and I had no idea why. It's been on my 'please fix this at some point' pile for a long time.
It would work with this board but it would show noise on any details on the screen like in the BIOS screen the red & white text would have some break-up here and there. In Windows any details like the start menu were illegible and when doing the Shut down Windows screen which does the cross-hatch thing, the display would just break entirely on displaying that.
Initially I thought it was down to the BIOS on this Advantech PCA6145 and other SBCs that had wrong details to drive this LCD panel since the LCD worked with its original board and the digital picture frame driver boards, where I'd sourced other 640x480 TFT LCDs from digital picture frames. I'm upcycling them 😀

Going through it all on the oscilloscope looking at signals I noticed that the picture frame boards did drive the screen at a higher frequency and was trying to figure out if there's a way to make the SBC's BIOS match this, but I couldn't see a way to do that. Then I had a read of yyzkevin's experiences with getting a VGA LCD working with custom wiring: https://www.yyzkevin.com/clock-signal/
I am so glad this information is shared, the frequences matched up to what my SBC was putting out at ~25mhz so maybe there's no way to change the frequency. Also the amplitude of my clock signal was all wrong, 8 volts peak to peak?

filtering-for-clock.png
I found that my SBC doesn't implement any filtering on the motherboard for the LCD signals so my PCB should have been doing that. To fix that I cut the trace for the clock signal and started bodging on new parts, to match up what the Chips & Tech CT65550 datasheet specifies for filtering. 220pf capacitor and initially I tried resistors in line, that was bad.
44-pin-lcd-connector.jpg
But then I stole this blue filter thing from a scrap PCB's USB data lines and tested again, now the display is 100% working! I need to figure out what this part is called so I can get a fixed PCB version eventually 😀
The clock signal looks cleaner on the scope, the display is great now, it even handles the cross-hatch in the Windows shutdown screen, pixel perfect. All it was was just how 'clean' the clock signal is when there are ~20 other signals in total.
little-sharp-lq080v3dg01-lcd-works.jpg
This means I can start making something to hold this screen and an SBC at last.

Thanks Kevin for sharing your experiences with LCD troubleshooting 😀

Nice stuff. I added a couple more photoframes to the pile to play with. Gotta source those ribbon connectors and hookup stuff.

Both CD-ROMs on the Dell 500MBR have decided it is time to not live anymore. Both are making weird noises so both are physical failures.

FML I just wanted to play Rollercoaster Tycoon.

Rummaging around in the basement for something else this morning and instead instantly found the thing I couldn't find last month.

With the ATX breakout board installed, the BKi810 lives. Couple of things still to work on, but I'm just happy this wasn't another failed project.

Removed some caps. A couple leaked hard with damage (see pic).
While many were still in range, the 5 that failed had higher than expected values (20/30% more), not a good sign.

Others were all in range and with good values.

Leaky caps do harm the board on the long run. This board probably rested flat for years.

Behaviour: the board would power on, stay at max with fans, after 30 seconds shut down.
It was shorting due to cap liquid bridging with GND. Once I removed the dead caps and cleaned the area thoroughly, the board would power on, crash randomly but work.
Having half of the caps working may explain this. Will recap once my order arrives.

Nexxen wrote on 2023-06-09, 13:44:

Removed some caps. A couple leaked hard with damage (see pic). While many were still in range, the 5 that failed had higher than […]
Show full quote

Removed some caps. A couple leaked hard with damage (see pic).
While many were still in range, the 5 that failed had higher than expected values (20/30% more), not a good sign.

Others were all in range and with good values.

Leaky caps do harm the board on the long run. This board probably rested flat for years.

Behaviour: the board would power on, stay at max with fans, after 30 seconds shut down.
It was shorting due to cap liquid bridging with GND. Once I removed the dead caps and cleaned the area thoroughly, the board would power on, crash randomly but work.
Having half of the caps working may explain this. Will recap once my order arrives.

it will be a good fix

interesting that it works without the cap at all, albeit not stable. Often electronics either work or don't, but its these more mysterious things that can frustrate enthusiasts (those who haven't found a cause yet anyway)

gerry wrote on 2023-06-09, 15:35:

Nexxen wrote on 2023-06-09, 13:44:

Removed some caps. A couple leaked hard with damage (see pic). While many were still in range, the 5 that failed had higher than […]
Show full quote

Removed some caps. A couple leaked hard with damage (see pic).
While many were still in range, the 5 that failed had higher than expected values (20/30% more), not a good sign.

Others were all in range and with good values.

Leaky caps do harm the board on the long run. This board probably rested flat for years.

Behaviour: the board would power on, stay at max with fans, after 30 seconds shut down.
It was shorting due to cap liquid bridging with GND. Once I removed the dead caps and cleaned the area thoroughly, the board would power on, crash randomly but work.
Having half of the caps working may explain this. Will recap once my order arrives.

it will be a good fix

interesting that it works without the cap at all, albeit not stable. Often electronics either work or don't, but its these more mysterious things that can frustrate enthusiasts (those who haven't found a cause yet anyway)

It's just POST, I don't go through BOOT.
ON --- Beep --- Cpu model --- OFF

I put some 1000µF 6.3V instead of 1500. All I had on hand, and they are low around 7-800 (other scraps).
I removed everything back again and it's waiting a full recap.
It still could die. 😀

Well I figured the Dell GX1 500MBRs problem(s).

One optical drive was fine
One was genuinely dead
and as a bonus the hard drive failed while I was working on it.

Replaced both optical drives with the newest, fastest beige IDE drives I could find (an LG from 2007 and a 40x Writer from 2002), replaced the single 80GB WD drive with a 40GB WD + 120GB Seagate ATA V series which is a setup more consistent with my policy of keeping OS and data on separate drives for performance/weardown benefits. Now I get to reinstall the OS, drivers, and all my games. Glad I hadn't really played any game on that PC for more than 5 minutes yet so no save data worth noting was lost.

Barring the power supply or motherboard going out I think I've nixxed all obvious points of unreliability.

Not sure if this is an approved retro activity, but I swapped out the stock cooler on my GF MX440 with a generic aluminum HS and a 10mm Noctua:

I like to keep fan noise down to a dull roar, and I rather hate cheap buzzy rattley GPU coolers in general. This AOpen one really isn't near the worst of the bunch. I figure in the era where they were actually trying to keep it down to one slot height there was only so much you could do.

Btw, recently picked up a Voodoo 3:

Is that passive cooling really enough? It gets pretty toasty pretty quickly. Never had one back in the day, so not sure what's normal. Thinking of throwing a fan on it anyway to hopefully extend the life of the card - would like this one to go the distance if possible.

ubiq wrote on 2023-06-09, 22:26:

Btw, recently picked up a Voodoo 3:
IMG_5016.jpeg

Is that passive cooling really enough? It gets pretty toasty pretty quickly. Never had one back in the day, so not sure what's normal. Thinking of throwing a fan on it anyway to hopefully extend the life of the card - would like this one to go the distance if possible.

Has two spare holes to stick a fan to. I'd go for it as it'll make your V3 last longer.

ubiq wrote on 2023-06-09, 22:26:

Not sure if this is an approved retro activity, but I swapped out the stock cooler on my GF MX440 with a generic aluminum HS and […]
Show full quote

Not sure if this is an approved retro activity, but I swapped out the stock cooler on my GF MX440 with a generic aluminum HS and a 10mm Noctua:
IMG_5015.jpeg

I like to keep fan noise down to a dull roar, and I rather hate cheap buzzy rattley GPU coolers in general. This AOpen one really isn't near the worst of the bunch. I figure in the era where they were actually trying to keep it down to one slot height there was only so much you could do.

Btw, recently picked up a Voodoo 3:
IMG_5016.jpeg

Is that passive cooling really enough? It gets pretty toasty pretty quickly. Never had one back in the day, so not sure what's normal. Thinking of throwing a fan on it anyway to hopefully extend the life of the card - would like this one to go the distance if possible.

$13 fan on a $20 GPU

Leaves $200 Voodoo card passively cooled.

-

Big Pink wrote on 2023-06-09, 13:26:

Rummaging around in the basement for something else this morning and instead instantly found the thing I couldn't find last month.

With the ATX breakout board installed, the BKi810 lives. Couple of things still to work on, but I'm just happy this wasn't another failed project.

Is that just a generic ATX breakout board? That looks great. I've gotta try something similar with a DigiPOS computer that has a crazy external PSU.

BitWrangler wrote on 2023-06-09, 02:50:

Thermalwrong wrote on 2023-06-09, 01:21:

Some years ago, my boss at work threw away a little 8" LCD tv from Maplins, which I kept. It could take VGA but looked terrible […]
Show full quote

Some years ago, my boss at work threw away a little 8" LCD tv from Maplins, which I kept. It could take VGA but looked terrible doing it with awkward scaling, but it had a 640 x 480 LCD in it, so I threw away the TV and kept the LCD.

Some months ago I made this PCB for the 44-pin LCD connector that you can find on many industrial PCs and single board computers. Initially I thought it was advantech specific but it seems to be standard across many of the Taiwanese integrators that were making x86 SBCs.
advantech-pca-6145-lcd.jpg
The LCD that I took out of that 8" LCD TV uses a 32-pin flat flex cable with I think 0.5mm pitch pin spacing that's way too small for me to solder, thus this PCB was necessary and it's worked for several other LCD panels but not this little Sharp 8" LCD and I had no idea why. It's been on my 'please fix this at some point' pile for a long time.
It would work with this board but it would show noise on any details on the screen like in the BIOS screen the red & white text would have some break-up here and there. In Windows any details like the start menu were illegible and when doing the Shut down Windows screen which does the cross-hatch thing, the display would just break entirely on displaying that.
Initially I thought it was down to the BIOS on this Advantech PCA6145 and other SBCs that had wrong details to drive this LCD panel since the LCD worked with its original board and the digital picture frame driver boards, where I'd sourced other 640x480 TFT LCDs from digital picture frames. I'm upcycling them 😀

Going through it all on the oscilloscope looking at signals I noticed that the picture frame boards did drive the screen at a higher frequency and was trying to figure out if there's a way to make the SBC's BIOS match this, but I couldn't see a way to do that. Then I had a read of yyzkevin's experiences with getting a VGA LCD working with custom wiring: https://www.yyzkevin.com/clock-signal/
I am so glad this information is shared, the frequences matched up to what my SBC was putting out at ~25mhz so maybe there's no way to change the frequency. Also the amplitude of my clock signal was all wrong, 8 volts peak to peak?

filtering-for-clock.png
I found that my SBC doesn't implement any filtering on the motherboard for the LCD signals so my PCB should have been doing that. To fix that I cut the trace for the clock signal and started bodging on new parts, to match up what the Chips & Tech CT65550 datasheet specifies for filtering. 220pf capacitor and initially I tried resistors in line, that was bad.
44-pin-lcd-connector.jpg
But then I stole this blue filter thing from a scrap PCB's USB data lines and tested again, now the display is 100% working! I need to figure out what this part is called so I can get a fixed PCB version eventually 😀
The clock signal looks cleaner on the scope, the display is great now, it even handles the cross-hatch in the Windows shutdown screen, pixel perfect. All it was was just how 'clean' the clock signal is when there are ~20 other signals in total.
little-sharp-lq080v3dg01-lcd-works.jpg
This means I can start making something to hold this screen and an SBC at last.

Thanks Kevin for sharing your experiences with LCD troubleshooting 😀

Nice stuff. I added a couple more photoframes to the pile to play with. Gotta source those ribbon connectors and hookup stuff.

Cool, which LCD panels have you ended up with? I've got a Toshiba LTM10C209 and that's an industrial panel that's very tolerant of the messy signal I was feeding it. But I don't like its colour reproduction.
Another interesting one I got that takes a flat-flex cable is the Sharp LQ104DG83 - these Sharp panels look great with nice viewing angles, like this little 8" LCD and like on my Toshiba Satellite 400CS that I upgraded to TFT. This Sharp panel came out of a Texet 10.4" digital picture frame and these are the best made ones I've seen so far. Most of the no-name ones were made as cheap as possible but this one has an ESS ES830FAA chip making the video and a separate TSUM16AK driver board that works like a VGA LCD display with screen controls - hope I can figure out how to get VGA into one of these.

Finally got this LQ080V3DG01 behaving with the smaller SBC that I wanted to use it with, this one didn't go so easily. It was still giving noise on complex enough screen:

• In line emi filter on clock line = good improvement, went from unusable to noise on some screens
• Shorter cable = good improvement. This cable is too short but it gives 100% noise-free display
• Bypass capacitor for LCD power = no change
• Changing connector to top opening one = possibly some improvement though that may have been correcting a soldering error for the emi filter.
• Adding copper guitar tape to the outside of the 20cm flex cable, with tape around that for insulation = good improvement, clear & stable on windows shutdown screen at last

Very happy with this now, since the LCD is being driven directly by the graphics chip I think there should be less latency than if it was going through a VGA LCD display. A little LCD with a tiny PC104 SBC is my kind of 486.
Once I tidy up the design a bit I can share the PCB design for this adapter board, you'll notice it has a lot of bodges, but since I only had to worry about 5 of them it's easier to re-work what I've got.

TheAbandonwareGuy wrote on 2023-06-09, 23:22:

$13 fan on a $20 GPU

Leaves $200 Voodoo card passively cooled.

Only the best for my babies 😉 (Had them left over from a failed attempt at heat management in a too-small mITX HTPC build - so, basically they were free for me at this point? Sure..)

And yeah, I'm going to put a fan on the Voodoo, just don't have one for it at the moment. Feedback I'm getting here is that it could benefit from active cooling.

Edit - it's gonna have to be a pretty thin fan! 😛

Hmm.. actually, I think I know where I can find a good temporary fan...