diff options
| author | B. Watson <yalhcru@gmail.com> | 2015-12-29 23:10:50 -0500 |
|---|---|---|
| committer | B. Watson <yalhcru@gmail.com> | 2015-12-29 23:10:50 -0500 |
| commit | 2300d2813a524cbfeabac794335e7abe99263df6 (patch) | |
| tree | d729ca4f99634788cbb3a2101a5b5854a4bc2d06 /timed_getch.s | |
| download | taipan-2300d2813a524cbfeabac794335e7abe99263df6.tar.gz | |
initial commit
Diffstat (limited to 'timed_getch.s')
| -rw-r--r-- | timed_getch.s | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/timed_getch.s b/timed_getch.s new file mode 100644 index 0000000..8675290 --- /dev/null +++ b/timed_getch.s @@ -0,0 +1,26 @@ + + .export _timed_getch, _set_jiffy_timer + .import _cgetc + +_set_jiffy_timer: + sei + sta 540 + stx 541 + cli + rts + +_timed_getch: + jsr _set_jiffy_timer +wait4key: + lda 540 + ora 541 + beq done + ldx 764 + inx + beq wait4key + jmp _cgetc + +done: + lda #$ff ; return -1 + tax + rts |