THAWcpu 1.1.1
THAWcpu emulates a 4-bit mini computer I once designed from scratch using CMOS 40xx chips. Alas, I never got around to actually solder it together, but all the plans are there…
Note that this computer does not adhere to the von-Neumann-principle. The data and the operating instructions are not stored in the same memory. The data memory has room for four values (4 bit each) and the operating instructions memory allows a maximum of 16 instructions (6 bit each).
The “classic” processor has the following instruction set:
| Binary | Mnemoic | Instruction |
|---|---|---|
| 0000 | NOP | No operation |
| 0001 | undefined | |
| 0010 | SMO | Set accu minus one |
| 0011 | CLA | Clear accu |
| 0100 | OTP | Acknowledge output |
| 0101 | STA a | Store accu into register |
| 0110 | CMA | Complement accu |
| 0111 | INC | Increment accu |
| 1000 | INP | Get input |
| 1001 | undefined | |
| 1010 | undefined | |
| 1011 | LDA a | Load register into accu |
| 1100 | ADD a | Add register to accu |
| 1101 | undefined | |
| 1110 | SUB a | Subtract register from accu |
| 1111 | HLT | Halt |
More information is available in the enclosed usage instructions (RTF).
System Requirements
Minimum supported: Mac OS 8.6 (with CarbonLib 1.3) or Mac OS X
Recommended: Mac OS 9 (with CarbonLib 1.6) or Mac OS X
Download
Download THAWcpu 1.1.1 (791 kB)
This program is free software, subject to the terms and conditions of the GNU General Public License.
Screenshots
![[Screenshot 1]](screen1.png)
![[Screenshot 2]](screen2.png)
Version History
- Version 1.1.1
- New about box.
- Minor changes.
- There is no changelog available for earlier versions.
Future Plans
- Add another processor type with 8 bit addressing and one 256 byte memory (von-Neumann-principle).
License
This program is free software. You can redistribute it and / or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the GNU General Public License for more details.
