I kind of want to try to make a "74 series logic" RISC V CPU at some point so I can inherit the compiler. It's rough building the larger systems though. All the early logic is still around for the most part, but most of the "medium integration" parts have disappeared. Things like register files and bitslice ALUs. (74x181, etc.)
An 8-bit minicomputer with a fully custom architecture
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Re: An 8-bit minicomputer with a fully custom architecture
#22I kind of want to try to make a "74 series logic" RISC V CPU at some point so I can inherit the compiler. It's rough building the larger systems though. All the early logic is still around for the most part, but most of the "medium integration" parts have disappeared. Things like register files and bitslice ALUs. (74x181, etc.)
You might enjoy this. https://hackaday.com/2021/12/03/homebrew-16-bit-computer-rei...
Re: An 8-bit minicomputer with a fully custom architecture
#23Slightly off topic, but I'm looking forward to FPGA tooling improving to the point where I can build a fantasy personal computer based on dragging and dropping architectural components into a design that compiles to hardware. I'm definitely too lazy to design from scratch or build by hand, and there's already so much out there designed for FPGAs, so just hoping one day it may be plug and play like the Mister is for e…
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Re: An 8-bit minicomputer with a fully custom architecture
#24Somebody is way too into solderless breadboards. I can see building a CPU from smaller components, but not dealing with loose connections in that mess.
While the color coating of the wires can be useful, I preferred enameled copper wire/magnet winding wire of 0.3mm gauge, when I did such stuff. Maybe 0.2mm, NOT 0.1mm!(too soft) At 0.3mm they are tightly bendable, stay in place after bending them, and can touch each other. This enables building of esthetically pleasing structures, instead of the pictured mess. Imagine something like the pipes screensaver from the WinNT 4 days, but shining in copper. Also usable to wire together LED-cubes or similar structures.
Re: An 8-bit minicomputer with a fully custom architecture
#25Microcomputer??
Re: An 8-bit minicomputer with a fully custom architecture
#26Microcomputer??
Maybe not, if the CPU is built out of discrete components:
https://en.wikipedia.org/wiki/Microcomputer
> A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit (CPU).[2]
Re: An 8-bit minicomputer with a fully custom architecture
#27I kind of want to try to make a "74 series logic" RISC V CPU at some point so I can inherit the compiler. It's rough building the larger systems though. All the early logic is still around for the most part, but most of the "medium integration" parts have disappeared. Things like register files and bitslice ALUs. (74x181, etc.)
I build “74 series logic” computers as a hobby. It’s a lot of fun! It’s not difficult to buy old 74x181 and 74x182 ICs on eBay. You can even get sixteen-bit ALUs like the IDT 7831 for decent prices. Build a register file from a bank of registers. For example, use a 74x138 and a few 74x377. Alternatively, either use a true dual port SRAM to build a three port register file, or build your own from a time-multiplexed SR…
> IDT 7831
My favourite search engines failed to find that one (or I failed to look deep enough). Do you have a link?
Re: An 8-bit minicomputer with a fully custom architecture
#28Neat! But shouldn't this rather be called a nanocomputer? Minicomputers could still fill a room at their time [1]. Our desktop machines are “microcomputers”.
[1]: https://www.computerhistory.org/revolution/minicomputers/11/...
Re: An 8-bit minicomputer with a fully custom architecture
#29Earlier quoted context omitted.
I build “74 series logic” computers as a hobby. It’s a lot of fun! It’s not difficult to buy old 74x181 and 74x182 ICs on eBay. You can even get sixteen-bit ALUs like the IDT 7831 for decent prices. Build a register file from a bank of registers. For example, use a 74x138 and a few 74x377. Alternatively, either use a true dual port SRAM to build a three port register file, or build your own from a time-multiplexed SR…
> IDT 7831 My favourite search engines failed to find that one (or I failed to look deep enough). Do you have a link?
Re: An 8-bit minicomputer with a fully custom architecture
#30Neat! But shouldn't this rather be called a nanocomputer? Minicomputers could still fill a room at their time [1]. Our desktop machines are “microcomputers”. [1]: https://www.computerhistory.org/revolution/minicomputers/11/...
Aside from the RISC instruction set part, all the specs scream standard 8-bit "microcomputer" of the late 70s and early 80s.