As much as I would love to sink hours into troubleshooting CRLF issues, I truly have better things to do; Git converts LF into CRLF and the interpreter doesn't like that, so make sure you convert them back to LF!

Put .basm scripts in the resources/ folder. Not included in this repository are the include files, libraries, and .dlls for SDL2 and SDL2_image.

Compile on Windows from a Visual Studio console with the build.bat script.

• [0-9]+ decimal
• x[0-9a-f]+ hex
• b[01]+ binary

In opcode descriptions, [R] means any register (axy), [N] means any integer, [A] means any address. [L] means a label. Addresses are indirect references; e.g. lda #0 will place the value located at memory address 0 in the accumulator. Most [RNA] commands will accept a second [RNA] parameter separated by a comma; this will produce a reference to a memory address where the second parameter acts as an offset.

There are 4 processor flags: Carry, Zero, Parity, and Sign. Various operations set them in different ways.

• ld[R] [RNA]: Load a value in a register
• st[R] [RNA]: Store a register's value
• inc: Increment the accumulator
• dec: Decrement the accumulator
• add [RNA]: Add a value to the accumulator
• sub [RNA]: Subtract a value from the accumulator
• cmp [RNA]: Compare a value to the accumulator
• jmp [L]: Move the code pointer in memory
• jc [L] / jnc [L]: Jump if C is (not) set
• jz [L] / jnz [L]: Jump if Z is (not) set
• jpe [L] / jpo [L]: Jump if P is (not) set
• jm [L] / jp [L]: Jump if S is (not) set
• call [L]: Push the code pointer to the call stack and move to a label
• ret: Pop the topmost entry of the call stack and move the code pointer there For each of these jump instructions, there is a corresponding c (call) instruction that pushes the current code pointer to the call stack and a r (return) instruction that pops it.
• push [R] / pop [R]: Push/pop data onto the stack from a register

You can write to anywhere in this region.

There are 32 8x8 sprites available for use. Sprites can be disabled by setting their color to black (0xFFFFFF).

• 8x8 pixel data (8 bytes)
  • Laid out by row, leftmost pixel on most significant bit
• Position (2 bytes)
• Color (3 bytes)
• 3 blank bytes