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From: jan@janhh.hanse.de (Jan Willamowius)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: How does one write a GDOS driver?
Message-ID: <1334.05.91@janhh.hanse.de>
Date: 9 May 91 07:13:58 GMT
Article-I.D.: janhh.1334.05.91
References: <91127.132420ONM07@DMSWWU1A.BITNET>
Lines: 32

Julian F. Reschke writes:
> Jeff Gruszynski says:
>>
>>        I'm trying to find information on how to write a GDOS device
>>        driver from scratch.
>
> Basically, you have to rewrite a whole new vdi. If you are familiar with
> assembler, you should take a look at the trap dispatcher at the beginning
> of META.SYS

I don't quite agree. What you need is a trap dispatcher. True.
Meta.Sys is a good example for that.

Secondly, you need the code for all the functions to set and inquire
parameters. That code is basically the same for all devide drivers.
(From what I understand Atari supplies it with the GDOS Drivers Kit,
which costs about $300.) If you're not rich take a look into some device
driver. It's all in there.
(BTW: The *old* versions have a symbol table!)

What you have to write yourself is the code for the actual output.
A dot matrix printer has to buffer te output for a whole page.
It draws on a bitmap and then prints it. A plotter probalby is able to
do the drawing right when it gets the command.

Good luck,
           Jan


--
Jan Willamowius, Nienredder 6, 2000 Hamburg 54, Germany
E-Mail: jan@janhh.hanse.de