diff options
| -rw-r--r-- | conio/README | 15 | ||||
| -rw-r--r-- | timed_getch.s | 23 |
2 files changed, 27 insertions, 11 deletions
diff --git a/conio/README b/conio/README index d2ba1c7..bfe8187 100644 --- a/conio/README +++ b/conio/README @@ -1 +1,16 @@ This is a modified conio. It doesn't draw a cursor at all. + +More particularly, the standard cc65 conio always draws a cursor, whether +the cursor is enabled or not. When it's disabled, the cursor is drawn +as a space character. + +Benefits of doing this: + +- Faster and smoother screen updates +- Slightly smaller code (20-30 bytes) +- No more "cursor ghosts" at timed prompts +- No need for a hide_cursor() function + +Disadvantage: Have to draw the cursor myself when needed. It turns out +that only agetc() needs to do this, so not a big deal. Also had to +add an agetc_no_cursor() for timed_getch() to use. diff --git a/timed_getch.s b/timed_getch.s index c996438..40a2722 100644 --- a/timed_getch.s +++ b/timed_getch.s @@ -38,11 +38,16 @@ _timed_getch: lda #$2c ; $012c jiffies = 5 sec (NTSC) or 6 sec (PAL) ldx #$01 jsr _set_jiffy_timer + @wait4key: lda CDTMV3 ; has timer counted down to 0? ora CDTMV3+1 - beq @done ; yes, return(0) - lda CH ; no, check for a keypress + bne @timer_running + tax ; timer expired, return(0), A is already 0 here + rts + +@timer_running: + lda CH ; no, check for a keypress ; ...but don't let the capslock or inverse keys count ; as a keypress, here. @@ -54,13 +59,7 @@ _timed_getch: cmp #$27 ; inverse (atari) key beq @wait4key - jmp _agetc_no_cursor ; user hit a key, read it. - -@done: - ;lda #$00 ; return(0), A is already 0 here - tax - rts - + ; user hit a key, handle it. but don't print a cursor. _agetc_no_cursor: jsr _cgetc jmp finish_agetc @@ -71,12 +70,14 @@ _agetc_no_cursor: ; (such as clear, delete, escape) are replaced with a space. ; extern unsigned char agetc(void); _agetc: - lda #$80 ; inverse space + ; show the user a cursor + lda #$80 ; inverse space (putchar uses screen codes) jsr putchar jsr _cgetc ; get ATASCII code of keypress - pha + + ; get rid of the cursor lda #$00 ; space jsr putchar pla |