Stack Depth requirements for CP/M 2.2 CBIOS

[Roy J. Tellason]

On Saturday 31 January 2009 11:56:56 am Allison wrote:
> >Subject: Stack Depth requirements for CP/M 2.2 CBIOS
> >   From: "ROBO5.8" <robo58 at optonline.net>
> >   Date: Fri, 30 Jan 2009 19:08:49 -0500
> >     To: "'General Discussion: On-Topic Posts Only'"
> > <cctech at classiccmp.org>
> >
> >Hello,
> >
> >I have rewritten my old systems CP/M 2.2 CBIOS to add an IDE Drive.
> >
> >I've run into a problem that has me stumped.  Everything works as long as
> > I don't try and copy or assemble a large Assembly file (>80KB).
> >
> >I will be going along fine and then out of nowhere I will see CP/M request
> >access to Drive "T".  My debug info says SELDSK is requesting Drive
> > 0FF00h.
>
> Ok this is easy.  CP/M 2.x (2.2 nominal) can only address 16 logical drives
> so that's limitation one.  Each drive is limited to 8Mb
> (65525sectors*128bytes).
>
>
> If you use one of the CP/M like imperoved work a likes this is less an
> issue and logical drives can be much larger (up to 1gb).

I thought I'd remembered CP/M 3 going up to 32MB (but I could be wrong about 
that),  which ones go further?  I've not ever heard of any going up to 1G 
before.



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