Here's a more detailed description of the computer I'm building:
It'll have flash memory used as a hard drive; this memory will be programmed from my laptop so long programs can be created and written from text files, making complex programs easier to write. The computer will also, of course, be able to rewrite its flash memory to save data.
The CPU will be able to perform 8 operations: Addition, subtraction, left/right bitshift, bitwise NAND, NOR, AND, XOR, and checking to see if all bits in a byte are ones. It is built from 7400 series ICs, except for the control unit which I'm probably going to make from either EEPROM or a CPLD.
It has 32KB of RAM.
It will also have ports to allow external flash memory to be connected to the computer. The purpose of this is to allow programs to be saved externally and plugged into the computer when you want to run them, and to allow you to save data to external memory.
On the I/O side of things, it will have an array of 7-segment displays for outputting computation results. Furthermore, I'm building a control panel with 8 reprogrammable buttons, switches, and LEDs so that your programs can get user input. Lastly, the main bus (along with some control lines from the CPU) will be routed to a port on the side of the computer so keypads, fancier displays, or whatnot can be connected to the computer and controlled at a later date, should the need arise.
On the manufacturing side of things...
I'm going to order or mill my own PCBs for this computer. It will require some 20-30 boards, so this project is certainly going to take a while. As I get the boards designed, made, and assembled, I'll upload the gerbers and KiCad project files.
Once all the electronics are ready to go, I plan on building one gigantic plywood box to house this beast. Lastly, I'll give it a nice pretty control panel with loads of switches and blinkenlights (maybe even a buzzer to yell at you) to really tie the whole thing off.