Help me find this bug please

[Frozone212]

I keyed in the entirety of Alfabug from Compute gazette issue 01 and managed to squash all but line 34 which is a bit of a headscratcher. I entered the data exactly so I don't know what could be wrong.

 

anyone have any ideas?

here is the listing:

Compute Gazette Issue 01 : Free Download, Borrow, and Streaming : Internet Archive

page 121

 

Edited January 21, 2023 by Frozone212

[+evg2000]

without seeing your code it's hard to debug, but I typed in the two lines and add a third to test and it worked fine for me.  I think you must have a typo.
alfabuglines.PRG

[Frozone212]

10 hours ago, evg2000 said:

without seeing your code it's hard to debug, but I typed in the two lines and add a third to test and it worked fine for me.  I think you must have a typo.
alfabuglines.PRG

i can't list it all but I can give the d64 image so here

it's for the vic 20

alfabug.d64

[carlsson]

It says FORI=0TO15 but you have typed FORI=0TO16 which means it tries to read one DATA statement more than intended. Also it should say 41*8 but you typed in 41*2.

 

Also you have one DATA statement too few on line 36:

36 DATA 36,72,123,254,123,72,36,144,72,123,254,254,123,72,144

 

should be:

36 DATA 36,72,123,254,254,123,72,36,144,72,123,254,254,123,72,144

 

Line 57 should be X=7812, you have written X=7182.

 

Line 78 should have a HOME symbol (inverted capital S), not CLR symbol (inverted heart). Same about line 120.

There are also two skipped spaces on line 78 between PRESS and the CHR$(18) and between CHR$(146) and TO but that is mostly cosmetic.

 

You have omitted lines 102 and 105.

You have omitted line 118, which returns graphics to normal text.

 

I see that the REM statement on line 76 is optional. You left out the REM, which means the program will randomly ask you for a letter to press instead of in sequence.

Yes, this is a program intended for 3-6 years old to learn the alphabet.

Edited January 22, 2023 by carlsson

[carlsson]

Here is the D64 with a fixed version, which I believe is according to the listing.

alfabug.d64

[Frozone212]

thank you