_printf movem.l d0-d3/a0-a4/a6,-(sp) save regs movea.l 44(sp),a3 a3 points to string lea.l 48(sp),a4 a4 points to args lea.l -256(sp),sp make room for output string movea.l sp,a2 a2 points to output string ; The main loop, copy characters to the output buffer until a % or \ is ; encountered in which case interpret the characters following in the same ; manner as C's printf function and put the results into the output stream ; instead. A null byte terminates the output. _printloop move.b (a3)+,d0 get a copy of the byte _possibleend move.b d0,(a2) move to output string beq _printdone terminating byte cmpi.b #'\',d0 special character byte ? beq.s _specialchar yes, go see what it is cmpi.b #'%',d0 number or string byte ? beq.s _introchar yes, go process that _bumpptr addq.l #1,a2 nothing special, bump ptr... bra.s _printloop ...and go back for the next ; Found a backslash, replace character after with tab or newline (\t or \n) _specialchar move.b (a3)+,d0 get the next character beq.s _possibleend that could have been nasty!! cmpi.b #'\',d0 did caller want a backslash beq.s _bumpptr yes, so leave the other cmpi.b #'t',d0 did user want a tab ? bne.s _checkcr nope, maybe a newline move.b #9,(a2)+ yes, store tab and bump bra.s _printloop and go for the next char _checkcr cmpi.b #'n',d0 did user want a newline ? bne.s _printloop nope, ignore all others move.b #13,(a2)+ yes, store cr and bump move.b #10,(a2)+ bra.s _printloop and go for the next char ; Found a percent sign. Must be introducing a number, string or character _introchar move.b (a3)+,d0 get the next character beq.s _possibleend another possible oops! cmpi.b #'%',d0 did caller want a percent? beq.s _bumpptr yes, so leave the last one cmpi.b #'c',d0 print a character ? bne.s _checkstring nope! move.l (a4)+,d0 get char from arg stack move.b d0,(a2)+ store it and bump ptr bra.s _printloop and go for the next char _checkstring cmpi.b #'s',d0 print a string ? bne.s _checknumber nope! movea.l (a4)+,a0 get ptr from arg stack 10$ move.b (a0)+,(a2)+ and copy the string bne.s 10$ subq.l #1,a2 went 1 byte too far bra.s _printloop go for the next char ; wasn't a string or character code so it has to be a number code here _checknumber moveq.l #0,d2 flag, short (word) number cmpi.b #'l',d0 long version of a number ? bne.s _whatnumber no, it was a short moveq.l #1,d2 flag, longword number move.b (a3)+,d0 and get the next letter beq.s _possibleend yet another nasty spot! _whatnumber cmpi.b #'x',d0 hex character ? bne.s _decnumber nope, must be a decimal move.l (a4)+,d0 get hex value to print movea.l a2,a0 buffer to store to tst.w d2 see what size bne.s _dolonghex it's a longword bsr bin2hex16 it's a word bra.s _findend find where number ends _dolonghex bsr bin2hex32 bra.s _findend find where number ends _decnumber cmpi.b #'d',d0 really want a decimal ? bne _printloop nope, illegal character! move.l (a4)+,d0 get decimal value to print movea.l a2,a0 and buffer to store to tst.w d2 see what size bne.s _dolongdec it's a longword bsr bin2asc16 it's a word bra.s _findend see what size _dolongdec bsr bin2asc32 ; A number has been stored into the buffer, find the end to update A2 ptr _findend tst.b (a2)+ search for null byte bne.s _findend not there yet subq.l #1,a2 went one byte too far bra _printloop go for the next char ; We got to the end of the format string and now have a formatted string on ; the stack that is terminated by a null byte. Open the dos library to find ; the current output stream and write the string out. _printdone movea.l 4.w,a6 need exec library node lea.l DosName(pc),a1 moveq.l #0,d0 don't care what version jsr _LVOOpenLibrary(a6) tst.l d0 beq.s _cleanup didn't get the library movea.l d0,a6 jsr _LVOOutput(a6) find output handle move.l d0,d1 where we print to move.l sp,d2 where we print from suba.l sp,a2 find length of string move.l a2,d3 jsr _LVOWrite(a6) and write it out movea.l a6,a1 movea.l 4.w,a6 finished with dos lib now jsr _LVOCloseLibrary(a6) _cleanup lea.l 256(sp),sp fix up the stack pointer movem.l (sp)+,d0-d3/a0-a4/a6 restore regs rts all done bin2asc16 EXT.L D0 make word into a longword bin2asc32 TST.L D0 is it negative ? BPL.S bin2asc nope, call main routine NEG.L D0 make positive MOVE.B #'-',(A0)+ output a minus sign bin2asc MOVEM.L D2-D3/A2-A3,-(SP) MOVEA.L A0,A3 save buffer pointer LEA.L PowersOfTen(PC),A2 powers of ten table MOVEQ.L #0,D1 leading zero flag MOVE.L (A2)+,D2 fetch first power of ten 10$ MOVEQ.L #-1,D3 current digit value 20$ ADDQ.B #1,D3 update this digit SUB.L D2,D0 subtract current pwr of 10 BPL.S 20$ go for another ADD.L D2,D0 fix, we went too far TST.B D3 is this a zero ? BNE.S 30$ no, skip leading zero test TST.W D1 have we put in any digits yet? BEQ.S 40$ no, so scrap this one 30$ MOVEQ.L #1,D1 stop suppressing zeros now ADDI.B #'0',D3 make an ascii digit MOVE.B D3,(A0)+ store it 40$ MOVE.L (A2)+,D2 get next power of 10 BNE.S 10$ do the next bit TST.W D1 did we put any digits in BNE.S 50$ yes MOVE.B #'0',(A0)+ no, put zero as the result 50$ CLR.B (A0) terminate the string MOVE.L A3,D0 retrieve pointer to buffer MOVEM.L (SP)+,D2-D3/A2-A3 RTS PowersOfTen DC.L 1000000000,100000000,10000000,1000000 DC.L 100000,10000,1000,100,10,1,0 bin2hex32 MOVEQ.L #7,D1 generate a longword BRA.S dohex bin2hex16 MOVEQ.L #3,D1 generate a word dohex MOVE.L D2,-(SP) MOVE.L D0,D2 save the value MOVEA.L A0,A1 save buffer address for later CLR.B 1(A0,D1.W) terminate the string 10$ MOVE.B D2,D0 get next nybble ANDI.B #$0F,D0 ADDI.B #'0',D0 make into ascii CMPI.B #'9',D0 BLE.S 20$ no adjustment for letters ADDI.B #('A'-'9')-1,D0 add offset for letters 20$ MOVE.B D0,0(A0,D1.W) store this digit LSR.L #4,D2 move next nybble into place DBRA D1,10$ MOVE.L A1,D0 return address of buffer MOVE.L (SP)+,D2 RTS DosName dc.b 'dos.library',0 even