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indent code for readability
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user3840170
user3840170
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I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

      ORG $300
HOME  EQU $FC58
CTR   EQU $06
COUT  EQU $FDED

START JSR HOME
      LDA #$FF
      STA CTR
LOOP  LDA CTR
      JSR COUT
      DEC CTR
      BEQ END
      JMP LOOP
END   RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

ORG $300
HOME EQU $FC58
CTR EQU $06
COUT EQU $FDED

START JSR HOME
LDA #$FF
STA CTR
LOOP LDA CTR
JSR COUT
DEC CTR
BEQ END
JMP LOOP
END RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

      ORG $300
HOME  EQU $FC58
CTR   EQU $06
COUT  EQU $FDED

START JSR HOME
      LDA #$FF
      STA CTR
LOOP  LDA CTR
      JSR COUT
      DEC CTR
      BEQ END
      JMP LOOP
END   RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

fixed a few typos from where I transcribed code off my Apple II
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Eric Noble
Eric Noble
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I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

ORG $300
HOME EQU $FC58
CTR EQU $06
COUT EQU #FDBD$FDED

START JSR HOME
LDA #$FF
STA CTR
LOOP LDA CTR
JSR COUT
DEC CTR
BEQ END
JMP LOOP
END RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

ORG $300
HOME EQU $FC58
CTR EQU $06
COUT EQU #FDBD

START JSR HOME
LDA #$FF
STA CTR
LOOP LDA CTR
JSR COUT
DEC CTR
BEQ END
JMP LOOP
END RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

ORG $300
HOME EQU $FC58
CTR EQU $06
COUT EQU $FDED

START JSR HOME
LDA #$FF
STA CTR
LOOP LDA CTR
JSR COUT
DEC CTR
BEQ END
JMP LOOP
END RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!

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Eric Noble
Eric Noble
  • 121
  • 4

Apple IIe Enhanced not following BEQ correctly

I'm running the example code from Assembly Lines chapter 5 programs 2A and 2B which print the entire character map for the Apple II and then are supposed to break, however my code is looping permanently. Here is the code:

ORG $300
HOME EQU $FC58
CTR EQU $06
COUT EQU #FDBD

START JSR HOME
LDA #$FF
STA CTR
LOOP LDA CTR
JSR COUT
DEC CTR
BEQ END
JMP LOOP
END RTS

I have double checked the book and don't think I mistyped anything but the program just loops over and over, almost like the zero flag isn't ever properly set. I know the zero flag works for dex and dey because I've used those for loop counters in prior exercises.

Thanks!