On Mon, Sep 01, 2008 at 11:35:51PM -0700, Eric Smith wrote:
Rick Murphy wrote:
Getting something as simple as Adventure fit onto
the PDP-8 was a lot
more work than I'd like to admit. Anything more complex is out of the
question.
The early Infocom games ran fine on computers with 32K*8 RAM...
Did they? My first direct experiences with Infocom games were on
the Apple II and C-64 (c. 1982-1983). I'd seen them once or twice
before, but I only really got my hands onto them when I could run
them at home. There weren't very many 32K Apple IIs - yes, they
were sold, but the ones I saw were always expanded to 48K. The
first C-64 interpreter didn't twiddle any of the memory banking,
so it used the same memory space available to BASIC - 39K (it didn't
even use the RAM block at $C000 - at one point, I loaded a PET font
that I copied from a real PET ROM up there to get "cleaner" letters
than the standard C-64 ROM font while I played).
... so 32K*12 should work fine.
I think it should fit as well.
With more aggressive paging and a suitable disk, even
the larger games
should work. The official interpreters never page the impure data, but
there's no reason an interpreter can't do that.
Yes... as you say, one _can_ page impure data. Given the slow performance
of any of the 8-bit paged intepreters, I have to admit that I didn't think
of that at first, but it would work, though slowly.
On the slowest platform I know, a C-64 w/1541 disk, it used to take many
seconds between commands just to page in the _pure_ data. The TRS-80 and
Apple II had much faster diskette interfaces, so were more limited by the
speed of the media and the speed of the stepper, unlike the 1541 (which
had those limitations as well, but the serial interface was the real
bottleneck). I don't have any performance data, but I don't remember
my RL01 being particularly slow on my PDP-8/a - certainly much faster than
floppies.
Thanks for pointing out what should have been an obvious path around
memory limitations. It's given me a bit more to think about.
-ethan
--
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Ethan.Dicks at
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