readme.md: Update readme.md with useful information

readme.md

@@ -1,12 +1,75 @@
-# Chumpulator
+# Chirp
 
 How does an emulator work?
 I don't know!
 
 So I wrote this, to see if i can find out.
 
-### TODO:
-- Timing (insns should run at about 500Hz)
-- Screen (Memory is present, drawing sprites is not)
-- Sound (Beep boop, how to make noise?)
-- Which abstractions are useful?
+## Features:
+- 32 * 64 1bpp pixel display, scaled 16x
+- Full coverage of the original Chip-8 insn set
+- 64-bit floating point internal sound/delay timers
+- Pause/Resume
+- Set and unset breakpoints
+- A fairly nice command-line interface
+
+## Keybinds:
+- F1: Dump CPU registers
+- F2: Dump screen to terminal
+- F3: Dump screen to file
+- F4: Enable/Disable live disassembly
+- F5: Pause/Resume
+- F6: Single-step instruction
+- F7: Set breakpoint at current instruction
+- F8: Unset breakpoint at current instruction
+- F9: Soft-reset the CPU
+
+## Keypad mapping:
+### QWERTY: 
+|   |   |   |   |
+|---|---|---|---|
+| 1 | 2 | 3 | 4 |
+| Q | W | E | R |
+| A | S | D | F |
+| Z | X | C | V |
+### Chip-8:
+|   |   |   |   |
+|---|---|---|---|
+| 1 | 2 | 3 | C |
+| 4 | 5 | 6 | D |
+| 7 | 8 | 9 | E |
+| A | 0 | B | F |
+
+## Command Line Interface:
+```
+Usage: chirp [OPTIONS]
+
+Positional arguments:
+  file                 Load a ROM to run on Chirp.
+
+Optional arguments:
+  -h, --help           Print this help message.
+  -d, --debug          Enable debug mode at startup.
+  -p, --pause          Enable pause mode at startup.
+  -s, --speed SPEED    Set the instructions-per-frame rate.
+  -S, --step STEP      Run the emulator as fast as possible for `step` instructions.
+  -z, --vfreset        Disable setting vF to 0 after a bitwise operation.
+  -x, --drawsync       Disable waiting for vblank after issuing a draw call.
+  -c, --memory         Use CHIP-48 style DMA instructions, which don't touch I.
+  -v, --shift          Use CHIP-48 style bit-shifts, which don't touch vY.
+  -b, --jumping        Use SUPER-CHIP style indexed jump, which is indexed relative to v[adr].
+  -B, --break BP       Set breakpoints for the emulator to stop at.
+  -D, --data WORD      Load additional word at address 0x1fe
+  -f, --frame-rate FR  Set the target framerate. (default: 60)
+  ```
+
+## TODO:
+
+- [ ] Implement sound
+- [ ] Finish unit tests for "quirks"
+- [ ] Make pausing/unpausing the emulator less messy
+- [ ] Make resetting the emulator possible
+- [ ] Allow code to be passed in hex on the command line? Hmm
+- [ ] Assembler for my assembly syntax
+- [ ] Make a UI for realtime configuration
+- [ ] Cycle accuracy with original Chip-8 interpreter