## Boot ROM
Execution starts here, at address `$0000`.
The main program is located here, or the OS bootloader if an OS is present.
## GPIO
Contains hardware multiplication (`$0400 * $0401 -> $0400`) and division (`$0402 / $0403 -> $0402 r $0403`), popcount (`$0404 -> $0404`), and a timer (`$0405`).
Value written to timer register = number of game ticks (32 ms) between interrupt triggers.
Write 0 to disable.
## Keyboard
Read address `$0500` to get the next key event
7-bit Windows VKey code, MSB 1 = press, 0 = release
Returns 0 if buffer is empty.
Write 1 to `$0500` to enable keyboard interrupts, 0 to disable.
## Serial Peripheral Interface
Not yet implemented.
## Robot Controller
Write to `$0701` to control the robot. Each bit is an action - MSB to LSB: Plant brick, destroy brick, move forward, backward, left, right, up, down.
Write a 6-bit color ID to `$0700` to set the color of the bricks the robot plants.
Read `$0700` to get the color of the brick the robot is on. MSB = brick exists. Returns 0 if no brick.
## Text Display
Write ASCII values to `$0800` to `$0BFF` to display characters at certain positions on screen.
`$0800` is top left, `$0BFF` is bottom right, rows are 64 bytes.
## Text Display Color
Write 6-bit color IDs to `$0C00` to `$0FFF` to set the color of characters on screen.
MSB = whether to invert character mask (i.e. for highlighting).
## System RAM
The OS may use this memory for the stack, system variables, etc.
If no OS is present, this memory can be used for any purpose, etc.
Located at `$1000` to `$1FFF`.
## User ROM
User program and data can go here.
If no OS is present, the boot ROM will need to jump into this code.
Located at `$2000` to `$2FFF`.
## User RAM
Your code can use this memory for variables, arrays, a heap, etc.
Located at `$3000` to `$3FFF`.