Login
Forum Help



Post Your Message
Username: (Login)

Topic:
Message:
 


Previous Messages
Posted By

gerliczer
on 2012-01-15
16:21:03
 Re: ca65 lowbyte

Half an hour later I realized too that the correct address for the .org directive should be $fff. siz was much quicker than me. Another idea would be leaving it as rudis wrote it originally and inserting a
.org *-2
line after the load address word. This works only if the compiler supports such syntax and more than one .org directive in one source.

Posted By

rudis
on 2012-01-15
15:01:10
 Re: ca65 lowbyte

works like a charm now. grin

many thanks

Posted By

siz
on 2012-01-15
14:29:24
 Re: ca65 lowbyte

Gerliczer is right: you put the load address (.word *) after your .org $1001 and that shifts the rest of your code by two bytes.
So you should write:
.org $1001 -2 (which is $fff and not $ffe grin)
.word $1001
...and the rest
Also gerliczer is right in case of the placement of the link label too.

Posted By

gerliczer
on 2012-01-15
14:19:19
 Re: ca65 lowbyte

Is it any better if you try it with
.org $ffe
.word $1001
?
Anyway, I think you should move the label "link" before the line ".byte $00,$00" because the way it is written now makes the basic line linking wrong. At least I think so.

Posted By

rudis
on 2012-01-15
14:03:43
 ca65 lowbyte

played little bit with asm

--8<---

.setcpu "6502"
.org $1001
.word *

.word link
.word 2012 ; zeilennummer
.byte $9e ; sys-token
.byte "4109" ; adresse
.byte $00 ; zeilenende
.byte $00,$00
link:
sei
ldx #<myvbl-2
stx $312
ldx #>myvbl
stx $313
cli
rts

myvbl:
inc $ff19
jmp $ce42

jsr $fff6

-->8--

so if i don't write
ldx #<myvbl-2  

but
ldx #<myvbl

the adress is 2 bytes to high. WHY???


Copyright © Plus/4 World Team, 2001-2024. Support Plus/4 World on Patreon