It is finally done. My long time dream, ultra small ridiculously overpowered retro PC with real ISA slots so it can run all my childhood DOS classics but also Win9x era classics. For long I thought it is just not possible as there are no Mini-ITX motherboards with ISA, but after I saw "ISA855" - An interesting and peculiar motherboard from ali I thought that I could DIY enclosure around that particular Micro-ATX motherboard which is so small that setup will be smaller than most Mini-ITX setups.

So I started a project which I thought would not take that much time and would be trivial to design and 3D print and not that many prototypes needs to be printed out. Half of year, dozens and dozens of prototypes and many kilograms of 3D filament later it is done! Needed to learn so many new things about 3D designing (not my profession) and final product has many many mistakes due to my inexperience in 3D scene, but I think I can still be proud of it.

Here it is, I nicknamed it ISA Beast as it is quite a best of an ISA machine (all panels etc. are draft quality but I think I won't bother re-printing everything with better quality):

Standard 0.33l can for scale. So frame is cut from makerbeam 1010 aluminium extrusion profiles. 3D printed panels in three colors for some fun. Side panels I did cut from polycarbonate as 3D printing them were insane waste of filament and I printed few prototypes already. Total volume is about 8.7 litres and it can take 2x70mm intake fans to front panel and 2x70mm exhaust fans to top panel. Power toggle, reset, leds, front panel audio, standard stuff. I made a design mistake at some point and no longer could use IO shield from mobo so I also had to customize back panel based on connectors:

You can see from the picture that it can take few low profile cards and one full profile using riser. If you are very sharp eyed you can see that there is extra USB connector, this is integrated Hidman micro (HIDman - USB to PS/2 converter (Open Source)) as mobo conveniently has PS/2 header inside (it really is great motherboard). DC 12V power input (again, great motherboard, it has integrated DC-DC converters for remaining voltages), power switch...

Let's look inside, where fun starts:

So what do we have here? 2.5" SSD on the bottom. This mobo has sata bridge built in(!). Then the beef, ES1868 ISA sound card with Dreamblaster X2SE in low profile! Well it was not low profile but low enough that I was able to 3D print low profile bracket and move joystick port away. This combo works in DOS with just about anything. Then we have 1 Gbps NIC, mobo has 100 Mbps NIC integrated but with a bit more bandwidth I can mount CD-images over the network no problems. Then we have Nvidia Quadro NVS280 GPU, sadly this otherwise great mobo has no AGP and is picky about GPUs, FX5500 PCI does not work, Voodoo 3 PCI did work but wanted a bit more oomph so NVS280 it was. Behind GPU I have another HDD peeking, it is 3D-printed DOM from IDA-mSATA adpter. So I have 120GB + 120GB SSD space in this beast.

CPU is another jewel, mobo is actually based on ICH4-M mobile chipset and can take Pentium M CPUs. I have 1.7 GHz Pentium M installed, it supports speedstep and scales down beautifully to any speed required and has been able to run all games I have tried. Memory is integrated 512MB but luckily that is plenty.

What else... all fans are running 5V via custom DIY fan hub mounted to frame... The thing is very quiet, sadly 70mm fans have some bearing noise and I have not been able to find truly quiet ones. Even Sunon maglevs have bearing noise which is weird because 60mm and 50mm maglevs do not have? But noise is so small that you really need to listen to hear it. Due to highly efficient mobile CPU temps are great as well.

I run DOS games on this thing from 90s onwards, pretty much the games I played as a kid. And Win98SE and games of the era. Even though NVS280 is PCI, it is surprisingly good and overclocks handsomely and i can run like Max Payne and UT2003 with it with comfortable FPS so I think I can conclude that this truly is fine retro setup for anything up to early 2000s... Later games would then require another XP based setup or so...

Final picture, so I modeled everything using Fusion360 from which I know basics, learned so many things and how stupid some of my ways were... Used models from grabcad etc. for cards, fans, ssd etc. so I was able to wiggle everything around in fusion and make sure that everything fits: