printing a character

[rxbagain]

First, word and byte are both reserved words (data types) in assembly and you should not redefine them. You're lucky? you did not get an error in your typedef.

Second, byte accepts values of up to 0FFh only. Again, you're lucky? if you did not get any error in your j and k declarations

The "OPERAND TYPES DO NOT MATCH" is in "mov ax, j". j is a byte (1 byte) and you are trying to copy it to a WORD register (2 bytes) and so the assembler is complains about type mismatch.

Edit: you should use "CALL" in using a function (e.g. call putc). Also, you have to be careful in passing parameter as well as the calling convention used by the function (e.g. _cdecl, _stdcall, _pascal, etc.) to avoid stack corruption.