Great techie video. I would not want today to be like this, but once upon a time a mere mortal could build and troubleshoot computer equipment. I wish I could go back when I was in high school in the late 70's and share a little about what I've learned since then. I was real close to being smart and could have done some cool stuff.
I remember when the 8008 came out as a successor to the 4004. I wanted to use one but they were too expensive for me at the time. When I did have enough to start building microprocessor boards I started with Motorola 6800 and then moved to the 6809.
Thank you so much for all you have done to generate new interest in the H8 and the early days of personal computing. Maybe the H8 was not as sexy as the IMSAI and Altair 8080 boxes but to the H8's credit, not flipping those cute but annoying switches to do the simplest of task was a huge improvement. Besides, I have built the Altair and IMSAI clones as well as the PDP 8 and 1170 for my blinking light fetish. ;) Please MORE H8 projects !! 73 Glenn WA4AOS
Awesome project! I'd like to see some benchmarks. Perhaps do a basic program on that vs a z80a computer. I'm not sure what but someone here may have ideas.
This is VERY cool. The 8008, along with the 1802, were the only processors I didn't work with back in the day. I even did a fair amount with the 4004/4040. But why the HCT logic? With the speeds in question, I'm puzzled why not just plain old LS, or even straight TTL. Next iteration needs to address memory on the H8 bus - just because! Great job on this!!!
I mostly try to keep in stock just one family of logic, and it's HCT. The HCT almost always substitute fine in place of an LS. I'm sure an LS build or a straight TTL build would be fine. I'm going to have to give it a shot!
Later H8 computers had the option to switch the radix to base 16, in which case the display would switch to match. I think when you upgraded, it even came with either new keys or new stickers for the existing keys to label the hex digits on them. In my case, the front panel is a newer reproduction using cherry MX keyswitches and custom printed keycaps, with backlighting -- something the folks at SEBHC came up with.
Three bus cycles just to read or write one byte, no RAM stack, TTL... Yikes! Some real CPU archeology going on here. Kind of wild that 50 year old silicon still works. I do not trust simple resistors that are so old. Does the 8008 run hot? Aren't you a little afraid to use it?
