Re: Apple IIGS ROM listings and a general OS question

[James Gray <jamesg@alaska.net>]

The IIGS has a single entry point for the built-in tools that handle
quickdraw, menus, etc. An interesting point is that some of the ROM code
isn't used anymore. It is loaded from new code on the system disks.

The entry point is at $E10000. The X register has the tool set number and
function in the tool set being called. The stack has space for result and
paarameters for the call.

I think all the games did their own drawing and skipped Quickdraw.

- James - [IMAGE]

Lyndon Fletcher wrote:

> Hi,
>      I was wondering if there was an annotated ROM listing of the
> Apple IIGS ROM. I am aware that Apple never publically printed the ROM
>
> A second question. I have been told that GS/OS allows hardware
> abstraction (ie a compliant app can access all system resources though
> the OS and does not need to know about the underlying HW) how complete
> is this abstraction? Do most programs use it or do they bit-bang the
> physical hardware locations??
>
> Lyndon