Custom built 6502 based computer + system interface controller
- W65C02S 8-bit Microprocessor
- UM61256FK-15 32KB RAM
- Chip enable is tied to addr line 15 of CPU
- Arduino Mega 2560 AVR
- Breadboard
- Shitloads of wires and LEDS
- Resistance (in the form of resistors)
- 128x64 i2c compadible OLED.
- 420-6502 AVR controller (Controller system)
- Power on self test (write/read all RAM addresses)
- Inject Kernel or NOP test program into RAM
- Sets the CPU reset vectors (0x0200)
- Starts the CPU
- Provides a clock for the CPU
- Provides some crude bus management via the 6502 BE pin
- Intercept/monitor CPU address and data lines
- Provides special high memory "registers" and "features"
- Provides a serial debugging interface to PC over AVR USB
- Provides a basic graphics interface
- 420-6502 OS
- Basic Kernel
- Tests the CPU stack is working
- Tests basic logic and RAM reading/writting is working
- Prints Hello World via the AVR "Graphics Driver"
| Start | End | Purpose |
|---|---|---|
| 0x0000 | 0x00FF | Zero Page |
| 0x0100 | 0x01FF | Stack |
| 0x0200 | 0x7FFF | Kernel/Application code |
| Start | End | Purpose |
|---|---|---|
| 0xF420 | - | GFX Register, ASCII char or 0xFF to clear screen |
| 0xFFFA | 0xFFFB | NM Interrupt service routine (not implemented) |
| 0xFFFC | 0xFFFD | Reset Vectors (set to 0x0200) |
| 0xFFFE | 0xFFFF | Interrupt service routine (not implemented) |
Problems with CPU clock timing and read/write IO to high mem?- ~~Some sort of graphical output
AVR Special registers + Display driverOLED or 120x20 LCD?- Pixel GFX mode (x,y,n)
Automate hexdump -> c array of kernel- Possibly send kernel over AVR USB?
- Run faster than 20hz
- Flesh out OS (mateOS?)
- IRQ Support
- String libs
- Cool registers?
- CPU defined clock rate/scaling?
- CPU auto reset
