Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwvax!astroatc!nicmad!madnix!aaron
From: aaron@madnix.UUCP (Aaron Avery)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Virtual Memory
Message-ID: <663@madnix.UUCP>
Date: 25 May 89 03:08:46 GMT
References: <8905222150.AA05890@jade.berkeley.edu> <6959@cbmvax.UUCP>
Reply-To: aaron@madnix.UUCP (Aaron Avery)
Organization: ASDG Incorporated
Lines: 26

In article <3866@sugar.hackercorp.com> karl@sugar.hackercorp.com writes:
>There are huge memory applications forthcoming, however.  A 4000X4000 24-bit 
>plane image (good enough to record with sub-film grain resolution onto 70 mm
>film, I believe) takes up 48 megabytes.  Of course you'll want to keep it 
>entirely in RAM -- accessing it via VM into a few meg would take an 
>excruciatingly long time.  You'll want an undo buffer, too.

Waddaya mean, forthcoming? We've encountered this problem. That's why the next
release of Professional ScanLab will have its own virtual memory support. And
accessing those 48 Megs won't be too bad with 8 Megs of fast ram in the
machine.
For most people, they'll be doing smaller images (say 10 Megs), and two megs
of memory would be sufficient.
Even without VM, ScanLab is very useful for most standard printing
applications (paper, not film) on a 9 Meg A2000.

The biggest problem with demand paged VM on the Amiga currently is the
Disable() problem. It would also make Forbid() even naughtier, since you could
lock out other tasks (this includes things like timer.device) for an entire
hard drive access.

-- 
Aaron Avery, ASDG Inc.         "A mime is a terrible thing to waste."
                                                             -- Robin Williams
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