; timer routines ; ; unfortunately the standard Apple 2 has no CIA or VBI, so for the moment, we will ; make each call to 'timer_read' delay for a little while ; this kludge will make the polling loops work at least ; ; timer_read is meant to return a counter with millisecond resolution .include "../inc/common.i" .export timer_init .export timer_read .bss current_time_value: .res 2 .code timer_init: ldax #0 stax current_time_value rts ; return the current value (actually, delay a while, then update current value, then return it in ax) timer_read: lda #111 jsr $fca8 ;wait for about 33ms clc lda #33 adc current_time_value sta current_time_value bcc :+ inc current_time_value+1 : ldax current_time_value rts