In the late '70's, I think the microcomputer market was highly simplistic
with respect to what it is today. Take a look at the comments I've imbedded
in your text below.
Dick
-----Original Message-----
From: Sellam Ismail <dastar_at_ncal.verio.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Friday, April 09, 1999 12:58 PM
Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit
51/4floppies)
>On Fri, 9 Apr 1999, Richard Erlacher wrote:
>
>> The TRS-80 could have been put out with (1) an 80x24 display rather than
the
<snip>
>> If Tandy had gone with the better design, which was on the
>> table, there probably would be no IBM PC today.
>
>This is a highly simplistic view of the early home computer market. He
>with the biggest dick didn't always go home with the babe. There was much
>more to the computer to entice someone to buy it than just the speed of
>the microprocessor. Available software and overall marketing effort
>played the bigger role, and Apple exploited this by advertising the figure
>of "Over 10,000 programs written for the Apple".
Yes, that's true, but, the 4MHz+ (4.9152 MHz, actually) Z-80B with 64K of
RAM, a 24x80-charcter display, double-density diskette interface that
actually worked, built-in capability to install a hard disk, AND the ability
to run CP/M right out of the box, in 1978-1979 e.g. at the fall '78 COMDEX,
which was BEFORE there were "Over 10,000 programs written for the Apple"
would have been hard to beat . . . particularly under the aegis of a
nation-wide company with these facilities under one management already in
place. Remember APPLE had to rely on small-time stores like Computerland
for distribution, and their service, mostly indirect, was slow and costly.
The things which seemed to make the Apple fit the business model the best
(before Visicalc) was the 24x80-character display and the 8" diskette drives
sitting next to it. With the aid of the Videx video display adapter and the
Sorrento Valley Associates' 8" disk drive interface, the machine suddenly
began to look like what people had come to expect when they learned about
computers and how to use them.
It's true that "He with the biggest dick didn't always go home with the
babe" but you mustn't forget that in this case, the dick was overtly
measured and advertised. Whereas the above described TRS80-III wouldn't
have been the fastest on the market, it had the packaging and the ability to
turn into much more computer for much less money than the Apple, though with
the gradually and later not so gradual increase in Apple's market share,
they were able to become somewhat more competitive in spite of the high cost
of distribution and service. The way it turned out, Tandy Corp ended up
with precisely the smallest, didn't it? A barely-over 2MHz processor which
stroked memory more at about 1.5 microsecond per memory cycle??? It was
obvious to everyone who used the Radio Shack model III that their computer
was SLOW. The Z-80-card in the Apple was significantly (and noticeably)
faster. The two machines otherwise occupied about the same desk space, and,
aside from the stupid, Stupid, STUPID choice to leave the Tandy machine's
display at 16 lines of 64 characters (about half of what was on a 24x80, and
about what was on an Apple with the standard display), they were quite
similar. Of course the Radio Shack machine was SLOW . . .
>As far as a comparison between the 6502 and Z80, its been argued over time
>and again, but the consensus is generally that each processor could
>perform some task faster than the other, and overall, applications running
>on both seemed to perform equally. Of course, when you involved
>subsystems like disk access, the Apple tended to have an advantage over
>some Z-80 systems (and even other 6502 systems).
I don't know that the assertions you make here are correct, but I don't
believe they're completely off-base. It's important to remember that if one
computer is not at least ~2x the speed of another, most tasks will seemingly
execute in more or less the same time as observed by a user at the console.
If two are set side-by-side and compared, the difference in performance
seldom amounts to the ratio of the clock speed or the ratio of the memory
access time. Often the result is totally counterintuitive. (Meaning
something's been overlooked!) Most of the time, it makes little difference.
Whether it takes four hours or six to handle the weekly payroll doesn't
matter very much if it's run at night.
>Sellam Alternate e-mail:
dastar_at_siconic.com
>---------------------------------------------------------------------------
---
>Don't rub the lamp if you don't want the genie to come out.
>
> Coming in 1999: Vintage Computer Festival 3.0
> See http://www.vintage.org/vcf for details!
> [Last web site update: 04/03/99]
>
Received on Fri Apr 09 1999 - 15:01:36 BST