;fastscan assembly procedure ;its argument is the character to scan for ;it scans to the end of a word but can start in the middle of a word ;to do that set vlb to false before calling ;if char is found: vwdremain, vpw, and vlb will point at it ;if char is not found: vwdremain is set to 0, vpw and vlb are as passed .bext vpw,vlb,vchremain,fastscan,getsintfast .srel fastscan: .fastscan .nrel ; ac0 the char, ac1 mask, ac2 is test word, ac3 buffer pointer .fastscan: sta 3 returnaddr ; save BCPL state sta 2 frameptr lda 3 @.vchremain mov 3 3 snr jmp notfound; lda 1 bytemask lda 3 @.vpw ;in order to save a byteswap operation you test on ;char lshift 8 therefore... movs 0 0 lda 2 @.vlb mov 2 2 szr jmp leftentry jmp rightentry nextword: inc 3 3 leftentry: lda 2 0 3 and 1 2 sub 0 2 snr jmp foundleft dsz @.vchremain; jmp rightentry jmp notfound; rightentry: lda 2 0 3 movs 2 2 and 1 2 sub 0 2 snr jmp foundright dsz @.vchremain; jmp nextword jmp notfound foundright: sub 0 0 skp foundleft: adc 0 0 sta 0 @.vlb sta 3 @.vpw notfound: lda 3 returnaddr lda 2 frameptr jmp 1,3 ; constants .vpw:vpw .vlb:vlb .vchremain:vchremain bytemask: 177400 returnaddr: 0 frameptr: 0 one: 1 .srel getsintfast:.getsintfast .nrel .getsintfast: sta 2 frameptr inc 3 3 sta 3 returnaddr sta 1 pchar isz @.vchremain ; vchremain must reflect rv pchar jmp .+1 lda 2 @.vlb ; be sure vlb is 0 or -1 mov# 2 2 szr adc 2 2 ; it is now -1 for sure sta 2 @.vlb lda 1 @pchar ; first char lda 3 @.vpw jmp entry loop: lda 1 0 3 lda 2 @.vlb com 2 2 snr ; vlb = not vlb movs 1 1 skp ; left byte inc 3 3 ; right byte sta 2 @.vlb lda 2 mask and 2 1 entry: lda 2 nine subz# 1 2 snc ; **?? skip if ac2 ge ac1 jmp exit lda 2 zero subz 2 1 snc ; ** ? subtract, and skip if result ge 0 jmp exit1 movzl 0 2 ; multiply by 10 movzl 2 2 addzl 2 0 add 1 0 ; sum = sum + ... dsz @.vchremain jmp loop adc 1 1 ; char = -1 if ran off end jmp returncode exit1: add 2 1 exit: sta 3 @.vpw dsz @.vchremain ; compensate for initial increment jmp .+1 returncode: sta 1 @pchar lda 2 frameptr jmp @returnaddr mask: 377 nine: 71 zero: 60 pchar: 0 .end