1.6 KiB
1.6 KiB
Computer
Summary
Aims and challenges
Make a turing complete computer from scratch.
The computer will be composed of :
- A CPU
- Some RAM
- Some ROM
At first every part will be the "industrial" version :
- The CPU from logic gates.
- The RAM a SRAM chip (UM61256BK-20 from 1993)
- The ROM another chip (D27C010 from 1986 !)
Then the aim is to replace them with made from scratch versions. For the moment only the RAM is meant to be replaced with homemade magnetic core RAM.
Architecture choices
The computer will be in 8 bits since the RAM and ROM are meant to be in 8 bits. The CPU will have ports for inputs / outputs.
Design
The design is inspired of great people hard work :
The instruction set.
Every instruction is 8 bits long. And there is 3 bytes of data after the instruction. Because the ROM is 8 bits, every instruction will take 4 bytes. This property might help for instruction pipelining in the future.
These are only real instructions. Pseudoinstruction will be defined later.
| Mnemonic | Description | Pseudocode |
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