diff options
Diffstat (limited to 'cmpen472hw12_McDonnell/Sources/main.asm')
| -rw-r--r-- | cmpen472hw12_McDonnell/Sources/main.asm | 48 |
1 files changed, 38 insertions, 10 deletions
diff --git a/cmpen472hw12_McDonnell/Sources/main.asm b/cmpen472hw12_McDonnell/Sources/main.asm index 3abe95a..a5935af 100644 --- a/cmpen472hw12_McDonnell/Sources/main.asm +++ b/cmpen472hw12_McDonnell/Sources/main.asm @@ -98,10 +98,6 @@ pgstart lds #$3100 ; initialize the stack pointer jsr WriteString ; Write the string to the serial console mainLoop - ldx #$3000 - ldy #$0100 - jsr MDCommand - ldx #buffer ; Load the address of the buffer into X ldy lenBuf ; Load the length of the buffer into Y jsr Zeros ; Fill the buffer with zeros @@ -151,16 +147,18 @@ CheckInput pshd ; Save D to the stack ldaa 1,x+ ; Read Character from the string in X cmpa #'W' ; Compare Character to 'W' - beq cWrite ; If A == 'W', branch to cWrite + lbeq cWrite ; If A == 'W', branch to cWrite cmpa #'Q' ; Compare A to 'Q' - beq cTypeWrite ; If A == 'Q', branch to cTypeWrite + lbeq cTypeWrite ; If A == 'Q', branch to cTypeWrite + cmpa #'M' ; Compare A to 'M' + beq cMDCommand ; If A != 'M', Check if MD command cmpa #'S' ; Compare A to 'S' - bne cUnknownCMD ; If A != 'S', Command unknown + lbne cUnknownCMD ; If A != 'S', Command unknown ldaa 0,x ; Load next character but don't increment cmpa #'$' ; Compare A to '$' - bne cUnknownCMD ; If A != '$', branch to unknown command + lbne cUnknownCMD ; If A != '$', branch to unknown command jsr ReadHex ; ReadHex to Read the memory Address - beq cBadAddr ; If Z == 1, branch to cBadAddr + lbeq cBadAddr ; If Z == 1, branch to cBadAddr exg Y,X ; Exchange Y for X pshx ; Save X to the stack ldx #buffer ; Load address of buffer into X @@ -168,6 +166,33 @@ CheckInput jsr Zeros ; Fill buffer with Zeros pulx ; Restore X from the stack bra cDone ; branch always to cDone +cMDCommand ldaa 1,x+ ; Load next character into A + cmpa #'D' ; Compare do 'D' character + bne cUnknownCMD ; If A != 'D', unknown command + ldaa 0,x ; Load next character but don't increment + cmpa #'$' ; Compare A to '$' + bne cUnknownCMD ; If A != '$', branch to unknown command + jsr ReadHex ; ReadHex to Read the memory Address + beq cBadAddr ; If Z == 1, branch to cBadAddr + exg Y,D ; Exchange Y and D + pshd ; Save D to the stack +mSkipSpaces ldaa 1,x+ ; Load next character into A + beq cBadData ; If A == 0, branch to bad Data (no data given) + cmpa #' ' ; Compare A to space character + beq mSkipSpaces ; While A == ' ', loop to skip spaces + cmpa #'$' ; Compare A to '$' + bne cBadData ; If A != '$', branch to cBadData + dex ; Decrement X by 1 + jsr ReadHex ; Jump to ReadHex to read hex data + beq cBadData ; If Z == 1, branch to cBadData + puld ; Restore D from the stack + exg D,X ; Exchange D and X + pshd ; Save D to the stack, cBadData usually has 2 D's on the stack + cpy #2 ; Compare Y to 2 + blo cBadData ; No distances below 2 bytes + puld ; Restore D from the stack + jsr MDCommand ; Jump to MDCommand + bra cNoPrint ; Done with command cWrite ldaa 0,x ; Load next character but don't increment cmpa #'$' ; Compare A to '$' bne cUnknownCMD ; If A != '$', branch to unknown command @@ -192,7 +217,7 @@ cWriteData puld ; Restore D from the stack exg D,X ; Exchange D and X sty x ; Write data in Y to memory in X cDone jsr PrintMem ; Jump to PrintMem to print the contents of the location - puld ; Restore D from the stack +cNoPrint puld ; Restore D from the stack pulx ; Restore X from the stack rts ; Return to caller cBadAddr ldx #badAddr ; Load the address of badAddr into X @@ -818,6 +843,9 @@ twMsg dc.b 'Welcome to Type Writer, you may type below.',CR,LF ; msg: this is the main option menu string msg dc.b 'S: Show the contents of memory location in word',CR,LF dc.b 'W: Write the data word (not byte) to memory location',CR,LF + dc.b 'MD: Display the contents of continuous memory locations',CR,LF + dc.b 'LD: Load a block of data to continuous memory locations',CR,LF + dc.b 'GO: Run the program at the specified memory location',CR,LF dc.b 'QUIT: Quit the main program, run Type writer program.',CR,LF,NULL end ; last line of the file |