BuLWiP - a TI/99 4/A emulator in C w/SDL2

• Features 9918A video and 9919 sound chip emulation.
• Lower memory usage, less lookup tables, keep important data in cache
• Instruction opcode decoding using CLZ instead of a lookup table
• Memory is designated as 16-bit words as seen from the CPU; no need for builtin_bswap16
• Memory accesses use a function pointer per 256 bytes
• Instruction loop is in a single function; keeping PC, WP, (maybe ST) in host CPU registers
• Instruction decoding functions inlined; better branch prediction

Requires ROM and GROM files: 994arom.bin, 994agrom.bin. Put them in the same directory as the emulator executable. (If you want to have a ROM source listing, it should be named '994arom.lst'.)

Keyboard usage:

• ESC: Load Cartridges/Settings/Quit menu
• F11: Toggle full-screen
• F12 or Ctrl-Home: Toggle debugger interface
• Ctrl-F12: Reset and reload current cartridge/listings
• Shift-Insert: Paste from clipboard
• Arrow keys and Tab are mapped to Joystick 1.

Loading Cartridges:

• Files ending in G.BIN are assumed to be GROM, otherwise ROM.
• ROM files must be non-inverted (first bank is 0) format.
• Listing file is loaded automatically and must be named the same as the ROM with a .LST extension.
• Cartridge files may be loaded by drag-n-drop onto window.

While debugger is open:

• F1: Run/Stop
• F2: Single instruction step
• Ctrl-F2: Single frame step
• Up/Down/PgUp/PgDn: move highlighted line in listing
• Home/End: Go to start/end of listing
• Ctrl-F: Find text string
• Ctrl-G: Repeat last find
• Shift-Ctrl-G: Repeat last find, reverse direction
• B: Toggle breakpoint at current line (red=stop, green=go)
• Del: Remove breakpoint at current line
• F5: List breakpoints
  • Enter: Go to selected breakpoint
  • Space: Toggle selected breakpoint
  • Del: Remove selected breakpoint
• R: Register select, then Enter to jump to address
• Z: Reverse instruction step
• Shift-Z: Reverse instruction step until PC goes lower (good for rewinding out of a loop)
• 1/2/3/S: Show character pattern tables, or sprite pattern table
• TODO Ctrl->B: Go to referenced label
• SAMS banking 1MB

TODO

• F18A support (some bits work)
• FinalGROM99 cartridge emulation (paged 4Krom+4Kram, gram, load, dump)
• Memory view:
  • A: set address
  • M: CPU memory
  • V: VDP memory
  • G: GROM
  • S: SAMS

Android? (https://github.com/cnlohr/rawdrawandroid)