; CopyDiskUtilA.asm ; Copyright Xerox Corporation 1979, 1980 ; Last modified April 16, 1980 3:13 AM by Boggs .ent UBlockEq .ent BlockEq .ent UPupChecksum .ent MulDiv .ent DoubleUsc .ent MulPlus32x16 .ent Divide32x16 .srel UBlockEq: .UBlockEq BlockEq: .BlockEq UPupChecksum: .UPupChecksum MulDiv: .MulDiv DoubleUsc: .DoubleUsc MulPlus32x16: .MulPlus32x16 Divide32x16: .Divide32x16 .nrel ; UBlockEq(adr1,adr2,count) - Microcode version ; Compare the count words starting at adr1 with the corresponding ; words starting at adr2, and return true iff all the corresponding ; words are equal. .UBlockEq: sta 3 1,2 lda 3 3,2 ; get count 63000 ; call microcode mov 3 3 szr ; ac3 = 0 if all is well sub 0 0 skp adc 0 0 lda 3 1,2 jmp 1,3 ; BlockEq(adr1,adr2,count) - Assembly language version ; Compare the count words starting at adr1 with the corresponding ; words starting at adr2, and return true iff all the corresponding ; words are equal. .BlockEq: sta 3 1,2 sta 0 2,2 ; Store adr1 mov 1 3 ; ac3 _ adr2 ; Compare the first (count mod 8) words one at a time bleq1: lda 0 3,2 ; See if count mod 8 = 0 lda 1 c7 and# 0 1 snr jmp bleq2 ; Yes, go to fast loop lda 0 @2,2 ; No, do slow compare of one word lda 1 0,3 se 0 1 jmp bleq5 ; Not equal, return false isz 2 2 ; Equal, increment addresses inc 3 3 dsz 3,2 ; Decrement and test count jmp bleq1 ; Set up for fast loop bleq2: lda 0 3,2 ; Compute count/8 movzr 0 0 movzr 0 0 movzr 0 0 snr jmp bleq4 ; Less than 8 words in block sta 0 3,2 ; Store count/8 lda 0 2,2 ; Get current adr1 ; Fast loop. ac0/ adr1, ac3/ adr2, count in frame temp 3. ; The portion inside dir...eir is non-reentrant due to the use ; of save2. bleq3: dir ; Interlock non-reentrant portion sta 2 save2 ; Save frame pointer mov 0 2 ; ac2 _ adr1 lda 0 0,2 ; Compare 8 words, to bleq6 if fail lda 1 0,3 se 0 1 jmp bleq6 lda 0 1,2 lda 1 1,3 se 0 1 jmp bleq6 lda 0 2,2 lda 1 2,3 se 0 1 jmp bleq6 lda 0 3,2 lda 1 3,3 se 0 1 jmp bleq6 lda 0 4,2 lda 1 4,3 se 0 1 jmp bleq6 lda 0 5,2 lda 1 5,3 se 0 1 jmp bleq6 lda 0 6,2 lda 1 6,3 se 0 1 jmp bleq6 lda 0 7,2 lda 1 7,3 se 0 1 jmp bleq6 lda 0 c10 add 0 3 ; Increment adr2 by 8 add 2 0 ; Increment adr1 by 8, move to ac0 lda 2 save2 ; Recover frame pointer eir ; Now reentrant dsz 3,2 ; Decrement and test count jmp bleq3 ; More to do bleq4: mkminusone 0 0 skp ; Here to return true bleq5: mkzero 0 0 ; Here to return false lda 3 1,2 jmp 1,3 bleq6: lda 2 save2 ; Here to return false when eir ; inside fast loop jmp bleq5 c7: 7 c10: 10 save2: 0 ; PupChecksum microcode interface ; microcoded replacement for PupChecksum procedure in PupAl1a.asm .UPupChecksum: sta 3 1,2 mov 0 1 ; address in AC1 for microcode mov 0 3 lda 3 0,3 ; get pup length in bytes neg 3 3 ; compute # words exclusive of checksum comzr 3 3 ; = (# bytes -1)/2 mkzero 0 0 ; init checksum 63400 ; call microcode lda 3 1,2 jmp 1,3 ; MulDiv(a, b, c) ; returns the unsigned value (a*b)/c .MulDiv: sta 3 1,2 mov 2 3 mov 0 2 mkzero 0 0 mul lda 2 3,3 div 77400 mov 1 0 mov 3 2 lda 3 1,2 jmp 1,3 ; MulPlus32x16(addend,multiplier,lvMultiplicand) ; lvMultiplicand = lvMultiplicand*multiplier + addend (all unsigned) ; lvMultiplicand is 32 bits, multiplier and addend are 16 bits. ; returns the overflow .MulPlus32x16: sta 3 1,2 ; save return in frame mov 2 3 ; vacate AC2. AC3_ frame sta 1 2,3 ; save multiplier in frame lda 2 3,3 ; AC2_ lvMultiplicand lda 2 1,2 ; AC2_ lvMultiplicand!low mul lda 2 3,3 ; AC2_ lvMultiplicand sta 1 1,2 ; store low result lda 2 0,2 ; AC2_ lvMultiplicand!high lda 1 2,3 ; AC1_ multiplier mul sta 1 @3,3 ; store high result mov 3 2 ; restore frame lda 3 1,2 ; return jmp 1,3 ; overflow in AC0 ; DoubleUsc(lvA, lvB) = -1|0|1 ; Returns: -1 if A < B ; 0 if A = B ; 1 if A > B ; lvA and lvB are the addresses of the 32 bit operands .DoubleUsc: sta 0 3,2 ; lvA sta 1 2,2 ; lvB lda 0 @3,2 ; A high part lda 1 @2,2 ; B high part se 0 1 ; A, B jmp dusc1 isz 3 2 ; lvA isz 2 2 ; lvB lda 0 @3,2 ; A low part lda 1 @2,2 ; B low part dusc1: sleu 0 1 ; A, B jmp gr ; A > B se 0 1 ; A, B mkminusone 0 0 skp ; A < B mkzero 0 0 ; A = B jmp 1,3 gr: mkone 0 0 jmp 1,3 ; Divide32x16(lvNumber, divisor) = ; unsigned divide the 32-bit number at @lvNumber, ; put the quotient back in @lvNumber, and return the remainder. .Divide32x16: sta 3 1,2 ; return mov 2 3 ; save stack pointer sta 0 2,3 ; lvNumber sta 1 3,3 ; divisor mkzero 0 0 lda 1 @2,3 ; get high dividend lda 2 3,3 ; get divisor div ; ac0 _ remainder, ac1 _ quotient nop sta 1 @2,3 ; store high quotient isz 2,3 lda 1 @2,3 ; get low divident div ; ac0 _ remainder, ac1 _ quotient nop sta 1 @2,3 ; store low result mov 3 2 ; restore stack pointer lda 3 1,2 jmp 1,3 .end