The Whizz-80 is my latest electronic project that I am starting. It is a combination of hardware and software so it aligns both my passions.
My Whizz-80 computer will be a retro based computer using the Z80 CPU. The Z80 was used in early microcomputers (such as the Microbee and the TRS-80). It will however run it’s own operating system and it’s own specific hardware configuration. I don’t intend on making a clone, (there are plenty of emulators for that) but a unique computer just for me. It’s a great way to learn how computers actually work and since studying it I have a greater appreciation and respect of the hardware of modern computers.
So why use a Z80 chip instead of a different one like based on the 6502 (as in Commodore64)? There are many blogs out there comparing the 2, but the reason why I chose the Z80 over the 6502 was simplicity and documentation. The Z80 requires minimum components to get started while the 6502 needs a few extra chips to get started. There also seems to be a better supply of Z80 components (They still make them!) than the 6502, so Z80 components are more easier for me to obtain (I’m sure your mileage might be different). Also, since this is my first major build, I wanted to keep it as simple as possible and have something up and running as early as possible.
My initial thoughts, goals and ideas for the Whizz-80 computer are as follows:
Whizz-80 Hardware Specs:
The CPU will be based on the Z80 CPU running at around 6Mhz max. 32Kb ROM and 32Kb RAM. This is more than enough memory for our needs, however it simplifies the amount of extra logic circuitry required if you use smaller memory chips.
Operating System I will write and will be Forth based. I’ve always been intrigued with the Forth language, but I will probably tackle this once I have the hardware built Stay tuned for upcoming blog posts on more of the Whizz-80 computer.