2023-03-27 22:54:48 +00:00
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# Chirp
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2023-03-10 21:33:02 +00:00
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How does an emulator work?
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I don't know!
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So I wrote this, to see if i can find out.
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2023-03-27 22:54:48 +00:00
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## Features:
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- 32 * 64 1bpp pixel display, scaled 16x
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- Full coverage of the original Chip-8 insn set
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- 64-bit floating point internal sound/delay timers
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- Pause/Resume
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- Set and unset breakpoints
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- A fairly nice command-line interface
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## Keybinds:
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- F1: Dump CPU registers
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- F2: Dump screen to terminal
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- F3: Dump screen to file
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- F4: Enable/Disable live disassembly
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- F5: Pause/Resume
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- F6: Single-step instruction
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- F7: Set breakpoint at current instruction
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- F8: Unset breakpoint at current instruction
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- F9: Soft-reset the CPU
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## Keypad mapping:
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### QWERTY:
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| | | | |
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|---|---|---|---|
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| 1 | 2 | 3 | 4 |
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| Q | W | E | R |
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| A | S | D | F |
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| Z | X | C | V |
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### Chip-8:
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| | | | |
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|---|---|---|---|
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| 1 | 2 | 3 | C |
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| 4 | 5 | 6 | D |
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| 7 | 8 | 9 | E |
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| A | 0 | B | F |
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## Command Line Interface:
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```
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Usage: chirp [OPTIONS]
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Positional arguments:
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file Load a ROM to run on Chirp.
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Optional arguments:
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-h, --help Print this help message.
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-d, --debug Enable debug mode at startup.
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-p, --pause Enable pause mode at startup.
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-s, --speed SPEED Set the instructions-per-frame rate.
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-S, --step STEP Run the emulator as fast as possible for `step` instructions.
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-z, --vfreset Disable setting vF to 0 after a bitwise operation.
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-x, --drawsync Disable waiting for vblank after issuing a draw call.
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-c, --memory Use CHIP-48 style DMA instructions, which don't touch I.
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-v, --shift Use CHIP-48 style bit-shifts, which don't touch vY.
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-b, --jumping Use SUPER-CHIP style indexed jump, which is indexed relative to v[adr].
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-B, --break BP Set breakpoints for the emulator to stop at.
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-D, --data WORD Load additional word at address 0x1fe
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-f, --frame-rate FR Set the target framerate. (default: 60)
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```
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## TODO:
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- [ ] Implement sound
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- [ ] Finish unit tests for "quirks"
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- [ ] Make pausing/unpausing the emulator less messy
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- [ ] Make resetting the emulator possible
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- [ ] Allow code to be passed in hex on the command line? Hmm
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- [ ] Assembler for my assembly syntax
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- [ ] Make a UI for realtime configuration
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- [ ] Cycle accuracy with original Chip-8 interpreter
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