Technical information

Serial Solutions Aterm
Figure 8-8. Screen Output._______________________
;
test echo,echos ;Check echo
jz snd03 ;No echo to screen
;Echo to screen
mov xiobuf,al ;Store in buffer
xor al,al
mov xiobuff+1,al ;nul terminate
mov ax,fromecho
mov bx,offset xiobuf
call screen ;Output
mov al,xiobuf ;Get character back
snd03:
;
;
mov al,xiobuff ;Get character
mov si,offset inxlt ;input
call xlt ;translate
mov al,0
mov [di],al ;nul terminate
mov ax,fromport
mov bx,offset xiobuf
call screen ;Display character
;
;
badcmdmes db ’Cannot understand command:-’,newl,’ ’,0
.
.
mov ax,fromctrl
mov bx,offset badcmdmes ;Signal bad command
call screen
;
It can be seen that from assembly language serial ports are
comparatively easy to program, though the details of Aterm may
obscure this.
Page 140 Chapter 8