In the Spirit of the Homebrew Computer Club – Building a Homebrew 8088 Computer Part 2

The 0: at the top shows the segment, which is 0x0000. On lines 2-4, the four left-most digits are the offsets. Everything to their right is memory.

Click here for the GitHub repository.

The pictures here were taken before I completed the current version. As you can see, it had a premature version number in the picture, and it doesn’t show the full screen of memory contents.

I finally got around to posting the code for MemDump, a program I wrote for my 8088 computer (back in July, last year *eye roll*) to display the contents of memory. I have used it extensively so far to see if my interrupts and interrupt vector table (IVT) are installed correctly in low memory.

I restarted my homebrew 8088 computer from scratch, and replaced the original 2 KB of SRAM with 384 KB (I left room in the memory map to add 256 more KB for a final total of 640 KB). I also wrote a firmware program to initialize the interrupt vector table, added an interrupt controller, completely redesigned the control signal demultiplexing circuitry (which both improved the efficiency and decreased the complexity), and wrote a simple demo program to display a memory dump in hexadecimal.

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