diff --git a/script/instructions.go b/script/instructions.go index 894db26..bc494a3 100644 --- a/script/instructions.go +++ b/script/instructions.go @@ -17,8 +17,14 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0x81, 0, 0, 0, "halt"}, &Instruction{ 0x82, 0, 0, 0, "tape_nmi_shenanigans"}, &Instruction{ 0x83, 0, 0, 0, "tape_wait"}, + + // Jump to the inline word, in the VM &Instruction{ 0x84, 0, 2, 0, "jump_abs"}, + + // Call a routine at the inline word, in the VM &Instruction{ 0x85, 0, 2, 0, "call_abs"}, + + // Return from a previous call &Instruction{ 0x86, 0, 0, 0, "return"}, &Instruction{ 0x87, 0, 0, 0, "loop"}, &Instruction{ 0x88, 0, 0, 0, "play_sound"}, @@ -35,7 +41,9 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0x92, 0, 0, 1, "string_less_than_equal"}, &Instruction{ 0x93, 0, 0, 1, "string_greater_than_equal"}, &Instruction{ 0x94, 0, 0, 1, "string_greater_than"}, - &Instruction{ 0x95, 1, 0, 0, ""}, + + // Sets some tape NMI stuff if the byte at $0740 is not zero. + &Instruction{ 0x95, 1, 0, 0, "tape_nmi_shenigans_set"}, &Instruction{ 0x96, 0, 2, 0, "set_word_4E"}, &Instruction{ 0x97, 2, 0, 0, ""}, &Instruction{ 0x98, 1, 0, 0, ""}, @@ -50,11 +58,17 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0xA0, 2, 0, 1, ""}, &Instruction{ 0xA1, 1, 0, 0, ""}, &Instruction{ 0xA2, 1, 0, 0, "buffer_palette"}, - &Instruction{ 0xA3, 1, 0, 0, ""}, + + // Possibly a sprite setup routine. loads up some CHR data and some palette + // data. + &Instruction{ 0xA3, 1, 0, 0, "sprite_setup"}, &Instruction{ 0xA4, 3, 0, 0, ""}, &Instruction{ 0xA5, 1, 0, 0, "set_470A"}, &Instruction{ 0xA6, 1, 0, 0, "set_470B"}, - &Instruction{ 0xA7, 0, 0, 0, "call_asm"}, // built-in ACE, lmao + + // jump to the inline address, in assembly, not in the VM + // (built-in ACE, lmao) + &Instruction{ 0xA7, 0, 0, 0, "call_asm"}, &Instruction{ 0xA8, 5, 0, 0, ""}, &Instruction{ 0xA9, 1, 0, 0, ""}, &Instruction{ 0xAA, 1, 0, 0, ""}, @@ -71,22 +85,32 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0xB4, 0, 0, 0, ""}, &Instruction{ 0xB5, 0, 0, 0, ""}, &Instruction{ 0xB6, 0, 0, 0, ""}, - &Instruction{ 0xB7, 0, 2, 0, "deref_ptr"}, + + // Uses the inline word as a pointer, and pushes the byte value at that + // address to the stack. + &Instruction{ 0xB7, 0, 2, 0, "deref_ptr_inline"}, + + // Pushes the inline word to the stack &Instruction{ 0xB8, 0, 2, 0, "push_word"}, &Instruction{ 0xB9, 0, 2, 0, "push_word_indexed"}, &Instruction{ 0xBA, 0, 2, 0, "push"}, &Instruction{ 0xBB, 0, -1, 0, "push_data"}, &Instruction{ 0xBC, 0, 2, 0, "push_string_from_table"}, + + // Pops a byte off the stack and stores it at the inline address. &Instruction{ 0xBD, 0, 2, 0, "pop"}, &Instruction{ 0xBE, 0, 2, 0, "write_to_table"}, &Instruction{ 0xBF, 0, 2, 0, "jump_not_zero"}, + // One byte off stack; jumps to inline if byte is zero &Instruction{ 0xC0, 1, 2, 0, "jump_zero"}, &Instruction{ 0xC1, 1, -2, 0, "jump_switch"}, &Instruction{ 0xC2, 1, 0, 1, "equals_zero"}, &Instruction{ 0xC3, 2, 0, 1, "and_a_b"}, &Instruction{ 0xC4, 2, 0, 1, "or_a_b"}, &Instruction{ 0xC5, 2, 0, 1, "equal"}, + + // Two bytes off stack; result pushed back; 1 if A == B, 0 if A != B &Instruction{ 0xC6, 2, 0, 1, "not_equal"}, &Instruction{ 0xC7, 2, 0, 1, "less_than"}, &Instruction{ 0xC8, 2, 0, 1, "less_than_equal"}, @@ -118,7 +142,10 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0xE0, 2, 0, 1, "signed_divide"}, &Instruction{ 0xE1, 4, 0, 0, ""}, &Instruction{ 0xE2, 7, 0, 0, "setup_sprite"}, - &Instruction{ 0xE3, 1, 0, 1, "get_byte_at_arg_a"}, + + // Pops a word off the stack, uses it as a pointer, and pushes the byte + // value at that address to the stack. + &Instruction{ 0xE3, 1, 0, 1, "deref_ptr_stack"}, &Instruction{ 0xE4, 2, 0, 0, "swap_ram_bank"}, &Instruction{ 0xE5, 1, 0, 0, "disable_sprite"}, &Instruction{ 0xE6, 1, 0, 0, "tape_nmi_setup"}, @@ -129,7 +156,7 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0xEB, 4, 0, 0, ""}, &Instruction{ 0xEC, 2, 0, 0, "scroll"}, &Instruction{ 0xED, 1, 0, 0, "disable_sprites"}, - &Instruction{ 0xEE, 1, -3, 0, "call_switch"}, + &Instruction{ 0xEE, 1, -3, 0, "call_switch"}, &Instruction{ 0xEF, 6, 0, 0, ""}, &Instruction{ 0xF0, 0, 0, 0, "disable_sprites"}, @@ -147,7 +174,9 @@ var Instructions []*Instruction = []*Instruction{ &Instruction{ 0xFC, 2, 0, 1, ""}, &Instruction{ 0xFD, 0, 0, 16, "halt"}, &Instruction{ 0xFE, 4, 0, 0, ""}, - &Instruction{ 0xFF, 0, 0, 0, "break_engine"}, // code handler is $FFFF + + // code handler is $FFFF + &Instruction{ 0xFF, 0, 0, 0, "break_engine"}, } type Instruction struct {