1987: Kid submits 7 Robotron bugfixes using only the machine code from the ROMs

Re:1987: Kid submits 7 Robotron bugfixes using only the mach... by geocar on Wednesday July 10, 2013 @03:58PM (#6022406)

The Apple II had a monitor you could reach via:

    ]CALL -151

and you could type a program such as:

    *300:AD 30 C0 88 D0 FD 4C 00 30

but while there was a disassembler (300 L) there was no assembler!

Fortunately, if you had Integer Basic, you could do:

    ]INT

to get to Integer basic, then go into that monitor:

    >CALL -151

then jump into the "mini assembler" inside Integer Basic:

    *F666 G

and now you're in something resembling an assembler:

    !300:LDY#$0
    !302:JMP$309
    !305:JSR$FDED
    !308:INY
    !309:LDA $320,Y
    !30C:BNE $305
    !30E:JMP$FF65
    !$320:48 45 4c 4c 4f 20 48 41 
    !$328:43 4b 45 52 20 4e 45 57 
    !$330:53 21 00
    !303G

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Re:1987: Kid submits 7 Robotron bugfixes using only the mach... by gamache on Thursday July 11, 2013 @07:52AM (#6025500)

  *300:AD 30 C0 88 D0 FD 4C 00 30

OWWW my ears! And I think you meant "4C 00 03" there. :)

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Re:1987: Kid submits 7 Robotron bugfixes using only the mach... by geocar on Thursday July 11, 2013 @01:33PM (#6027581)

Yup definitely. Good catch!

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Re:1987: Kid submits 7 Robotron bugfixes using only the mach... by joezydeco on Wednesday July 10, 2013 @05:15PM (#6022886)

Nicely explained. And hello back at ya. (JSR $FF3A)

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