Re: Coding for IIgs?

["Charlie" <charlieDOTd@verEYEzon.net>]

"lyricalnanoha" <lyricalnanoha@usotsuki.hoshinet.org> wrote in message 
alpine.DEB.0.99.0812241421001.24180@andisteele.dosius.ath.cx">news:alpine.DEB.0.99.0812241421001.24180@andisteele.dosius.ath.cx...

>SNIP<

>
> One usually considers the highest-level stuff as needing to be loaded from 
> disk, but it would seem with the IIgs that the high-level stuff is in ROM, 
> and only the low-level stuff needs to be pulled from disk!

Well, the IIgs has much of the toolbox in ROM but as new tools were added 
and old ones patched more and more ended up being loaded from disk.  I also 
doubt that the ROM 3 and ROM 1 have the same entry points for the toolbox 
routine (not sure about that) since all tool calls are done through a table 
that is set up initially.
The really low-level stuff is done pretty much like you are used to with any 
other Apple II.  Stuffing stuff in registers and banging on softswitches.

>
>> The toolbox routines can be accessed without GS/OS.  I believe a few can
>> even be accessed in 8-bit mode (or maybe not :-).  One thing you have to 
>> be
>> careful with is that some (most) of the toolsets are dependant on other
>> toolsets so they have to be loaded/initialized in order before being 
>> used.
>
> Easy enough to switch to 16-bit mode, call the toolbox, drop to 6502 mode, 
> not?

Yes but...

Many (but not all) the toolsets require initialization which can mean 
allocating memory for their own stack space and zero page (called direct 
page in GS speak).  This space can only reside in bank $00.  If you are not 
using the memory manager then you would have to be real careful that you 
weren't stepping on your program.

>
>>
>> You might want to take a look at some of Bob Sander-Cederlof's later 
>> Apple
>> Assembly Line stuff.  If I remember correctly, He did some Apple IIGS
>> programming without using ProDOS-16 or GS/OS.
>
> I'll look around there.  I read that site a lot.
>
>> I would also strongly suggest that you read the IIGS hardware and 
>> firmware
>> references.
>
> I've been looking, and will continue to.
>
> -uso.

Good luck.  It sounds like neat project and a good way to learn the ins and 
outs of an Apple IIGS.

Charlie