# MatCat 8SA1 CPU Simulator

This is a simple JS based simulator to simulate the function of the 8SA1 CPU.

## Work In Progress

### ISA Layout

#### LDx 0x0000:0x00FF / STx 0x0100:0x01FF

| bits | mode |
| --- | --- |
| 0b000XXXXX | Immediate (8/16) |
| 0b001XXXXX | Absolute + (Immediate (16) Offset) |
| 0b010XXXXX | Absolute (16) |
| 0b011XXXXX | Absolute (24) |
| 0b100XXXXX | Indirect (16) |
| 0b101XXXXX | Indirect (24) |
| 0b110XXXXX | Indirect + (Immediate (16) Offset) |
| 0b111XXXXX | Absolute + (Absolute (16) Offset) |

| Registers | bits | 
| --- | --- |
| AL  | 0b00010	0x02 |
| AH  | 0b00011	0x03 |
| BL  | 0b00100 0x04 |
| BH  | 0b00101	0x05 |
| CL  | 0b00110	0x06 |
| CH  | 0b00111	0x07 |
| DL  | 0b01000	0x08 |
| DH  | 0b01001	0x09 |
| AB  | 0b01010	0x0A |
| AC  | 0b01011	0x0B |
| AD  | 0b01100	0x0C |
| BA  | 0b01101	0x0D |
| BC  | 0b01110	0x0E |
| BD  | 0b01111 0x0F |
| CA  | 0b10000	0x10 |
| CB  | 0b10001	0x11 |
| CD  | 0b10010	0x12 |
| DA  | 0b10011	0x13 |
| DB  | 0b10100	0x14 |
| DC  | 0b10101 0x15 |

#### Tx 0x0200:0x027F

#### PHx/PLx 0x0280:0x02BF

#### Jumps 0x2C0 - 0x2FF

#### ALU 0x0300 - 0x3DF

#### NOP 0x3FF