PC@LIVE wrote on 2025-01-24, 23:36:

Having the pin connection scheme, you can have the board made, and then you have to solder all the necessary components, maybe 🤔 who has a too damaged board, could make it work again with a new PCB.
For example, I kept an old 386DX from the late 80s, maybe 🤔 it could be repaired with a lot of (a lot of) work, but having a new PCB made, ultimately could be the easiest solution, because you don't have to go in search of traces interrupted by corrosion.

This board with the chipset can only handle 286 CPUs. But I have also created a 386SX board. This uses a 386SX CPU. A different chipset is required for DX. It also has more address lines.

Nelson68k wrote on 2025-01-25, 10:47:

Test the maximum speed. At the moment it is running stable at 24.58 MHz.

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I saw that you have a working card, congratulations 🎊🎈🎉🍾
In the next few days as soon as I can, I will try a fairly similar card, with headland chipset and AMD 12 MHz cpu, and 1 MB of RAM.

both schematics from the 286 and 386 sx would be a awesome starting point for a ht18 Project ( i know chipset is different to HT12). A pdf would be cool for me and i won´t blame anyone for mistakes