yagsdisasm - Yet Another GS Disassembler

yagsdisasm is written in PHP, which may be an unfortunate choice of languages to many, but is nearly-universally available and makes for a product that's easy to modify, when written properly.

the disassembly engine is largely inspired by Andy McFadden's Ciderpress disassembly engine, which is why we copy his license terms in LICENSE.txt

as of 5/27/2016, the project is gaining features such as processor flag tracking and more vector recognition, but still has a ways to go

Example Run:

$ php yagsdisasm.php -f ~/Downloads/GATE/The\ Gate\ Dk1.2mg -s0 -n1 -k1 -m1 -x1 -e1 -o801 | more
                      ORG 000801
                      MX %11

000801-   EE F4 03    INC 03F4
000804-   9C 34 C0    STZ C034            ; rw:CLOCKCTL [+border color]
000807-   9C 22 C0    STZ C022            ; rw:TBCOLOR
00080A-   EA          NOP
00080B-   EA          NOP
00080C-   EA          NOP
00080D-   EA          NOP
00080E-   AD 10 C0    LDA C010            ; r:KBDSTRB
000811-   8D 00 C0    STA C000            ; r:KBD  w:CLR80COL
000814-   8D 0C C0    STA C00C            ; w:CLR80VID
000817-   9C 12 0E    STZ 0E12
00081A-   AF 20 0F E1 LDA E10F20
00081E-   8D 10 0E    STA 0E10
000821-   AF 21 0F E1 LDA E10F21
000825-   F0 07       BEQ 082E {+07}
000827-   4F 20 0F E1 EOR E10F20
00082B-   8D 12 0E    STA 0E12
00082E-   18          CLC
00082F-   FB          XCE
000830-   C2 30       REP #30
000832-   A9 80 FE    LDA #FE80
000835-   8F 70 00 E1 STA E10070          ; Break vector
000839-   A2 00 00    LDX #0000
00083C-   A9 A0 A0    LDA #A0A0
00083F-   9D 00 04    STA 0400,X
000842-   E8          INX
000843-   E8          INX
000844-   E0 00 04    CPX #0400
000847-   90 F3       BCC 083C {-0D}
000849-   A2 00 A0    LDX #A000
00084C-   CA          DEX
00084D-   CA          DEX
00084E-   9E 00 20    STZ 2000,X
000851-   D0 F9       BNE 084C {-07}
000853-   E2 30       SEP #30
000855-   A9 00       LDA #00
000857-   8D 22 C0    STA C022            ; rw:TBCOLOR
00085A-   A9 00       LDA #00
00085C-   8D 34 C0    STA C034            ; rw:CLOCKCTL [+border color]
00085F-   C2 30       REP #30
000861-   A2 00 00    LDX #0000
000864-   A9 00 00    LDA #0000
000867-   9F 00 7E E1 STA E17E00,X
00086B-   E8          INX
00086C-   E8          INX
00086D-   E0 00 01    CPX #0100
000870-   D0 F5       BNE 0867 {-0B}
000872-   E2 30       SEP #30
000874-   20 80 09    JSR 0980
000877-   A9 14       LDA #14
000879-   8D 78 09    STA 0978
00087C-   9C 79 09    STZ 0979
00087F-   E2 30       SEP #30
000881-   38          SEC
000882-   FB          XCE
000883-   20 0D C5    JSR C50D            ; SmartPort Entry
000886-   41          DB  41              ; Call Number
000887-   6E 09       DW  096E            ; Pointer to parameters
000889-   00          BRK
00088A-   00          BRK
00088B-   B0 F6       BCS 0883 {-0A}
00088D-   18          CLC
00088E-   FB          XCE
00088F-   C2 30       REP #30
000891-   EE 71 09    INC 0971
000894-   EE 71 09    INC 0971
000897-   EE 74 09    INC 0974
00089A-   CE 78 09    DEC 0978
00089D-   D0 E0       BNE 087F {-20}
00089F-   8B          PHB
0008A0-   F4 00 00    PEA 0000
0008A3-   F4 01 00    PEA 0001
0008A6-   F4 00 0A    PEA 0A00
0008A9-   F4 10 00    PEA 0010
0008AC-   F4 1E 00    PEA 001E
0008AF-   22 00 A5 00 JSL 00A500
0008B3-   22 00 0A 01 JSL 010A00
0008B7-   18          CLC
0008B8-   FB          XCE
0008B9-   C2 30       REP #30
0008BB-   8B          PHB
0008BC-   F4 00 00    PEA 0000
0008BF-   F4 01 00    PEA 0001
0008C2-   F4 00 9E    PEA 9E00
0008C5-   F4 01 00    PEA 0001
0008C8-   F4 41 00    PEA 0041
0008CB-   22 00 96 00 JSL 009600
0008CF-   8B          PHB
0008D0-   F4 01 00    PEA 0001
0008D3-   F4 07 00    PEA 0007
0008D6-   F4 00 20    PEA 2000
0008D9-   F4 12 00    PEA 0012
0008DC-   F4 2E 00    PEA 002E
0008DF-   22 00 96 00 JSL 009600
0008E3-   A9 20 20    LDA #2020
0008E6-   A0 10 00    LDY #0010
0008E9-   A2 00 00    LDX #0000
0008EC-   9F 00 9D E1 STA E19D00,X