Another cool piece of hardware I acquired recently.
486 DX4 100MHz ISA SBC Single Board Computer Model# HS5X86HVGA v1.6
More info by this URL https://theretroweb.com/motherboards/s/icp-ssc-5x86hvga
One gentleman from Minnesota kindly sold it to me for a very affordable price.
It turned out to be not a very rare SBC, it can still be found on eBay even now, but that doesn't make it any less interesting to me..
Couple of reasons why I'm creating this thread: 1) we still don't have a separate thread for that SBC 2) I've fixed the DMA1 problem and would like to share the fix.
This computer has one problem as was said. When I tried to use the CT-1320C clone (known as The Snark Barker), it refused to work. After software diagnostics, it turned out that the DMA 1 channel does not work. At first, the version was that this is a good old hardware conflict, but I decided to study the ISA bus on this SBC and it turned out that DRQ1 is not connected to the M1487 controller at all. The diagram and photo of how I fixed that will be in the next post. As a result, after connecting DRQ1 to the controller via patch, everything started working as it should. The interesting thing is that the DRQ1 is connected to the FDC37C669 (SMSC). This is the controller of the FDD, IDE, COM ports, LPT etc. I haven’t researched why exactly DMA is needed there, perhaps for PCI E-IDE.

That SBC has : 1) VGA Cirrus Logic 5430 2) PS/2 keyboard 3) PS/2 mouse 4) two COM ports 5) IDE 6) FDD 7) LPT.
Supports up to 64Mb DRAM.