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agoodkind/twosum.asm

Created October 17, 2019 19:16
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twosum.asm
.Orig x3000
INIT_CODE
LEA R6, #-1
ADD R5, R6, #0
ADD R6, R6, R6
ADD R6, R6, R6
ADD R6, R6, R5
ADD R6, R6, #-1
ADD R5, R5, R5
ADD R5, R6, #0
LD R4, GLOBAL_DATA_POINTER
LD R7, GLOBAL_MAIN_POINTER
jsrr R7
HALT
GLOBAL_DATA_POINTER .FILL GLOBAL_DATA_START
GLOBAL_MAIN_POINTER .FILL main
;;;;;;;;;;;;;;;;;;;;;;;;;;;;main;;;;;;;;;;;;;;;;;;;;;;;;;;;;
main
ADD R6, R6, #-2
STR R7, R6, #0
ADD R6, R6, #-1
STR R5, R6, #0
ADD R5, R6, #-1
ADD R6, R6, #-2
ADD R7, R4, #15
ADD R7, R7, #15
ADD R7, R7, #15
ADD R7, R7, #15
ADD R7, R7, #15
ADD R7, R7, #5
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #2
LDR R0, R0, #0
jsrr R0
ADD R7, R4, #15
ADD R7, R7, #15
ADD R7, R7, #15
ADD R7, R7, #5
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #2
LDR R0, R0, #0
jsrr R0
ADD R7, R5, #0
ADD R6, R6, #-1
STR R7, R6, #0
ADD R7, R4, #15
ADD R7, R7, #15
ADD R7, R7, #15
ADD R7, R7, #2
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #1
LDR R0, R0, #0
jsrr R0
ADD R7, R4, #15
ADD R7, R7, #2
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #2
LDR R0, R0, #0
jsrr R0
ADD R7, R5, #-1
ADD R6, R6, #-1
STR R7, R6, #0
ADD R7, R4, #14
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #1
LDR R0, R0, #0
jsrr R0
ldr R7, R5, #0
ldr R3, R5, #-1
add R7, R7, R3
ADD R6, R6, #-1
STR R7, R6, #0
ADD R7, R4, #4
ADD R6, R6, #-1
STR R7, R6, #0
ADD R0, R4, #2
LDR R0, R0, #0
jsrr R0
ADD R7, R4, #3
ldr R7, R7, #0
lc3_L1_twosum
STR R7, R5, #3
ADD R6, R5, #1
LDR R5, R6, #0
ADD R6, R6, #1
LDR R7, R6, #0
ADD R6, R6, #1
RET
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; void scanf(const char *format, ...)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
SCANF_PERCENT .FILL -37
SCANF_C .FILL -99
SCANF_D .FILL -100
SCANF_S .FILL -115
SCANF_0 .FILL -48
SCANF_9 .FILL -57
SCANF_MINUS .FILL -45
SCANF_BUF .BLKW 6
lc3_scanf
ADD R6, R6, #-2
STR R7, R6, #0
ADD R6, R6, #-1 ;save R5 = bp
STR R5, R6, #0
ADD R5, R6, #-1
ADD R6, R6, #-1 ;save R4 = gp
STR R4, R6, #0
ADD R5, R5, #4 ;cheating with the bp (no longer bp)
LDR R4, R5, #0 ;got addr of format string
SCANF_LOOP ;outer loop, R0=tmp register for use with GETC
;R2 holds either cur letter of format string or
;current addr to store a char, dec, or string
LDR R2, R4, #0
ADD R2, R2, #0 ;End of format string? (0x0000)
BRz SCANF_DONE
LD R1, SCANF_PERCENT
ADD R0, R2, #0
ADD R0, R0, R1
BRnp SCANF_MATCHCHAR ;% not found
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;% found!
ADD R4, R4, #1 ;R4 points to next char of format string
LDR R2, R4, #0
LD R1, SCANF_C
ADD R0, R2, #0 ;next char = c?
ADD R0, R0, R1
BRnp SCANF_CHECKD
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%c found
ADD R5, R5, #1
LDR R2, R5, #0 ;R2 has addr for char to be read into
GETC
OUT
STR R0, R2, #0
ADD R4, R4, #1
BRnzp SCANF_LOOP
SCANF_CHECKD
;is it %d?
LD R1, SCANF_D
ADD R0, R2, #0
ADD R0, R0, R1
BRnp SCANF_STR
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%d found
;consider using vars to store reg
;registers 0,1,2,3,7 available as tmp regs
ADD R6, R6, #-1 ;saving current ptr into format string
STR R4, R6, #0
;ADD R6, R6, #-7 ;making 7byte buffer for ascbin
;ADD R4, R6, #0 ;ptr into that buffer
LEA R4, SCANF_BUF
LD R2, SCANF_0
LD R1, SCANF_9
SCANF_SCANNUM
GETC
OUT
STR R0, R4, #0 ;Reading and storing typed char
ADD R0, R2, R0
BRZP SCANF_CHECKEDLOWER
LDR R0, R4, #0
LD R7, SCANF_MINUS
ADD R0, R0, R7
BRz SCANF_CHECKEDLOWER
LEA R0, SCANF_BUF
NOT R0, R0
ADD R0, R0, #1
ADD R0, R4, R0
BRz SCANF_SCANNUM ;buffer is empty and wrong char, go to error?
ADD R4, R4, #-1 ;fixme: need to save this char
BRnzp SCANF_NUMDONE
SCANF_CHECKEDLOWER
LDR R0, R4, #0
ADD R0, R1, R0
BRNZ SCANF_CHECKEDUPPER
LEA R0, SCANF_BUF
NOT R0, R0
ADD R0, R0, #1
ADD R0, R4, R0
BRz SCANF_SCANNUM ;buffer is empty and wrong char, go to error?
ADD R4, R4, #-1 ;fixme: need to save this char
BRnzp SCANF_NUMDONE
SCANF_CHECKEDUPPER
LEA R0, SCANF_BUF
ADD R0, R0, #5
NOT R0, R0
ADD R0, R0, #1
ADD R0, R4, R0
BRz SCANF_NUMDONE ;buffer is full
ADD R4, R4, #1
BRnzp SCANF_SCANNUM
SCANF_NUMDONE
;R4 points to last char entered in (ones digit)
;ADD R7, R6, #0 ;R7 points to the highest order digit
LEA R7, SCANF_BUF
LD R0, SCANF_MINUS
LD R1, SCANF_BUF
ADD R0, R0, R1
BRnp SCANF_NOTMINUS
ADD R7, R7, #1 ;fixme check for - -
SCANF_NOTMINUS
;STR R2, R6, #-1 ;psuedo stored -'0' on stack
AND R2, R2, #0 ;R2 acts as the acumulator
SCANF_CALC
LDR R0, R7, #0
;LDR R1, R6, #-1
LD R1, SCANF_0
ADD R0, R0, R1
ADD R2, R2, R0
NOT R1, R7
ADD R1, R1, #1
ADD R1, R4, R1
BRz SCANF_CALCDONE
;R2 = 10*R2
ADD R0, R2, #0
AND R1, R1, #0
ADD R1, R1, #9 ;R1 = counter
SCANF_MULLOOP
ADD R2, R2, R0
ADD R1, R1, #-1
BRnp SCANF_MULLOOP
ADD R7, R7, #1
BRnzp SCANF_CALC
SCANF_CALCDONE
LD R0, SCANF_MINUS
LD R1, SCANF_BUF
ADD R0, R0, R1
BRnp SCANF_NOTNEG
NOT R2, R2
ADD R2, R2, #1
SCANF_NOTNEG
ADD R5, R5, #1
LDR R0, R5, #0
STR R2, R0, #0 ;store decimal number into address
;ADD R6, R6, #7
LDR R4, R6, #0
ADD R6, R6, #1 ;restoring current ptr into format string
ADD R4, R4, #1 ;point to next element of format string
BRnzp SCANF_LOOP
SCANF_STR
LD R1, SCANF_S
ADD R0, R2, #0
ADD R0, R0, R1
BRnp SCANF_ERROR
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%s found
ADD R6, R6, #-1 ;saving current ptr into format string
STR R4, R6, #0
ADD R5, R5, #1 ;getting starting addr of space for string to be read in
LDR R4, R5, #0
SCANSTRLOOP
GETC
OUT
STR R0, R4, #0 ;Reading and storing typed char
ADD R4, R4, #1
ADD R0, R0, #-10 ;End of string? Looking for CR (0x000A)
BRnp SCANSTRLOOP
SCANSTRDONE
AND R0, R0, #0 ;null terminate string
STR R0, R4, #-1
LDR R4, R6, #0 ;restore r4
ADD R6, R6, #1
ADD R4, R4, #1
BRnzp SCANF_LOOP
SCANF_MATCHCHAR
ADD R4, R4, #1
GETC
OUT
NOT R0, R0
ADD R0, R0, #1
ADD R0, R0, R2
BRz SCANF_LOOP
SCANF_ERROR
SCANF_DONE
LDR R4, R6, #0 ;restore R4
ADD R6, R6, #1
LDR R5, R6, #0 ;restore bp
ADD R6, R6, #1
LDR R7, R6, #0 ;restore ret addr
ADD R6, R6, #1
RET
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; void printf(const char *format, ...)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
PRINTF_PERCENT .FILL -37
PRINTF_C .FILL -99
PRINTF_D .FILL -100
PRINTF_S .FILL -115
PRINTF_B .FILL -98
PRINTF_O .FILL -111
PRINTF_X .FILL -120
PRINTF_ASCII .FILL 48 ;postive ascii value of '0'
.FILL 49
.FILL 50
.FILL 51
.FILL 52
.FILL 53
.FILL 54
.FILL 55
.FILL 56
.FILL 57
.FILL 65 ;A
.FILL 66
.FILL 67
.FILL 68
.FILL 69
.FILL 70
PRINTF_MINUS .FILL 45
PRINTF_BUF .BLKW 18
lc3_printf
ADD R6, R6, #-2
STR R7, R6, #0 ;return address
ADD R6, R6, #-1
STR R5, R6, #0
ADD R5, R6, #-1
ADD R6, R6, #-1
STR R4, R6, #0
ADD R5, R5, #4 ;cheating with the bp (no longer bp)
LDR R4, R5, #0 ;got addr of format string
PRINTF_LOOP ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
LDR R0, R4, #0
ADD R0, R0, #0 ;End of string? (0x0000)
BRz PRINTF_DONE
ADD R2, R0, #0
LD R1, PRINTF_PERCENT
ADD R2, R2, R1
BRnp PRINTF_CHAR
ADD R4, R4, #1
LDR R0, R4, #0
;is it %c?
ADD R2, R0, #0
LD R3, PRINTF_C
ADD R2, R2, R3
BRnp PRINTF_CHECKSTR
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%c
ADD R5, R5, #1
LDR R0, R5, #0
PRINTF_CHAR
OUT
ADD R4, R4, #1
BRnzp PRINTF_LOOP
PRINTF_CHECKSTR
;is it %s?
ADD R2, R0, #0
LD R7, PRINTF_S
ADD R2, R2, R7
BRnp PRINTF_CHECKDEC
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%s
ADD R5, R5, #1
LDR R0, R5, #0
PUTS
ADD R4, R4, #1
BRnzp PRINTF_LOOP
PRINTF_CHECKDEC
;is it %d?
ADD R2, R0, #0
LD R7, PRINTF_D
ADD R2, R2, R7
;BRnp PRINTF_ERROR
BRnp PRINTF_CHECKHEX
AND R2, R2, #0
ADD R2, R2, #-10 ;going to divide by 10 by using sub loop
BRnzp PRINTF_NUM
PRINTF_CHECKHEX
ADD R2, R0, #0
LD R7, PRINTF_X
ADD R2, R2, R7
BRnp PRINTF_CHECKOCT
AND R2, R2, #0
ADD R2, R2, #-16 ;going to divide by 10 by using sub loop
BRnzp PRINTF_NUM
PRINTF_CHECKOCT
ADD R2, R0, #0
LD R7, PRINTF_O
ADD R2, R2, R7
BRnp PRINTF_CHECKBIN
AND R2, R2, #0
ADD R2, R2, #-8 ;going to divide by 10 by using sub loop
BRnzp PRINTF_NUM
PRINTF_CHECKBIN
ADD R2, R0, #0
LD R7, PRINTF_B
ADD R2, R2, R7
BRnp PRINTF_ERROR
AND R2, R2, #0
ADD R2, R2, #-2 ;going to divide by 10 by using sub loop
;BRnzp PRINTF_NUM
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;%d
PRINTF_NUM
LEA R7, PRINTF_BUF
ADD R7, R7, #15
ADD R7, R7, #1
;AND R2, R2, #0
;ADD R2, R2, #-10 ;going to divide by 10 by using sub loop
ADD R5, R5, #1 ;acquire the binary number
LDR R0, R5, #0
ADD R0, R0, #0
BRzp PRINTF_DECPOS
NOT R0, R0 ;make num positive for sub loop
ADD R0, R0, #1
PRINTF_DECPOS
AND R3, R3, #0
ADD R3, R3, #-1
PRINTF_DIVLOOP
ADD R3, R3, #1 ;num/10
ADD R0, R0, R2 ;R0 = num % 10 - 10
BRzp PRINTF_DIVLOOP
ADD R3, R3, #0
BRz PRINTF_LASTDIGIT
;LD R1, PRINTF_ASCII
;ADD R1, R1, R0
;NOT R2, R2
;ADD R1, R1, R2
;ADD R1, R1, #1
;NOT R2, R2
;;;;;ADD R1, R1, #10
;STR R1, R7, #0
;ADD R7, R7, #-1 ;stored ascii value of one digit
LEA R1, PRINTF_ASCII
ADD R1, R1, R0
NOT R2, R2
ADD R1, R1, R2
ADD R1, R1, #1
NOT R2, R2
LDR R1, R1, #0
STR R1, R7, #0
ADD R7, R7, #-1 ;stored ascii value of one digit
ADD R0, R3, #0 ;num/10
BRnzp PRINTF_DECPOS
PRINTF_LASTDIGIT
;LD R1, PRINTF_ASCII
;ADD R1, R1, R0
;ADD R1, R1, #10
;STR R1, R7, #0
LEA R1, PRINTF_ASCII
ADD R1, R1, R0
NOT R2, R2
ADD R1, R1, R2
ADD R1, R1, #1
NOT R2, R2
LDR R1, R1, #0
STR R1, R7, #0 ;stored ascii value of highest order digit
LDR R0, R5, #0
ADD R0, R0, #0
BRzp PRINTF_DECSTRING
LD R0, PRINTF_MINUS ;num was negative
ADD R7, R7, #-1
STR R0, R7, #0 ;stored ascii value negative sign
PRINTF_DECSTRING ;print the calculated string
ADD R0, R7, #0
PUTS
ADD R4, R4, #1
BRnzp PRINTF_LOOP
PRINTF_ERROR
PRINTF_DONE
LDR R4, R6, #0 ;restore R4
ADD R6, R6, #1
LDR R5, R6, #0 ;restore bp
ADD R6, R6, #1
LDR R7, R6, #0 ;restore ret addr
ADD R6, R6, #1
RET
GLOBAL_DATA_START
L1_twosum .FILL lc3_L1_twosum
scanf .FILL lc3_scanf
printf .FILL lc3_printf
L8_twosum .FILL #0
L7_twosum .STRINGZ "Sum is %d"
L6_twosum .STRINGZ "%d"
L5_twosum .STRINGZ "Enter a 2-digit number <##>: "
L4_twosum .STRINGZ "%d"
L3_twosum .STRINGZ "Enter a 2-digit number <##>: "
L2_twosum .STRINGZ "This program will add two 2-digit numbers.\nUse 0 as a placeholder for a single digit number (07 for 7 etc)\n"
.END
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