我正在编写一个程序来接受以下字符之一的用户输入，0-9、+、-、*、/ 和 ^。它一次只需要两个操作数，并且以逆波兰符号表示，例如 5 6 + 或 2 8 /。除了用户输入部分，我已经弄清楚了一切。我知道要使用 GETC 和 OUT，但我不明白这两个函数是如何工作的，因此在程序开始时很难实现它们。这就是我所拥有的。它目前编译没有错误，但似乎无法正常工作。
;介绍段落
; 我将从定义我的寄存器用途开始。R0 保存用户输入的最后一个字符。R1、R2、R3 和 R4；都只是临时寄存器，它们保存仅对即时任务重要的值。R6 是我的堆栈指针。
; R5 是我用来从堆栈中取出信息的工具。我首先将所有寄存器初始化为零。从那里我拿
; 用户输入的最后一个字符，并通过条件过滤以找出它是什么字符以及什么子程序
；发送到。如果是数字 0-9，则直接压入堆栈。如果它是无效字符，则跳转到
; 输出消息的 INVALID_CHARACTER 循环然后终止程序。如果它是一个操作符，它会被发送到 DECODE 那里
; 它的十六进制值反转，然后通过几个条件发送以找出它是哪个运算符以及哪个循环
；发送到。如果可能会混淆每个寄存器的含义，则在运算符循环上方说明了寄存器的使用
；被用于。最后，程序将在看到换行符时终止。在这里，我将 xA 设置为新行
；特点。
.ORIG x3000
;initializes all registers to zero
AND R0, R0, #0
AND R1, R1, #0
AND R2, R2, #0
AND R3, R3, #0
AND R4, R4, #0
AND R5, R5, #0
AND R6, R6, #0
AND R7, R7, #0
;this block will ask for user input then display it to the monitor
NEXTCHARACTER GETC
OUT
;reads input and determines whether or not it is a valid character
;Space?
LD R1, OPPOSPACE
ADD R1, R0, R1
BRz NEXTCHARACTER
;New line?
LD R1, OPPOLINE
ADD R1, R0, R1
BRz DONE
;Multiplication?
LD R1, OPPOMULTI
ADD R1, R0, R1
BRz DECODE
Brn INVALID_CHARACTER
;Exponent?
LD R1, OPPOEXPO
ADD R1, R0, R1
BRz DECODE
Brp INVALID_CHARACTER
;Is at most 9?
LD R1, OPPOCOLON
ADD R1, R0, R1
Brzp INVALID_CHARACTER
;Is it an apostrophe?
LD R1, OPPOAPOST
ADD R1, R0, R1
BRz INVALID_CHARACTER
;Is it a decimal point?
LD R1, OPPODECI
ADD R1, R1, R0
BRz INVALID_CHARACTER
;Operand or operator?
LD R1, OPPOZERO
ADD R1, R1, R0
BRzp PUSH
BRn DECODE
INVALID_CHARACTER .STRINGZ "Error invalid input"
BRnzp DONE
ERROR .STRINGZ "operation jumps are incorrect"
BRnzp DONE
;stores negation of operators in stack
DECODE NOT R0, R0
ADD R0, R0, #1 ;stores the opposite hex value
;figure out what operation to jump to
LD R1, ADDING
ADD R1, R1, R0
BRz ADDITION ;jumps to addition sequence
LD R1, SUBTRACT
ADD R1, R1, R0
BRz SUBTRACTION ;jumps to subtraction sequence
LD R1, MULTI
ADD R1, R1, R0
BRz MULTIPLICATION ;jumps to multiplication seq
LD R1, DIVIDE
ADD R1, R1, R0
Brz DIVISION ;jumps to division sequence
LD R1, EXPONENT
ADD R1, R1, R0
BRz EXPONENTIAL ;jumps to exponent sequence
Brnp ERROR
;pushes and pops characters into and out of the stack
PUSH ADD R6, R6, #-1 ;moves stack pointer up
STR R0, R6, #0 ;stores R0 at current spot
BRnzp NEXTCHARACTER
POP LDR R5, R6, #0 ;loads R6 into R5
ADD R6, R6, #1 ;moves stack pointer
;here are the operations
;R2 and R3 are operands R2 holds answer
ADDITION ADD R2, R5, #0 ;loads first number into R2
LDR R5, R6, #0 ;loads R6 into R5
ADD R6, R6, #1 ;moves stack pointer
ADD R3, R5, #0 ;loads second number into R2
ADD R2, R2, R3 ;stores answer in R2
ADD R6, R6, #-1 ;moves stack pointer up
STR R2, R6, #0 ;stores R2 in empty spot
BRnzp NEXTCHARACTER ;goes back to user input to read
SUBTRACTION ADD R3, R5, #0 ;loads number into R3
LDR R5, R6, #0
ADD R6, R6, #1 ;moves pointer
ADD R2, R5, #0 ;loads digit to be added into R2
NOT R3, R3
ADD R3, R3, #1 ;2's complement of R3
ADD R2, R2, R3 ;subtraction of the two numbers
ADD R6, R6, #-1 ;moves stack pointer up
STR R2, R6, #0 ;stores R2 in empty spot
BRnzp NEXTCHARACTER ;goes back to user input to read
MULTIPLICATION ADD R2, R5, #0 ;loads number to be multiplied
LDR R5, R6, #0
ADD R6, R6, #1 ;moves pointer
ADD R3, R5, #0 ;loads number to be multiplied
MULTIPLICATIONLOOP ADD R2, R3, R2
ADD R3, R3, #-1
BRp MULTIPLICATIONLOOP
ADD R6, R6, #-1 ;moves stack pointer up
STR R2, R6, #0 ;stores R2 in empty spot
BRnzp NEXTCHARACTER ;goes back to user input to read
;R1 will be a place holder here
;R4 will hold quotient
;R5 will hold remainder
;R2 is dividend
;R3 is divisor
DIVISION ADD R3, R5, #0 ;loads divisor
LDR R5, R6, #0
ADD R6, R6, #1 ;moves pointer after loading R5
ADD R2, R5, #0 ;loads dividend
NOT R1, R3
ADD R1, R1, #1
DIVLOOP ADD R4, R4, #1
AND R2, R2, R0
BRn NEGATIVE
BRp DIVLOOP
BRz ZERO
NEGATIVE ADD R4, R4, #-1
ADD R5, R2, R3
ADD R6, R6, #-1 ;moves stack pointer up
STR R4, R6, #0 ;stores R4 in empty spot
ZERO BRnzp NEXTCHARACTER ;goes back to user input to read
;R2 is exponent
;R3 is base and answer
;R4 is base copy
;R1 is base copy
EXPONENTIAL ADD R2, R5, #0 ;loads exponent into R2
LDR R5, R5, #0
ADD R6, R6, #1 ;moves pointer after loading R5
ADD R3, R5, #0 ;loads base into R3
ADD R1, R1, R3 ;loads base into R1
OUTEREXPOLOOP ADD R4, R1, #0 ;loads base into R4 for counter
INNEREXPOLOOP ADD R3, R3, R3 ;starts multiplication sequence
ADD R4, R4, #-1 ;decrements base counter
BRp INNEREXPOLOOP
ADD R2, R2, #-1 ;determines if needs to re-enter
BRp OUTEREXPOLOOP
ADD R6, R6, #-1 ;moves stack pointer up
STR R3, R6, #0 ;stores R3 in empty spot
BRnzp NEXTCHARACTER ;goes back to user input to read
DONE HALT
MULTI .FILL x002A
EXPONENT .FILL x005E
ADDING .FILL x002B
SUBTRACT .FILL x002D
DIVIDE .FILL x002F
OPPOSPACE .FILL xFFDF
OPPOLINE .FILL xFFF5
OPPOMULTI .FILL xFFD5
OPPOEXPO .FILL xFFA1
OPPOCOLON .FILL xFFC5
OPPOAPOST .FILL xFFD3
OPPODECI .FILL xFFD1
OPPOZERO .FILL xFFCF
STACK_START .FILL x5000
STACK_POINTER .FILL x5000
STACK_TOP .FILL x5050
OPPOSTART .FILL xAFFF
.END