28 Mar
2001
28 Mar
'01
7:05 p.m.
Date: Wed, 28 Mar 2001 19:36:07 +0100 (BST)
From: ard(a)p850ug1.demon.co.uk (Tony Duell)
Subject: Re: ZX80/81 expansion
Yah, the ZX80 couldn't think and talk at the same time so it blanked the
screen while it was processing! In the ZX81 this was known as FAST mode,
with the slower SLOW mode being able to do both. However, this still meant
that in SLOW mode the machine was 4 times slower than in FAST! Probably
sometime tonight I'll upload the Your Computer reviews of the ZX81, Jupiter
Ace and a couple of others for your reading pleasure, unless you've already
got them round somewhere. Oh, hang on, you're text only aren't you?
My ZX80 came with a ZX81 16K RAM pack and it
works fine;
ISTR physical
differences aside the only real difference
between the 80
and 81 was the ROM
I thought the ZX81 hardware provided some kind of interrupt
to the Z80 to
allow for 'simultaneous' processing and display, and that you
couldn't
get this on the ZX80 simply by dropping in the new ROM. There were
various circuits (a couple of TTL chips IIRC) to add this
feature to the
ZX80, though. Keyboard overlay I think. The keyboards were somewhat
different
physically, weren't they -- the ZX80 used contacts on the
main PCB, the
ZX81 had a separate membrane keyboard linked up with tapewire.
<thinks>. Yep. Looking at the pic on the museum site the keyboard is part of
the main PCB, whereas on the ZX81 it was separate. I still think its funny
to look at the design for the ZX80 and compare it with the heath-robinson
nature of the Issue 1 Spectrum :o)
I have an Ace, but it's not 'spare' if you
see what I mean.
Bugger :)
------------------------------
Date: Wed, 28 Mar 2001 22:21:07 +0000
From: jpero(a)sympatico.ca
Subject: Re: MacOS on CD-ROM? (was Re: Mac SE/30)
The biggest difference this Basilisk II is freeware where other
emulators you talked about ( saw them ) are payware.
I think I need to get my paws on that then......
--
Adrian Graham MCSE/ASE/MCP
C CAT Limited
Gubbins: http://www.ccat.co.uk (work)
<http://www.snakebiteandblack.co.uk> (home)
<http://www.binarydinosaurs.co.uk> (The Online Computer Museum)
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