As a comparison, I thought I'd check out Z80 BBC BASIC. Here's the Z80 version of the last program, the one with all the brackets:This version prints the stack contents as 16-bit words as all the Z80 PUSH and POP instructions work with 16-bit words. Here's the result of running it:and here is a revised tail for the recursive function call with passed parameter:which gives this output:This looks to me to be using the machine stack for more and has probably dispensed with the separate stack for BASIC. The Z80 has a 16-bit stack point so the stack is not restricted to 256 bytes and can grow down from HIMEM while the program and variables grow up from PAGE.
Code:
10 OSWRCH=&FFEE 20 OSNEWL=&FFE7 30 DIM C% 200 40 FOR N%=0 TO 3 STEP 3 50 P%=C% 60 [OPT N% 70 .hexout 80 LD C,A 90 RRA 100 RRA 110 RRA 120 RRA 130 CALL hexnyb 140 LD A,C 150 .hexnyb 160 AND &0F 170 ADD A,&90 180 DAA 190 ADC A,&40 200 DAA 210 JP OSWRCH 220 .pstack 230 LD A,&53 240 CALL OSWRCH 250 LD A,&50 260 CALL OSWRCH 270 LD A,&3D 280 CALL OSWRCH 290 LD HL,&0000 300 ADD HL,SP 310 LD DE,&DC00 320 LD A,H 330 CALL hexout 340 LD A,L 350 CALL hexout 360 CALL OSNEWL 370 .ploop 380 LD A,D 390 CP H 400 JR NZ,pcont 410 LD A,E 420 CP L 430 JR Z,pdone 440 .pcont 450 LD B,(HL) 460 INC HL 470 LD A,(HL) 480 INC HL 490 CALL hexout 500 LD A,B 510 CALL hexout 520 LD A,&20 530 CALL OSWRCH 540 JR ploop 550 .pdone 560 JP OSNEWL 570 ] 580 NEXT 590 PRINT 1+(2*(3-(4/(5+(6*(7-(8+(10+(12/(USRpstack))))))))))Code:
590 PROCrecurse(0) 600 END 610 DEF PROCrecurse(R%) 620 IF R%=10 CALL pstack ELSE PROCrecurse(R%+1) 630 ENDPROCStatistics: Posted by Coeus — Mon Feb 17, 2025 1:00 am
