🚀 go-pugleaf

In article <83986@tut.cis.ohio-state.edu> Jeff Martens <martens@cis.ohio-state.edu> writes:
>In article <1990Sep23.174736.16118@lavaca.uh.edu> jet@karazm.math.uh.edu (J. Eric Townsend) writes:

>>In article <924@ucsvc.ucs.unimelb.edu.au> U3364521@ucsvc.ucs.unimelb.edu.au (Lou Cavallo) writes:
>>>the discussion re: Virtual Memory/MMU/Protection reminds me of a tangentially
>>>related issue.  Some criticism of Amiga software (such as word processors) is
>>>related to the inability to deal with files/data larger than available memory.

>CP/M software, e.g., Wordstar, has been handling files bigger than
>memory (typically 64k) for years.  Basically, you have to handle
>paging yourself, which is inconvenient but not all that difficult.

But of course, it made quite a bit more sense on CP/M systems.  When you have
to cram program and data into 64K, things like manual paging to disk, program
overlays, etc. make alot of sense.  A basic Amiga these days has 1 Meg of RAM,
which is generally plenty for at least one wordprocessor or text editor and
a pretty large document.  And even with the application loaded, there's about
as much room in memory as on floppy disk.  Paging to hard disk would make 
more sense, but once you have a few megabytes of memory, it's extremely hard
to run out doing anything but the most memory intensive DTP kind of stuff,
or perhaps ray tracing, which for speed reasons might have problems with any
disk paging.

Not to say that it doesn't make any sense, just that it's not all that 
necessary in most Amiga applications, while you couldn't do anything serious
at all without it on a CP/M machine, and it's still quite important on many
MS-DOS applications, where you're still basically limited to 640K for both
program and data (you could of course add banked memory, like the CP/M
machines did, to help out a little).  What you really want is true virtual
memory, which makes the paging to disk transparent to every application.  But
you couldn't have that on every Amiga.  It should be possible to write a
swapping library that any application could easily use to swap data between
a disk file and a memory buffer.  It would be silly to have to create such a
mechanism more than once on the Amiga.

>-- Jeff (martens@cis.ohio-state.edu)

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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