Difference between revisions of "Talk:83Plus:BCALLs:4B73"
From WikiTI
| Line 3: | Line 3: | ||
Code is: | Code is: | ||
| − | ld hl,(965D) | + | ld hl,(965D) \ |
| − | inc hl | + | inc hl \ |
| − | ld (965D),hl | + | ld (965D),hl \ |
| − | ld bc,(965D) | + | ld bc,(965D) \ |
| − | ld hl,(965F) | + | ld hl,(965F) \ |
| − | xor a | + | xor a \ |
| − | sbc hl,bc | + | sbc hl,bc \ |
| − | ret c | + | ret c \ |
| − | ld a,(bc) | + | ld a,(bc) \ |
| − | ret | + | ret |
...This makes it looks like A) It's the new byte, not the old once, since it's read after (965D) is incremented, and B) That the value of A is only set if we're not at the end of the buffer, which should be noted in the output description. | ...This makes it looks like A) It's the new byte, not the old once, since it's read after (965D) is incremented, and B) That the value of A is only set if we're not at the end of the buffer, which should be noted in the output description. | ||
--Dan | --Dan | ||
Latest revision as of 20:30, 27 March 2005
A is the byte NextParseByte was pointing to, unless the comparison between 965D and 965F carries, in which case a is returned as zero. This should be addressed in the output information for register A, but I don't know exactly what it's doing (which is why I left it blank originally).
- Actually, that does not appear to be the case. The value returned is the data at the new pointer value. I believe that 83Plus:RAM:965F holds the end of the program/equation being run, so the routine returns with carry set if you're at the end of the program. FloppusMaximus 19:24, 27 Mar 2005 (PST)
Code is: ld hl,(965D) \ inc hl \ ld (965D),hl \ ld bc,(965D) \ ld hl,(965F) \ xor a \ sbc hl,bc \ ret c \ ld a,(bc) \ ret
...This makes it looks like A) It's the new byte, not the old once, since it's read after (965D) is incremented, and B) That the value of A is only set if we're not at the end of the buffer, which should be noted in the output description. --Dan
