Very nice work, always nice to make a one of a kind and it looks lovely too.

I actually looked into making a build with an SBC, there's somebody on eBay selling Pentium 133 boards for £125 a pop - they seem to be old but unused stock, the seller is claiming they're ex-military parts which is interesting. I just wasn't sure what the backplane options were; didn't realise it was as simple as a powered riser.

Probably wouldn't go as small as you have for my own build, but again, super work!

Dan386DX wrote on 2024-03-23, 00:35:

Very nice work, always nice to make a one of a kind and it looks lovely too.

I actually looked into making a build with an SBC, there's somebody on eBay selling Pentium 133 boards for £125 a pop - they seem to be old but unused stock, the seller is claiming they're ex-military parts which is interesting. I just wasn't sure what the backplane options were; didn't realise it was as simple as a powered riser.

Probably wouldn't go as small as you have for my own build, but again, super work!

For a card of that form factor, I would be seriously considering fitting it inside a keyboard - it's just a shame those particular boards are minus the video output. If they had a pc104 connector you could probably even sandwich a very small pc104 based sound card on top and still fit it in a (big) keyboard case.

I like the options these all in one designs give to creating alternate/wacky form factors!

Floppy drive retention mechanism done:

Two recessed screws one side, and the other side of the floppy is wedged against a wooden rail, so it can be slid out when the two screws are removed.

Front panel is glued on now and just waiting to dry.

All the switches and leds are wired up to push on Dupont connectors, I will have the power button to solder to the ps_on pin on the Pico psu, and a power indicator led connected to the +3.3 line on the atx plug.

Found my 60mm hole saw and will therefore be making the last mods to the case tomorrow. Then putting it all together.

megatron-uk wrote on 2024-03-23, 08:29:

For a card of that form factor, I would be seriously considering fitting it inside a keyboard - it's just a shame those particular boards are minus the video output. If they had a pc104 connector you could probably even sandwich a very small pc104 based sound card on top and still fit it in a (big) keyboard case.

I like the options these all in one designs give to creating alternate/wacky form factors!

Y'know that gets me thinking, dead Amiga A500s are not uncommon - looks wise it's just a chunky keyboard, could probably engineer an SBC into one of those and take advantage of the power supply and maybe even the floppy with a little tinkering.

Dan386DX wrote on 2024-03-24, 04:41:

megatron-uk wrote on 2024-03-23, 08:29:

For a card of that form factor, I would be seriously considering fitting it inside a keyboard - it's just a shame those particular boards are minus the video output. If they had a pc104 connector you could probably even sandwich a very small pc104 based sound card on top and still fit it in a (big) keyboard case.

I like the options these all in one designs give to creating alternate/wacky form factors!

Y'know that gets me thinking, dead Amiga A500s are not uncommon - looks wise it's just a chunky keyboard, could probably engineer an SBC into one of those and take advantage of the power supply and maybe even the floppy with a little tinkering.

Just the thing....

https://www.ebay.co.uk/itm/134313817942?mkcid … emis&media=COPY

Amiga keyboard to pc adapter... It's usb, but I would bet there will be a PS2 equivalent.

First coat of linseed oil applied:

I'll finish it off with another coat once the hole for the CPU fan is cut out.

That case looks beautiful seriously great job!!

That looks amazing! Excellent job!

I always thought it would be neat to attempt a proper wooden case. This project is very inspiring!

CPU cooler fan now mounted:

Now comes the fun/tedious/skin-shredding part of trying to (neatly) fit all of the cables inside the case as I finally put it all together!

It's going to be very tight....

That's a fine job you did there. CPU exhaust came out really well.

megatron-uk wrote on 2024-03-25, 17:10:

CPU cooler fan now mounted: […]
Show full quote

CPU cooler fan now mounted:

IMG_20240325_170543_(1200_x_900_pixel).jpg

Now comes the fun/tedious/skin-shredding part of trying to (neatly) fit all of the cables inside the case as I finally put it all together!

It's going to be very tight....

That is a nice project, congratualtions. You are lucky because your board is in working condition in spite of the past harsh operating enviromnet.

I am not so lucky with these boards. I got a Advantech PCA-6752 in a good shape. It is very similiar to yours in size. Unfortunately the board is not working. It has Via VT8501 chipset. As I measured the CPU clock is disabled by 8501 on the clock generator IC. 8501 is in BGA package no canche to measure anything. I was not able to find datasheet for this chip. Who knows what external conditions are required for this chip to disable the cpu's clock? Voltage rails are OK, reset is working, clock ic is working. But everything else is stopped. No activites on the BIOS's address-data lines. If you have any suggestions what should be worth to look at please share with me.

Thank you!

Swapped over the DX4-100 with my old Am5x86-133 processor.... and it seems to be locked in x3 multiplier mode, despite setting the jumpers to what the manual says is correct for the AMD X5-133.

CHKCPU also reports 'either Am486-100 or Am586-133 in 3x mode'... and the Speedsys report shows barely any difference to the previous Intel DX4-100 results.

I'm hoping that there is just a wrong jumper set somewhere, otherwise I'd be better off putting the Intel DX4 back in and saving the AMD chip.

I want to get this sorted before buttoning up the case with all the cables in. As I mentioned before; it's tight!

Found a couple of transposed jumper numbers in the manual, once corrected the X5 is now correctly shown and internal CPU cache performance has significantly improved:

It's solid, but is not going to win any awards for fastest 486 system ever. I suspect memory bandwidth is never going to be optimal due to the single simm layout. Still, it plays the dosbench doom timedemo at ~39fps so it's not that far off the pace.

Last thing left to with the config of the SBC itself is to replaced the 32MB simm with a 64MB (overkill much?), as the smaller capacity module is older and quite high. Once I've got that done, I'll start to configure the MT32Pi install and get the sound card slotted into the case.... if I can find the space....

All cards and cabling now installed.

Oh how modern sata cabling has spoiled us!

McCake isn't working, but the host ESS 1868 soundcard is configured and working via unisound okay (both fm and digital sound are fine)... I'm wondering if the soundcard isn't supplying enough power via the waveblaster header (I don't have a free fdd power connector for the board itself). I'll have to wait until I can add a sata power extender and a couple of fdd power splitters (Pico psu just has a SATA and a fdd connector which isn't enough for the SBC, fdd and now the mccake).

How many led's are supposed to be lit on the back of the mccake board? I see the first two (Pi and DAC, is what they appear to be labelled with?), but the rest are unlit. It's difficult to see with all the cards and cabling in place.

It's getting very tight in there.

One mod I am already thinking of making is drilling some vent holes above the Pico psu, it gets warm... Not horrendously so, but enough to make me want to let the heat vent directly out of the case.

megatron-uk wrote on 2024-04-01, 10:00:

McCake isn't working, but the host ESS 1868 soundcard is configured and working via unisound okay (both fm and digital sound are fine)... I'm wondering if the soundcard isn't supplying enough power via the waveblaster header (I don't have a free fdd power connector for the board itself). I'll have to wait until I can add a sata power extender and a couple of fdd power splitters (Pico psu just has a SATA and a fdd connector which isn't enough for the SBC, fdd and now the mccake).

The FDD power connector isn't optional. The McCake will not work without it. Could you disconnect your floppy drive and use it to power the McCake instead to test that something else isn't going on until your power splitter arrives?

SScorpio wrote on 2024-04-01, 11:30:

megatron-uk wrote on 2024-04-01, 10:00:

McCake isn't working, but the host ESS 1868 soundcard is configured and working via unisound okay (both fm and digital sound are fine)... I'm wondering if the soundcard isn't supplying enough power via the waveblaster header (I don't have a free fdd power connector for the board itself). I'll have to wait until I can add a sata power extender and a couple of fdd power splitters (Pico psu just has a SATA and a fdd connector which isn't enough for the SBC, fdd and now the mccake).

The FDD power connector isn't optional. The McCake will not work without it. Could you disconnect your floppy drive and use it to power the McCake instead to test that something else isn't going on until your power splitter arrives?

Well that would definitely explain it.... I'll have to partially disassemble it again to try it, but it that sounds like a worthwhile test.

Congrats on an amazing build, could you please show us picture from the front without the front pane on ? I am curious how you solved the CPU fan.

I'm afraid the front panel is now glued in place - it isn't coming back off again!

I can try to take a picture of how the CPU/case fan is mounted in the case above the heatsink on the SBC card though. I will need to remove the cards again anyway to fit the new fdd power splitter cable and reroute things to be a bit neater.

That's the physical and electrical part of the build all finished!

Connected up and working! The combination PS2 KB/Mouse port also works without issue with an off-the-shelf PS2 Y-cable, which is a big bonus. I hate serial mice.
I swapped out the noctua noise reducer fan extension (150Ohm) with a slightly less restrictive one (60Ohm, I believe), since the cooling fan was spinning a little slower than I would have liked - it's still fairly quiet, but sucks enough air into the case to feel the exhaust exiting through the rear IO panels - it should be more than sufficient to keep the AMD 5x86 cool sitting directly under it.

I've started to set up the CF card and recently found that The Last Byte supports the VLB chipset of the SBC, which results in a ton of free UMB and plenty of free base memory without doing much special at all.

Everything works really well - I'm just making final tweaks to the MT32pi configuration now. Since I don't have any button control I'm using mt32pi-control to swap MT-32/GM/GS configuration and soundfonts via MIDI control codes. Still undecided about which soundfont to use for fluidsynth.....

Currently going through all of the games and now testing to ensure that they all function correctly/work with midi/don't run too fast on this box.

As part of that process I found enough problems with TLB and Jemm386 to warrant moving back to standard himem and emm386. The difference isn't huge: 618k Vs 627k.

The games (around 300 of them, so far checked 90-ish) are from a tree I have curated for Dosbox and I am getting a good hit rate with speed sensitivity, softmpu and general playability so far... Although not without problems; there are some odd titles that have been working on my others,.previous retro systems (and Dosbox), that have got weird behaviour.

I'll post the list when I am done, but the standout ones so far that have trouble are the Legend Entertainment adventures which cause the system to lock up when played with midi via SoftMPU.