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assemblyx86serial-porttasm

Regarding Serial Communication with assembly code 8086

On using INT 14H, AX gets set to 600FH and on using the code to send transmit a character, the AH gets set to 80H. I am using DOSBOX-SvnDaum to run Tasm.How should the time out error be resolved? Following is the code....

.MODEL small
.STACK 100h
.data
.code
_start:
mov ax,@data
mov ds,ax
mov ah, 0           ;Initialize opcode
mov al, 11100011b   ;Parameter data.
mov dx, 0           ;COM1: port.
int 14h
again:
   mov  dx, 0           ;Select COM1:
   mov  al, 'm'        ;Character to transmit
   mov  ah, 1           ;Transmit opcode
   int  14h
   jmp again   
mov ah,1
int 21h
END _start
Solution

  • You can't access COM ports directly via 16bit DOS programs running inside Windows.

    Here are your options:

    1. Use a COM proxy like this one.

    2. Install a virtual box and run your programs on it under DOS operating system.