At this time I didn't make any adaptions to the driver for Watcom compatibility.
MASM5.10A is bundled with various ddk samples and I don't have any idea which 
watcom parameters would be necessary for such a device driver. So I used MASM
and LINK5.10.005. I used nmake from the ddk-tropez driver. Path in makefile 
have to be adopted. 

I've made only two changes to Holgers original source -

1) 	Alger Pike in 'EDM/2 - A Hello World Device Driver' wrote changing qword 
	to fword is necessary. I didn't check this by myself but MASM 5.10A gives 
	a warning with qword, so I thought changing	to fword wouldn't harm. 
221c221
< 		sgdt	qword ptr [gdtsave]		; access the GDT ptr
---
> 		sgdt	fword ptr [gdtsave]		; access the GDT ptr

2)	offset removes another MASM warning. 
277c277
< 		add	bx,iotbl	; add offset
---
> 		add	bx,offset iotbl	; add offset


This are the tools I used to make the driver -

[E:\C\FastIO\driver]nmake

Operating System/2 Program Maintenance Utility
Version 4.00.000 May 12 1999
Copyright (C) IBM Corporation 1988-1999
Copyright (C) Microsoft Corp. 1988-1991
All rights reserved.

        masm -MX -T -N fastio_a.asm;
        masm -MX -T -N fastio_c.asm;
        E:\c\tropez\ddk\base\tools\link /MAP /NOI /NOE /nod /exepack /packd /a:1
6 /far fastio_a.obj fastio_c.obj,fastio.sys,,E:\c\tropez\ddk\base\lib\os2286.lib
 E:\c\tropez\ddk\base\lib\os2286p.lib P:\MSC_51\LIB\SLIBCE.LIB,fastio.def

Microsoft (R) Segmented-Executable Linker  Version 5.10.005
Copyright (C) Microsoft Corp 1984-1989.  All rights reserved.

        mapsym fastio.map

Operating System/2 Symbol File Generator
Version 4.00.000 May 12 1999
Copyright (C) IBM Corporation 1988-1999
Copyright (C) Microsoft Corp. 1988-1991.
All rights reserved.


No entry point, assume 0000:0100
.

