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2
Help me please:
Through a comma introduces an array of two-digit values, by pressing "=" displays the pairwise sum of array elements (first+second,second+third ...)
i8080 (emulator z80 and linker L80)
I have a program for addition of three two-digit numbers (can be this program as that to change for my case):
;exp:
; 12+10+22=44
; 99+99+99=297
jmp start
n1: db 00h, 00h
n2: db 00h, 00h
n3: db 00h, 00h
plus1: db 00h
plus2: db 00h
equals: db 00h
;onemoredigit: db 00h
;============================================
; MAIN PROGRAM
;============================================
start:
;read 3 numbers
call read ; N1
call check_dec ; then check
pop b
jnc error
sui '0' ; if not error then convert ascii to hex
sta n1+1 ; save
call read
call check_dec
jnc error
sui '0' ; if not error then convert ascii to hex
sta n1
call read ;+
sui '+' ; ascii '+'
jnz error
call read ;N2
call check_dec
jnc error
sui '0' ; if not error then convert ascii to hex
sta n2+1
call read
call check_dec
jnc error
sui '0' ; if not error then convert ascii to hex
sta n2
call read
sui '+'
jnz error
call read ;N3
call check_dec
jnc error
sui '0' ; if not error then convert ascii to hex
sta n3+1
call read
call check_dec
jnc error
sui '0' ; if not error then convert ascii to hex
sta n3
call read ;=
sui '='
jnz error
;CALCULATE SUM OF 3 NUMBERS save to de and n1, n1+1
start_sum:
lda n1
mov b, a
lda n2
add b
mov b, a
lda n3
add b
call todecimal
mov a, e
adi '0'
sta n1
lda n1+1
mov b, a
lda n2+1
add b
mov b, a
lda n3+1
add b
add d
call todecimal
mov a, e
adi '0'
sta n1+1
mvi a, 00h
add d
adi '0'
;sta onemoredigit
;result
mvi b, '0'
cmp b
jz skipzeroprint
call print
skipzeroprint:
lda n1+1
call print
lda n1
call print
jmp exit
;============================================
; CONVERT BYTE TO DECIMAL DIGIT AND SUM OF OVERFLOWS
;============================================
todecimal:
; input byte a
; uses d, e, a
; return d:e, e<9h
mvi d, 00h
loop:
mov e, a
mvi a, 9h ; esli bol'she 9 to ...
cmp e
mov a, e
jnc nooverflow
sui 0Ah ; +6h -10h = Ah
inr d
jmp loop
nooverflow:
ret
;============================================
; READ ONE BYTE FROM SCREEN
;============================================
read:
; return one byte in a
push b
push h
mvi c, 01h
call 0005h
pop h
pop b
ret
;============================================
; PRINT ONE BYTE TO SCREEN
;============================================
print:
; data is A
push b
push d
push h
push psw
mov e, a
mvi c, 02h
call 0005h
pop psw
pop h
pop d
pop b
ret
;============================================
; CHECK IF BYTE IS A DEC DIGIT
;============================================
check_dec:
; byte is in a
; uses a, b
; return cf=hex ncf=not a digit
digit:
mvi b, 30h
cmp b
jc nodig
mvi b, 40h
cmp b
jnc nodig
stc ; set cf cf=1
ret
nodig:
stc ; set cf
cmc ; invert cf cf=0
ret
;============================================
; END
;============================================
error:
mvi a, 3Fh ; ascii '?'
call print
exit:
;mvi a, 0Dh ;print something on exit
;call print
ret
END
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