Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!cbatt!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: net.micro.apple
Subject: Re: C128 vs Apple //e
Message-ID: <284@neoucom.UUCP>
Date: Sat, 27-Sep-86 12:21:43 EDT
Article-I.D.: neoucom.284
Posted: Sat Sep 27 12:21:43 1986
Date-Received: Tue, 30-Sep-86 04:52:20 EDT
References: <9800030@uiucuxa>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 43
Summary: cpu clock speed faster in c128

[Line eater, get me.]

Hi,

It's been a while since I was dabbling on a c128.  I do remember,
though, that under certain circumstances the cpu on the  c128 is
run at 2.04 MHz, rather than the "standard" 1.02 MHz.  Don't quote me
on this, but I think it was durring the CRT retrace times that the
cpu is running faster on the c128.

Naturally, Commodore wasn't first to cook the idea up.  Remeber the
ill fated Apple III ran its cpu faster in the CRT retrace time.

Comparing the c128 and apple II against the IBM pc is interesting,
as in the normal precision mode, the IBM basica only carries 6 -7
digits of accuracy while apple and commodore carry typically 10-11
digits.

Scrolling text on the 80 col screen is where the speed of the apple
IIe is really sapped since the poor cpu has to do handstands to
move the text around in the oddball memory map.  (I wrote a
subroutine in machine language to scroll down to augment the built
in code that scrolls up.)  I've always wondered why a decent text
memory map wasn't designed in to the Apple II at the outset, as
even in 1976, it would have added less than $5 to the cost of the
components in the machine.

I saw a review of the new //GS on TV, and they were loading an
image, and it came up with the familiar fill-in-between the lines
fashion of the II.  Perhaps this was just done for "effect" to
disolve the screen.  I sure was hoping the GS would have a mode
with a contiguous bit map to make manipulations easier (and
faster).  Perhaps, the 128K quickdraw ROM in the GS will be a
relief, and I won't have to do the dogwork of figuring out how to
make the hardware dance nicely.

  --Bill

Bill Mayhew
Division of Basic Medical Sciences
Northeastern Ohio Universities' College of Medicine
Rootstown, Ohio  44272  USA    216-325-2511
(wtm@neoucom.UUCP)