16 bit .com binary for MSDOS - 31 Bytes (112 Byte NASM Source)

c:resw 1
mov dx,c
mov cx,1
r:
mov ah,63
mov bx,0
int 33
cmp ax,0
je e
mov ah,64
mov bx,1
int 33
jmp r
e:
int 32

Build with "nasm -f bin -o cat.com cat-msdos.s".

I already provided a solution for x86_64 Linux, but was unable to get it under 100 bytes. This is over 100 bytes of assembly, but the actually binary is only 31 bytes! This must be the simplest solution here.

16 bit .com binary for MSDOS - 31 Bytes (112 Byte NASM Source)

00 00 BA 00 00 B9 01 00 B4 3F BB 00 00 CD 21 83 F8 00 74 09 B4 40 BB 01 00 CD 21 EB EB CD 20

The nasm source code:

c:resw 1
mov dx,c
mov cx,1
r:
mov ah,63
mov bx,0
int 33
cmp ax,0
je e
mov ah,64
mov bx,1
int 33
jmp r
e:
int 32

Build with "nasm -f bin -o cat.com cat-msdos.s".

I already provided a solution for x86_64 Linux, but was unable to get it under 100 bytes. This is over 100 bytes of assembly, but the actually binary is only 31 bytes! This must be the simplest solution here.