Groups > comp.sys.acorn.programmer > #6216

Re: Getting extra memory

From	Bob Latham <bob@sick-of-spam.invalid>
Subject	Re: Getting extra memory
Newsgroups	comp.sys.acorn.programmer
Message-ID	<58ca53f83ebob@sick-of-spam.invalid> (permalink)
References	(1 earlier) <58ca23d0f5News03@avisoft.f9.co.uk> <58ca26a060bob@sick-of-spam.invalid> <58ca3a4a89News03@avisoft.f9.co.uk> <58ca3e1574bob@sick-of-spam.invalid> <58ca41c319News03@avisoft.f9.co.uk>
Organization	None
Date	2020-11-04 22:03 +0000

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In article <58ca41c319News03@avisoft.f9.co.uk>,
   Martin <News03@avisoft.f9.co.uk> wrote:
> In article <58ca3e1574bob@sick-of-spam.invalid>,
>    Bob Latham <bob@sick-of-spam.invalid> wrote:
> > In article <58ca3a4a89News03@avisoft.f9.co.uk>,
> >    Martin <News03@avisoft.f9.co.uk> wrote:
> > > In article <58ca26a060bob@sick-of-spam.invalid>,
> > >    Bob Latham <bob@sick-of-spam.invalid> wrote:

> > > > > Not sure what, if or how you have set workspace.
> > > > It starts out as just the "next" slot 640K.

> > > So how is the expression 'workspace' set to &8000+next ?

> > A perfectly reasonable question when eventually I understood it. For
> > some reason it didn't dawn at first.

> > There is a label in the assembler right at the end.
> > .workspace

> > It should then sit right above the assembled code.

> > So you'll now want to know O% and P% I presume?

> > P%=&40000:O%=&40000

> Are you saving the assembled code, then running the saved file?
> Or calling the code from within the BASIC?

> If the latter, then if your next slot is 640K, then &40000 is below
> that. When the code is executed, if a  7MB file is loaded at the
> end of the code, it will overwrite the end of the BASIC memory (as
> just below &80000+640k) and so the BASIC stack will be overwritten.
> This would cause problems when the called assembled code returns
> back to the BASIC program - hence the abort in the BASIC module.
> The assembled code will have saved the file ok.

As confessed elsewhere I had forgotten about HIMEM and written across
it. I was thinking that I'd left a good gap from the Basic source to
assembled code and I could then stuff the file I wanted to work on
directly on top of the code. It worked as well, to a fashion.

Anyway it's only a hobby, grateful to everyone who popped in to
advise and everyone was really nice too.

Thanks.

Bob.

-- 
Bob Latham
Stourbridge, West Midlands

Thread

Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 12:47 +0000
  Re: Getting extra memory Martin <News03@avisoft.f9.co.uk> - 2020-11-04 13:17 +0000
    Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 13:48 +0000
      Re: Getting extra memory Martin <News03@avisoft.f9.co.uk> - 2020-11-04 17:23 +0000
        Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 18:04 +0000
          Re: Getting extra memory Martin <News03@avisoft.f9.co.uk> - 2020-11-04 18:44 +0000
            Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 22:03 +0000
      Re: Getting extra memory druck <news@druck.org.uk> - 2020-11-04 18:06 +0000
        Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 18:33 +0000
  Re: Getting extra memory Steve Drain <steve@kappa.me.uk> - 2020-11-04 17:38 +0000
    Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 18:11 +0000
      Re: Getting extra memory Bob Latham <bob@sick-of-spam.invalid> - 2020-11-04 18:32 +0000

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