0100 ; BASIC PROFILER SOURCE CODE›0110 ; BY STAN LACKEY›0120 ; (c)1988, ANTIC PUBLISHING INC.›0150 ;›0160 ; Definitions:›0180 TEMP1 = $CB     ; Temps used in                         routines›0190 TEMP2 = $CD›0200 TEMP3 = $CF›0210 STMCUR = 138    ;  Pointer into                         user program›0220 RAMTOP = 106›0250 ;›0260     *=  $9F00›0270 ;›0280 PROFEN›0285     .BYTE 0     ; Flag to enable                        Profiler›0290 ;›0300 ;  SAMPLE is the timer interrupt›0310 ; routine. It takes the current›0320 ; line number, divides it by 10›0330 ; and increments that 16-bit›0340 ; location in the RAM above›0345 ; RAMTOP.›0350 ;›0360 SAMPLE›0365     LDA PROFEN  ; Sense enable›0370     BNE SPL1›0375 ;›0380     PLA         ; It's off...›0390     RTI         ; just return.›0395 ;›0400 SPL1›0401     TYA ›0410     PHA         ; Must save Y›0420     LDY #0›0430     LDA (STMCUR),Y ; Get line #›0440     STA TEMP1›0450     INY         ; Point to high›0460     LDA (STMCUR),Y›0470     STA TEMP1+1›0480     BMI EXIT    ; Exit if line›0490 ;                 num is neg.›0500 ; Now, divide line number by 10›0510     LDA # <20480 ; Divisor:›0520     STA TEMP2   ;  #10, Shifted›0530     LDA # >20480›0540     STA TEMP2+1›0550     LDA #0›0560     STA TEMP3   ; Clear quotient›0570     STA TEMP3+1›0580     LDY #11     ; Loop count›0590 DIVLP›0595     SEC ›0600     LDA TEMP1›0610     SBC TEMP2›0620     STA TEMP4   ; 16-bit subtr,›0630     LDA TEMP1+1 ; ddnd-dvsr›0640     SBC TEMP2+1›0650     STA TEMP4+1›0660     CLC         ; Init.›0670     BMI NOBIT   ; Shift 0 in›0680 ;                 dvsr > ddnd›0690     LDA TEMP4›0700     STA TEMP1   ; ddnd > dvsr›0710     LDA TEMP4+1 ; Copy new ddnd›0720     STA TEMP1+1›0730     SEC         ; Shift 1 in›0740 NOBIT›0745     ROL TEMP3   ; Shift into›0750     ROL TEMP3+1 ;  quotient›0760     LSR TEMP2+1 ; Shift dvsr›0770     ROR TEMP2›0780     DEY ›0790     BPL DIVLP   ; Loop next bit›0795 ;›0800 ; Result is left in TEMP3.›0810 ; Add that result to RAMTOP.›0820     ASL TEMP3   ; 2x result for›0830     ROL TEMP3+1 ; 2-byte access›0840     CLC ›0850     LDA TEMP3+1›0860     ADC RAMTOP  ; TEMP3 is now›0870     ADC #4      ; the pointer›0880     STA TEMP3+1 ; into the RAM.›0890     LDY #0›0900     CLC ›0910     LDA (TEMP3),Y ; Get cell to›0920     ADC #1      ; increment›0930     STA (TEMP3),Y›0940     BNE EXIT    ; If inc. to 0,›0945 ;›0950     INY ›0960     CLC ›0970     LDA (TEMP3),Y ; incr high›0980     ADC #1      ;   half›0990     STA (TEMP3),Y›1000     BPL EXIT    ; Test overflow›1005 ;›1010     LDA #0      ; Stop prof›1020     STA PROFEN  ; on overflow›1030 EXIT›1035     PLA ›1040     TAY         ; Restore Y›1050     PLA         ;  and A›1060     RTI         ; End of SAMPLE›1065 ;›1070 TEMP4›1075     .WORD 0     ; Temp used in division›