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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Building a Homebrew 8088 Computer Part 1

A Little Background Story

Back in 2013 I wanted to learn how to build a homebrew computer, like what hackers and hobbyists did back in the 1970s during the homebrew computer craze. Although I was about 40 years late, I wanted to make a homebrew computer of my own. Sure, there are much better computers nowadays, but unless you can make circuit boards that have REALLY small solder connections, you can’t really make your own from scratch.

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