So here's a version that changes the procedure that prints the stack into a function, so we can call it from within an expression:and the result of running it:What happens if we use USR to call the stack printing? For this version I will include the full program because I have added some code to the assembler to print the 'S=' and 'BSP=' labels. That way we don't need to call a BASIC PRINT statement from the middle of an expression.This shows how the highly nested brackets have push a lot onto the machine stack. In the earlier example, when we called a BASIC FN from within the expression, the FN/PROC call mechanism had moved much of that to the BASIC stack.
Code:
680 NEXT 690 PRINT 1+(2*(3-(4/(5+(6*(7-(8+(10+(12/(1+FNstack)))))))))) 700 END 710 DEF FNstack 720 PRINT '"S="; 730 CALL pstack 740 PRINT '"BSP="; 750 CALL bstack 760 =1Code:
10 REM > STACK2 20 OSWRCH=&FFEE 30 OSNEWL=&FFE7 40 DIM C% 200 50 FOR N%=0 TO 3 STEP 3 60 P%=C% 70 [OPT N% 80 .hexout 90 PHA 100 LSR A 110 LSR A 120 LSR A 130 LSR A 140 JSR hexnyb 150 PLA 160 AND #&0F 170 .hexnyb 180 CMP #10 190 BCC hexskp 200 ADC #&06 210 .hexskp 220 ADC #&30 230 JMP OSWRCH 240 .pstack 250 LDA #ASC("S") 260 JSR OSWRCH 270 LDA #ASC("=") 280 JSR OSWRCH 290 TSX 300 TXA 310 JSR hexout 320 JSR OSNEWL 330 INX 340 BEQ stkdone 350 .stkloop 360 LDA &0100,X 370 JSR hexout 380 LDA #&20 390 JSR OSWRCH 400 INX 410 BNE stkloop 420 .stkdone 430 JMP OSNEWL 440 .both 450 JSR pstack 460 .bstack 470 LDA #ASC("B") 480 JSR OSWRCH 490 LDA #ASC("S") 500 JSR OSWRCH 510 LDA #ASC("P") 520 JSR OSWRCH 530 LDA #ASC("=") 540 JSR OSWRCH 550 LDA &05 560 STA &71 570 JSR hexout 580 LDA &04 590 STA &70 600 JSR hexout 610 JSR OSNEWL 620 LDY #&00 630 .bloop 640 LDA &70 650 CMP &06 660 BNE bcont 670 LDA &71 680 CMP &07 690 BEQ bdone 700 .bcont 710 LDA (&70),y 720 JSR hexout 730 LDA #&20 740 JSR OSWRCH 750 INC &70 760 BNE bloop 770 INC &71 780 BNE bloop 790 .bdone 800 JMP OSNEWL 810 ] 820 NEXT 830 PRINT 1+(2*(3-(4/(5+(6*(7-(8+(10+(12/(USRboth)))))))))) 840 ENDStatistics: Posted by Coeus — Sat Feb 15, 2025 12:34 am