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Assembly Source File | 1984-04-29 | 17.9 KB | 599 lines

; ; 8008 BINARY FLOATING POINT SYSTEM ; ; FORMAT CONVERSION PACKAGE ; ; ; THE FORMAT CONVERSION PACKAGE OF THE 8008 BINARY FLOATING ; POINT SYSTEM CONTAINS SUBROUTINES FOR THE CONVERSION OF ; DATA BETWEEN THE FLOATING POINT SYSTEM NOTATION AND TWO OTHER ; FORMATS. THE NON-FLOATING-POINT FORMATS ARE: FOUR WORD FIXED ; POINT FORMAT AND VARIABLE LENGTH CHARACTER STRING FORMAT. ; ; THE FORMAT CONVERSION PACKAGE IS CONTAINED IN 512 CONSECUTIVE ; WORDS OF MEMORY (2 BANKS OF ROM) AND REQUIRES FOR ITS ; EXECUTION THAT THE ARITHMETIC AND UTILITY PACKAGE BE ; AVAILABLE IN MEMORY. THE COMBINATION OF THIS PACKAGE AND THE ; ARITHMETIC AND UTILITY PACKAGE USES THE FIRST 64 WORDS ; OF A BANK OF RAM AS SCRATCHPAD MEMORY. ; ; ; THE FIXED POINT FORMAT DATA PROCESSED BY THIS PACKAGE ; CONSIST OF 32 BIT BINARY NUMBERS OCCUPYING FOUR WORDS. ; 2'S COMPLEMENT NOTATION IS USED TO REPRESENT NEGATIVE ; VALUES. ; THE POSITION OF THE BINARY POINT RELATIVE TO THE ; BITS REPRESENTING THE VALUE IS DENOTED BY A BINARY ; SCALING FACTOR. THE BINARY SCALING FACTOR IS NOT NORMALLY ; RECORDED IN THE COMPUTER, BUT WHEN A FORMAT CONVERSION ; SUBROUTINE IS CALLED, THE BINARY SCALING FACTOR MUST BE ; SPECIFIED (IN THE E REGISTER). A BINARY SCALING FACTOR OF ; ZERO INDICATES THAT THE BINARY POINT IS IMMEDIATELY TO THE ; LEFT OF THE MOST SIGNIFICANT OF THE 32 BITS REPRESENTING THE ; VALUE. A BINARY SCALING FACTOR OF 32 INDICATES THAT THE BINARY ; POINT IS IMMEDIATELY TO THE RIGHT OF THE LEAST SIGNIFICANT ; BIT. THE PERMISSIBLE RANGE OF THE BINARY SCALING FACTOR IS ; -128 (200 OCTAL) TO +127 (177 OCTAL). ; ; ; THE CHARACTER STRING FORMAT DATA PROCESSED BY THIS PACKAGE ; CONSIST OF BINARY REPRESENTATIONS OF CHARACTERS OCCUPYING ; CONSECUTIVE WORDS OF MEMORY. A CHARACTER STRING MAY NOT ; CROSS A MEMORY BANK BOUNDARY. THE CHARACTERS WHICH MAY BE ; INCLUDED IN A CHARACTER STRING, AND THE CORRESPONDING ; OCTAL REPRESENTATIONS ARE LISTED BELOW. ; ; DECIMAL DIGITS 000B-011B BCD DIGITS ; SPACE 360B ; + 373B PLUS ; - 375B MINUS ; . 376B DECIMAL POINT ; E 25QB EXPONENTIAL SIGN ; (THESE OCTAL REPRESENTATIONS CAN BE CONVERTED TO THE ; CORRESPONDING ASCII CHARACTERS BY ADDING 60 OCTAL TO EACH ; ; THE OUT SUBROUTINE GENERATES CHARACTER STRINGS IN TWO ; FORMATS, EACH CONSISTING OF 13 CHARACTERS. THE FORMAT ; USED IN A SPECIFIC CASE IS DEPENDENT ON THE MAGNITUDE ; OF THE VALUE REPRESENTED. ; ZERO AND MAGNITUDES BETWEEN .1000000 AND 9999999. ARE ; REPRESENTED BY A SPACE OR MINUS SIGN, SEVEN DECIMAL DIGITS, ; AN APPROPRIATELY POSITIONED DECIMAL POINT, AND FOUR SPACES. ; ; MAGNITUDES OUTSIDE THE ABOVE RANGE ARE REPRESENTED BY A ; SPACE OR MINUS SIGN, A VALUE BETWEEN 1.00000Q AND 9.999999, ; AN EXPONENTIAL SIGN, AND A SIGNED TWO DIGIT POWER OF TEN. ; ; ; THE INP SUBROUTINE CONVERTS CHARACTER STRINGS IN EITHER ; OF THE ABOVE FORMATS, OR A MODIFIED VERSION OF THEM. THE ; LEADING SIGN CHARACTER MAY BE INCLUDED OR OMITTED. UP TO ; 37 DIGITS MAY BE USED TO INDICATE THE VALUE, WITH OR WITHOUT ; AN INCLUDED DECIMAL POINT. IF A POWER-OF-TEN MULTIPLIER ; IS INDICATED IT MAY BE SIGNED OR UNSIGNED AND MAY CONTAIN ; ONE OR TWO DIGITS. AN INPUT CHARACTER STRING IS TERMINATED ; BY THE FIRST CHARACTER WHICH DEPARTS FROM THE SPECIFIED FORMAT. ; ; THE FOLLOWING ARE EXAMPLES OF INPUT AND CORRESPONDING ; OUTPUT CHARACTER STRINGS. ; ; 3. 141593 3.141593 ; -.000000000001Q -1.00000QE-13 ; +1.6E5 160000.0 ; 12345678 1.234568E+08 ; 54321E-10 5.432100E-6Q ; -2718281828 -2.718282E+09 ; ; ; THE INDIVIDUAL SUBROUTINES INCLUDED IN THE FORMAT CONVERSION ; PACKAGE OF THE FLOATING POINT SYSTEM ARE DESCRIBED IN DETAIL ; BELOW. ; ; CHARACTER STRING INPUT SUBROUTINE ; ; THE CHARACTER STRING INPUT SUBROUTINE CONVERTS THE VALUE ; REPRESENTED BY A CHARACTER STRING STORED IN MEMORY TO ; FLOATING POINT FORMAT AND STORES THE RESULT IN THE FLOATING ; POINT ACCUMULATOR. ; ; ENTRY POINT ; INP ; ; ENTRY CONDITIONS ; H REGISTER = MS 6 BITS OF THE ADDRESS OF THE STRING ; L REGISTER = LS 8 BITS OF THE ADDRESS OF THE STRING ; ; EXIT CONDITIONS ; CONTROL BITS SET AS DEFINED FOR THE SYSTEM ; IF OVERFLOW ; LOCATION <OVER> SET NON-ZERO ; IF NO OVERFLOW ; A REGISTER = ACCUM EXP ; B REGISTER = ACCUM SIGN AND 1ST FRACTION ; C REGISTER = ACCUM 2ND FRACTION ; D REGISTER = ACCUM 3RD FRACTION ; ; REGISTERS ALTERED ; ALL ; ; MAXIMUM SUBROUTINE LEVELS USED ; 3 ; ; ; CHARACTER STRING OUTPUT ROUTINE ; ; THE CHARACTER STRING OUTPUT SUBROUTINE CONVERTS THE VALUE ; IN THE FLOATING POINT ACCUMULATOR TO A CHARACTER STRING ; FORMAT CONSISTING OF 13 CHARACTERS AND STORES THE STRING ; IN MEMORY. ; ; ENTRY POINT ; OUT ; ; ENTRY CONDITIONS ; H REGISTER = MS 6 BITS OF THE ADDRESS OF THE STRING ; L REGISTER = LS 8 BITS OF THE ADDRESS OF THE STRING ; ; EXIT CONDITIONS ; CONTROL BITS SET AS DEFINED FOR THE SYSTEM ; A REGISTER = ACCUM EXP ; B REGISTER = ACCUM SIGN AND 1ST FRACTION ; C REGISTER = ACCUM 2ND FRACTION ; D REGISTER = ACCUM 3RD FRACTION ; ; REGISTERS ALTERED ; ALL ; ; MAXIMUM SUBROUTINE LEVELS USED ; 3 ; ; ; FLOAT ROUTINE ; ; THE FLOAT SUBROUTINE CONVERTS THE FIXED POINT FORMAT DATA ; IN THE A,B,C, AND D REGISTERS TO FLOATING POINT FORMAT ; AND STORES THE RESULT IN THE FLOATING POINT ACCUMULATOR. ; ; ENTRY POINT ; FLT ; ; ENTRY CONDITIONS ; A REGISTER = MOST SIG WORD OF THE FIXED POINT VALUE ; B REGISTER = 2ND WORD OF THE FIXED POINT VALUE ; C REGISTER = 3RD WORD OF THE FIXED POINT VALUE ; D REGISTER = LEAST SIG WORD OF THE FIXED POINT VALUE ; E REGISTER = BINARY SCALING FACTOR OF THE FIXED POINT VALUE ; ; EXIT CONDITIONS ; CONTROL BITS SET AS DEFINED FOR THE SYSTEM ; A REGISTER = ACCUM EXP ; B REGISTER = ACCUM SIGN AND 1ST FRACTION ; C REGISTER = ACCUM 2ND FRACTION ; D REGISTER = ACCUM 3RD FRACTION ; ; REGISTERS ALTERED ; ALL ; ; MAXUMUM SUBROUTINE LEVELS USED ; 2 ; ; ; FIX ROUTINE ; ; THE FIX SUBROUTINE CONVERTS THE VALUE IN THE FLOATING ; POINT ACCUMULATOR TO FIXED POINT FORMAT AND RETURNS ; THE RESULT IN THE A,B,C, AND D REGISTERS ; ; ENTRY POINT ; FIX ; ; ENTRY CONDITIONS ; E REGISTER = BINARY SCALING FACTOR OF THE FIXED POINT VALUE ; ; EXIT CONDITIONS ; IF THE VALUE CANNOT BE REPRESENTED AT THE SPECIFIED ; BINARY SCALING FACTOR ; CARRY BIT = 1 ; OTHERWISE ; CARRY BIT = 0 ; ; ZERO BIT = 0 IF THE VALUE IS NON-ZERO ; = 1 IF THE VALUE IS ZERO ; SIGN BIT = 0 IF THE VALUE IS POSITIVE ; = 1 IF THE VALUE IS NEGATIVE ; A REGISTER = MOST SIG WORD OF THE FIXED POINT VALUE ; B REGISTER = 2ND WORD ; C REGISTER = 3RD WORD ; D REGISTER = LEAST SIG WORD OF THE FIXED POINT VALUE ; ; REGISTERS ALTERED ; ALL ; ; MAXIMUM SUBROUTINE LEVELS USED ; 1 ; ORG 3000Q SCR EQU 5400Q SCRB EQU 13Q ARITH EQU 1400Q ;BASE ADDRESS OF ARITHMETIC PKG SPACE EQU 360Q PLUS EQU 373Q MINUS EQU 375Q POINT EQU 376Q EXPO EQU 25Q ; ; 8008 BINARY FLOATING POINT SYSTEM ; FORMAT CONVERSION PACKAGE ; PROGRAMMER: CAL OHME ; DATE: 26 DECEMBER 1973 ; ARITH IS THE BEGINNING ADDRESS OF THE ; ARITHMETIC AND UTILITY PACKAGE OF THE FLOATING POINT SYSTEM ; SCR IS THE BEGINNING ADDRESS OF THE RAM USED AS SCRATCHPAD ; OVER EQU 56Q ;OVERFLOW FLAG ACCE EQU 60Q ;ACCUM EXP ACCS EQU ACCE+1 ;ACCUM SIGN ACC1 EQU ACCS+1 ;ACCUM 1ST FRACTION ACC2 EQU ACC1+1 ;ACCUM 2ND FRACTION ACC3 EQU ACC2+1 ;ACCUM 3RD FRACTION SF EQU ACC3+1 ;SUBTRACTION FLAG ADRL EQU SF+1 ;CHARACTER STRING WORD ADRH EQU ADRL+1 ;CHARACTER STRING BANK TMP1 EQU ADRH+1 ;TEMPORARY STORAGE TMP2 EQU TMP1+1 TMP3 EQU TMP2+1 VALE EQU TMP3+1 ;VALUE EXPONENT VAL1 EQU VALE+1 ;VALUE 1ST FRACTION VAL2 EQU VAL1+1 ;VALUE 2ND FRACTION VAL3 EQU VAL2+1 ;VALUE 3RD FRACTION TMP4 EQU VAL3+1 ;TEMPORARY STORAGE ; ; ADDRESSES IN THE ARITHMETIC AND UTILITY PACKAGE ; REFERENCED BY THE FORMAT CONVERSION PACKAGE . ; STR EQU ARITH+76Q ZRO EQU ARITH+106Q ABS EQU ARITH+120Q TST EQU ARITH+131Q LOD EQU ARITH+156Q MUL EQU ARITH+214Q DIV EQU ARITH+264Q ADD EQU ARITH+327Q ADD10 EQU ARITH+553Q LSH EQU ARITH+674Q RSH EQU ARITH+711Q COMP EQU ARITH+757Q ; ; SUBROUTINE TO CONVERT FROM FIXED POINT TO FLOATING POINT FORMAT ; FLT: MOV L,E ;INPUT EXP MOV E,D ;4TH INPUT FRACTION MOV D,C ;3RD INPUT FRACTION MOV C,B ;2ND INPUT FRACTION MOV B,A ;1ST INPUT FRACTION MOV A,L ;INPUT EXP XRI 200Q ;APPLY EXPONENT BIAS MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,ACCE ;ADDRESS ACCUM EXP MOV M,A ;STORE ACCUM EXP INR L ;ADDRESS ACCUM SIGN MVI M,200Q ;SET ACCUM SIGN POSITIVE INR L ;ADDRESS ACCUM 1ST FRACTION MOV A,B ;1ST INPUT FRACTION ANA A ;SET SIGN BIT RAL ;INPUT SIGN TO CARRY JMP ADD10 ;COMPLETE CONVERSION ; ; SUBROUTINE TO CONVERT FROM FLOATING POINT TO FIXED POINT FORMAT ; FIX: MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,ACCE ;ADDRESS ACCUM EXP MOV A,M ANA A ;SET CONTROL BITS JZ FIX1 ;IF ACCUM IS ZERO MOV A,E ;INPUT EXP ADI 177Q ;ADD BIAS-1 SUB M ;SHIFT COUNT -1 RC ;RETURN IF ACCUM TOO LARGE CPI 31 ;COMPARE TO LARGE SHIFT JNC FIX1 ;IF ACCUM TO SMALL ADI 1 ;SHIFT COUNT MVI L,ACC1 ;ADDRESS ACCUM 1ST FRACTION MOV B,M INR L ;ADDRESS ACCUM 2ND FRACTION MOV C,M INR L ;ADDRESS ACCUM 3RD FRACTION MOV D,M CALL RSH ;POSITION THE FRACTION MVI L,ACCS ;ADDRESS ACCUM SIGN MOV A,M ANA A ;SET CONTROL BITS CP COMP ;COMPLEMENT FRACTION IF NEGATIVE MVI A,1 ;NON-ZERO ORA B ;SET CONTROL BITS FOR EXIT MOV A,B ;1ST RESULT MOV B,C ;2ND RESULT MOV C,D ;3RD RESULT MOV D,E ;4TH RESULT RET FIX1: XRA A ;SET A REG TO ZERO MOV B,A MOV C,A MOV D,A RET DB 0 ;CHECKSUM WORD ; ; INP SUBROUTINE ENTRY POINT ; INITIALIZE TEMPORARY STORAGE ; INP: MOV E,M ;FIRST CHAR OF STRING CALL SVAD ;SET CHAR ADDR, PNT FLAG, EXP INR L ;ADDRESS VALUE SIGN MVI M,200Q ;SET VALUE SIGN POSITIVE MVI L,ACCE ;ADDRESS ACCUM EXP MOV M,D ;SET ACCUM TO ZERO MOV A,E ;1ST CHAR CPI SPACE ;COMPARE TO SPACE JZ INP1 ;IF SPACE CHAR CPI PLUS ;COMPARE TO PLUS JZ INP1 ;IF PLUS SIGN CPI MINUS ;COMPARE TO MINUS JNZ INP2 ;IF NOT MINUS SIGN MVI L,TMP3 ;ADDRESS VALUE SIGN MOV M,D ;SET VALUE SIGN NEGATIVE ; ; ANALYZE NEXT CHARACTER IN STRING ; INP1: CALL CHAD ;CALL CHAR ADDRESS SUBROUTINE MOV A,M ;NEXT CHAR MVI H,SCRB ;ADDRESS SCRATCH BANK INP2: MVI B,0 ;DIGIT 2ND WORD OR DEC EXP CPI POINT ;COMPARE TO DECIMAL POINT JZ INP3 ;IF DECIMAL POINT CPI EXPO ;COMPARE TO EXPONENT SIGN JZ INP4 ;IF EXPONENT SIGN CPI 10 ;SET CARRY IF CHAR IS A DIGIT JNC INP8 ;IF CHAR IS NOT A DIGIT MVI L,TMP4 ;ADDRESS CURRENT DIGIT MOV M,A ;SAVE CURRENT DIGIT LXI H,FTEN ;ADDRESS FLOATING TEN CALL MUL ;MULTIPLY BY TEN MVI L,VALE ;ADDRESS VALUE CALL STR ;STORE OLD VALUE TIMES TEN INR L ;ADDRESS CURRENT DIGIT MOV A,M MVI B,0 ;CLEAR 2ND WORD OF DIGIT MOV C,B ;CLEAR 3RD WORD MOV D,B ;CLEAR 4TH WORD MVI E,8 ;INDICATE DIGIT IS IN REG A CALL FLT ;CONVERT DIGIT TO FLOATING POINT MVI L,VALE ;ADDRESS VALUE CALL ADD ;ADD OLD VALUE TIMES TEN MVI L,TMP2 ;ADDRESS DECIMAL POINT FLAG MOV A,M ANA A ;SET CONTROL BITS JZ INP1 ;IF NO DECIMAL POINT ENCOUNTERED DCR L ;ADDRESS INPUT EXP MOV B,M DCR B ;DECREMENT INPUT EXP MOV M,B ;UPDATE INPUT EXP JMP INP1 ;GET NEXT CHAR INP3: MVI L,TMP2 ;ADDRESS DECIMAL POINT FLAG XRA M ;ZERO IF FLAG SET MOV M,A ;SET DEC POINT FLAG JNZ INP1 ;IF FLAG NOT ALREADY SET JMP INP8 ;IF 2ND DECIMAL POINT ; ; PROCESS DECIMAL EXPONENT ; INP4: CALL CHAD ;CALL CHAR ADDR SUB MOV A,M ;NEXT CHAR OF STRING MOV B,A ;CURRENT CHAR SUI MINUS ;COMPARE TO MINUS CHAR MOV E,A ;CHAR - <MINUS SIGN> JZ INP5 ;IF MINUS SIGN ADI MINUS-PLUS ;COMPARE TO PLUS SIGN MOV A,B ;CURRENT CHAR JNZ INP6 ;IF NOT PLUS SIGN INP5: INR L ;ADDRESS NEXT CHAR MOV A,M ;NEXT CHAR OF STRING INP6: MVI B,0 ;POSSIBLE DECIMAL EXPONENT CPI 10 ;SET CARRY IF CHAR IS A DIGIT JNC INP8 ;IF CHAR IS NOT A DIGIT MOV B,A ;DEC EXP EQUAL DIGIT INR L ;ADDRESS NEXT CHAR MOV A,M CPI 10 ;SET CARRY IF A DIGIT JNC INP7 ;IF CHAR IS NOT A DIGIT ; ; FORM COMPLETE DECIMAL EXPONENT ; MOV C,A ;LS DIGIT OF DEC EXP MOV A,B ;MS DIGIT OF DEC EXP ADD A ;2 * MS DIGIT ADD A ;4 * MS DIGIT ADD B ;5 * MS DIGIT ADD A ;10 * MS DIGIT ADD C ;10 * MS + LS DIGIT MOV B,A ;DECIMAL EXP INP7: MOV A,E ;SIGN OF DEC EXP ANA A ;SET CONTROL BITS JNZ INP8 ;IF SIGN PLUS SUB B ;COMPLEMENT DEC EXP MOV B,A ;DEC EXP INP8: MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,TMP3 ;ADDRESS INPUT SIGN MOV C,M MVI L,ACCS ;ADDRESS ACCUM SIGN MOV M,C ;STORE ACCUM SIGN MOV A,B ;DEC EXP ; ; CONVERT DECIMAL EXPONENT TO BINARY ; INP9: MVI L,TMP1 ;ADDRESS DEC EXP ADD M ;ADJUST DEC EXP JZ TST ;IF DEC EXP IS ZERO MOV M,A ;CURRENT DEC EXP LXI H,FTEN ;ADDRESS FLOATING POINT TEN JP INP10 ;IF MULTIPLY REQUIRED CALL DIV ;DIVIDE BY 10 MVI A,1 ;TO INCREMENT DEC EXP JMP INP9 ;TEST FOR COMPLETION INP10: CALL MUL ;MULTIPLY BY 10 RC ;RETURN IF OVERFLOW MVI A,-1 ;DECREMENT DEC EXP JMP INP9 ;TO TEST FOR COMPLETION ; ; OUT SUBROUTINE ENTRY POINT ; SAVE CHARACTER ADDRESS AND ACCUMULATOR. ; OUT: DCR L ;DECREMENT CHAR ADDRESS CALL SVAD ;SET CHAR ADDR, DIG CNT, DEC EXP CALL TST ;LOAD ACCUM TO REGISTERS MVI L,VALE ;ADDRESS ACCUM SAVE AREA CALL STR ; ; OUTPUT SIGN CHAR ; CALL CHAD ;CALL CHAR ADDR SUBROUTINE MVI M,SPACE ;STORE SPACE CHAR ANA A ;SET CONTROL BITS JZ OUT3 ;IF ACCUM IS ZERO MOV E,A ;ACCUM EXP MOV A,B ;ACCUM SIGN AND 1ST FRACTION ANA A ;SET CONTROL BITS MOV A,E ;ACCUM EXP JP OUT1 ;IF ACCUM IS POSITIVE MVI M,MINUS ;CHANGE SIGN TO MINUS ; ; SCALE ACCUM TO .1 - 1. RANGE ; OUT1: CPI 176Q ;COMPARE TO SMALL EXPONENT OUT2: LXI H,FTEN ;ADDRESS OF FLOATING TEN JC OUT4 ;IF EXPONENT TOO SMALL CPI 201Q ;COMPARE TO LARGE EXP JC OUT5 ;IF EXP SMALL ENOUGH CALL DIV ;DIVIDE BY TEN OUT3: MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,TMP2 ;ADDRESS DECIMAL EXP MOV E,M INR E ;INCREMENT DEC EXP MOV M,E ;STORE DECIMAL EXP JMP OUT2 ;TEST FOR SCALING COMPLETE OUT4: CALL MUL ;MULTIPLY BY TEN MVI L,TMP2 ;ADDRESS DECIMAL EXP MOV E,M DCR E ;DECREMENT DEC EXP MOV M,E JMP OUT1 ;TEST FOR SCALING COMPLETE ; ; ROUND THE VALUE BY ADDING .0000005Q ; OUT5: CALL ABS ;SET ACCUM POSITIVE LXI H,RND0 ;ADDRESS ROUNDER CALL ADD ;ADD THE ROUNDER CPI 201Q ;CHECK FOR OVERFLOW JNC OUT2 ;IF EXP TOO LARGE ; ; SET DIGIT COUNTS ; MVI L,TMP2 ;ADDRESS DEC EXP MOV A,M MOV E,A ;DIGITS BEFORE DECIMAL POINT CPI 8 ;COMPARE TO LARGE EXP JC OUT6 ;IF EXPONENT IN RANGE MVI E,1 ;DIGITS BEFORE DECIMAL POINT OUT6: SUB E ;ADJUST DEC EXP MOV M,A ;DEC EXP MVI A,7 ;TOTAL NUMBER OF DIGITS SUB E ;DIGITS AFTER DECIMAL POINT INR L ;ADDRESS 2ND DIGIT CNT MOV M,A ;DIGITS AFTER DEC POINT DCR E ;DECREMENT DIGIT COUNT MOV A,E ;DIGITS BEFORE DEC POINT ; ; OUTPUT SIGNIFICANT DIGITS ; OUT7: MVI L,TMP1 ;ADDRESS DIGIT COUNT ADD M ;ADJUST DIGIT COUNT MOV M,A ;NEW DIGIT COUNT JM OUT8 ;IF COUNT RUN OUT LXI H,FTEN ;ADDRESS FLOATING TEN CALL MUL ;MULTIPLY BY TEN MVI E,8 ;TO PLACE DIGIT IN REGISTER A CALL FIX ;CONVERT TO FIXED POINT FORMAT CALL CHAD ;CALL CHAR ADDRESS SUBROUTINE MOV M,A ;SEND OUT DECIMAL DIGIT XRA A ;CLEAR CURRENT DIGIT MVI E,8 ;BINARY SCALING FACTOR CALL FLT ;RESTORE VALUE MINUS DIGIT MVI A,-1 ;TO ADJUST DIGIT COUNT JMP OUT7 ;LOOP FOR NEXT DIGIT OUT8: MVI L,TMP3 ;ADDRESS 2ND DIGIT CNT MOV A,M ;DIGITS AFTER DECIMAL POINT MVI M,-1 ;SET 2ND COUNT NEGATIVE ANA A ;SET CONTROL BITS JM OUT9 ;IF 2ND COUNT RAN OUT CALL CHAD ;CALL CHAR ADDR SUBROUTINE MVI M,POINT ;STORE DECIMAL POINT MVI H,SCRB ;ADDRESS SCRATCH BANK JMP OUT7 ;LOOP FOR NEXT DIGIT OUT9: DCR L ;ADDRESS DECIMAL EXP ANA M ;DEC EXP JZ OUT13 ;IF DEC EXP IS ZERO ; ; SEND OUT DECIMAL EXPONENT ; MVI B,PLUS ;PLUS CHARACTER JP OUT10 ;IF EXP IS POSITIVE MVI B,MINUS ;CHANGE SIGN TO MINUS MOV C,A ;NEGATIVE EXP XRA A ;CLEAR A REG SUB C ;COMPLEMENT EXP OUT10: MVI C,-1 ;EMBRYO TENS DIGIT OUT11: MOV D,A ;UNITS DIGIT INR C ;INCREMENT TENS DIGIT SUI 10 ;REDUCE REMAINDER JNC OUT11 ;IF MORE TENS MVI A,EXPO ;EXPONENT SIGN OUT12: CALL CHAD ;CHAR ADR SUBROUTINE CALL STR ;STORE LAST 4 CHARACTERS MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,VALE ;ADDRESS ACCUM SAVE AREA JMP LOD ;RESTORE ACCUM AND EXIT ; ; SEND OUT 4 SPACES IF EXPONENT IS ZERO ; OUT13: MVI A,SPACE ;SPACE CHARACTER MOV B,A MOV C,A MOV D,A JMP OUT12 ;STORE CHARACTERS ; ; SUBROUTINE TO SAVE CHARACTER STRING ADDRESS ; SVAD: MOV A,L ;CHARACTER STRING WORD MOV B,H ;CHARACTER STRING BANK MVI C,0 ;INPUT EXP OR DIGIT COUNT MOV D,C ;DEC PNT FLAG OR DEC EXP MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,ADRL ;ADDRESS CHAR STRING WORD CALL STR ;STORE A,B,C,AND D RET ; ; SUBROUTINE TO OBTAIN NEXT CHARACTER ADDRESS ; CHAD: MVI H,SCRB ;ADDRESS SCRATCH BANK MVI L,ADRL ;ADDRESS CHAR STRING WORD MOV E,M ;CHAR STRING WORD INR E ;ADDRESS NEXT CHAR MOV M,E ;UPDATE CHAR STRING WORD INR L ;ADDRESS CHAR STRING BANK MOV H,M ;CHAR STRING BANK MOV L,E ;CHAR STRING WORD RET FTEN: DB 204Q,40Q,0,0 ;FLOATING TEN RND0: DB 150Q,126Q,277Q,225Q ;.0000005Q DB 0 ;CHECKSUM WORD END