ASM Community

ROM_BIOS_DATA is a structure not a data.

pentagenius
RTFM masmref
try change

buffer dw 16

on

buffer dw 16 dup (?)

rotivc,
he defined a segment at : ROM_BIOS_DATA SEGMENT at 40h
Segment and struct always end with ENDS keyword.

hm..is that a com file u tryto code?
than use this template:

.MODEL  TINY

.CODE

ORG     100H

START:  JMP     INIT







INIT:



        INT     20H



END     START

pentagenius,
this1 works:

ROM_BIOS_DATA equ 40h	

Buf_head	equ	1Ah	; (0040:001A=0) ;"Head"

Buf_tail	equ	1Ch	; (0040:001C=0) ;"Tail"

Kb_bufstart	equ	80h	; (0040:0080=0) keyboard buffer offset start address(1Eh)



.286

.model tiny

option segment : use16



.code

	org	100h

	assume ds:@code, es:nothing, ss:nothing 

Start:

	jmp	Start1

head dw ?

tail dw ?

buffer dw 16



Start1:

		assume	ds:nothing

		mov	bx, ROM_BIOS_DATA	 ;[B]NO[/B] Showing error in this line

		mov	ds, bx

		assume	ds:@code

		;search for an previously installed copy of bds program

		cld

		not	byte ptr Start		; modify to avoid false match

		xor	bx, bx			; start search at segment zero

		mov	ax, cs			; compare to this code segment

                mov     ds, ax	

next_segment:

		inc	bx			; look at next segment

		mov	cx, 32			; 64 bytes must match

		cmp	ax, bx			; until reaching this code seg

		mov	es, bx

		je	loaded

		mov	si, 100h		; setup to compare strings

		mov	di, 100h 		; 100h -> offset Start

		rep	cmpsw			; compare ds:si to es:di

		test	cl, cl			; did the strings match?

		jne	next_segment		; if no match, try next segment

loaded:

		;...

		mov	 ah, 4Ch		; exit to dos

		int	 21h

End Start

here is my old post:

Don't mix 16bit MASM (DOS) code and 32bit MASM (Windows) code
Here is an example wih 16 bit MASM(DOS) code.
You should use older tools (MASM compiler and linker) too

We will create 16 bit DOS EXE file test.exe with Make16e.bat
It is the contents of the test.asm file

.model small

option segment:use16



;It is EXE file

;dseg segment para public 'data'

.data

str1 db 'Hello world','$'

;dseg ends



;sseg segment para public 'stack'

;sseg ends

.stack



.code

;cseg segment para public 'code'

;assume cs:cseg;, ds:dseg



_start:

        mov ax, @data ;$dseg

        mov ds, ax

        mov es, ax

        mov dx, offset str1

        mov ah, 9

        int 21h

        mov ah, 4ch

        int 21h

;cseg ends

end _start

We will create 16 bit DOS COM file test1.com with Make16c.bat
It is the contents of the test1.asm file

.model tiny

option segment:use16

; It is COM file

;sseg segment para public 'stack'

;sseg ends

;.stack



.code

;cseg segment para public 'code'

;assume cs:cseg, ds:cseg, es:cseg 

        ORG 100h

_start:

        mov ax, cs

        mov ds, ax

        mov es, ax

        mov dx, offset str1

        mov ah, 9

        int 21h

        mov ah, 4ch

        int 21h

str1 db 'Hello world','$'



;cseg ends

end _start

Here is the contents of the Make16e.bat file

@echo off

rem create exe file

\masm32\bin\ml1 /c /Zm  /nologo test.asm

\masm32\bin\link16 /nologo test.obj,,,,,



if exist test.obj del test.obj

if exist test.map del test.map

Here is the contents of the Make16c.bat

@echo off

rem create com file

\masm32\bin\ml1  /c /Zm /AT /nologo test1.asm   

\masm32\bin\link16  /TINY /nologo test1.obj,test1.com,,,,

if exist test1.obj del test1.obj

if exist test1.map del test1.map

Where:
- ml1.exe is MS MASM compiler ver. 6.14
- link16.exe is the old MS Linker ver.5.60
You can download it from:
ftp://ftp.microsoft.com/ softlib/mslfiles/lnk563.exe
start it and next rename the link563.exe to link16.exe

To create 32bit MASM (Windows) code with the newer tools
just take a look in your MASM32 directory and forget about Int 21h.


Regards,
Lingo

Tenkey, Lingo12 thanks a lot to both of you.
That really helped.:grin: