Category : Utilities for DOS and Windows Machines
Archive   : HISTORY.ZIP
Filename : SETUP.ASM

dataseg segment para public 'data'
extrn lineoff_:word,lineseg_:word
extrn $MEMRY:word
pgmstack dw ?
dataseg ends

codeseg segment para public 'code'

public setup_
extrn getline_:near

old21 dd ?
holdax dw ?
holdss dw ?
holdsp dw ?
holdds dw ?

setup_ proc near
assume cs:codeseg,ds:dataseg
mov dx,$MEMRY
add dx,10fh
and dl,0fff0h
mov pgmstack,dx

mov ax,3521h ;save old interrupt 21 vector
int 21h
mov word ptr old21,bx
mov ax,es
mov word ptr old21+2,ax

mov ax,2521h ;set new interrupt vector
mov dx,offset ngbuf
int 21h

mov dx,pgmstack
mov cl,4
shr dx,cl
mov ax,3100h ;terminate and stay resident
int 21h
setup_ endp

ngbuf proc far
pushf
cmp ah,0ah ;buffered input?
jz ngbuf1
popf
jmp old21

ngbuf1: mov cs:holdax,ax
mov cs:holdss,ss
mov cs:holdsp,sp
mov cs:holdds,ds

mov ax,cs ;set up ds
mov ds,ax

cli ;no ints while messing with stack
mov ss,ax
mov sp,pgmstack
sti ;ok, now you can interrupt

push bx ;save regs
push cx
push dx
push si
push di
push bp
push es

mov ax,holdds ;set up for getline
mov lineseg_,ax
mov lineoff_,dx
call getline_

pop es
pop bp
pop di
pop si
pop dx
pop cx
pop bx

cli ;no interruptions please
mov ss,cs:holdss
mov sp,cs:holdsp
sti ;ok to interrupt again

mov ds,cs:holdds
mov ax,cs:holdax
popf

iret

ngbuf endp

codeseg ends

end