[ont.micro.mac] My

info-mac@utcsrgv.UUCP (info-mac) (05/04/84)

Date:     Wed, 2 May 84 15:14 PST
From: John Palevich <uw-beaver!palevich%atari.csnet@csnet-relay.arpa>
To: info-mac@sumex-aim.arpa
Subject:  My (educated) opinion on the Mac's design

The following is the personal opinion of John Howard Palevich, and is
not ment, in any way, to reflect the opinion or knowlege of either Apple
Computer Inc or Atari Inc.  It is based entirely upon publicly available
information.

Hi -- I worked on a high-end personal computer design team for a couple of
months once, and I think you're all going off the deep end with your Mac
speculations.  Please remember that Apple is just an ordinary company
composed of fallible, short-sighted engineers.  The Mac design is great,
but it's not part of some grand all-encompassing plan.  In particular:

	The Mac will not have color.  Ever.  Give it up, guys. (More on this
later...)

A Mac designer gave an excellent talk at Stanford a while back, during which
he gave a bit of the history of the Macintosh:

Remember that the Mac project has been around for a very long time.  The
original Mac had:

 * a 256 x 256 bit-mapped display
 * 64K of RAM
 * a 8-bit (6809?) processor
 * integrated application software in ROM
 * transportability (original design looked like an Osbourne)
 * a "twiggy" (Lisa-1 style) disk drive

The Mac was (obviously) ment to be a "model-T" machine, with no options.

Anyway, they realized that the ability to display 80-column text was an
absolute necessity, so they went to a 320 x 256 display.  The 4 x 6 characters
that this display produced proved so ugly that they gave up and went to the
current 512 x 342 display, which gives an adequate 6 x 8 character size.

A 512 h by 342 v by 1 bit-per-pixel by 60 hz display requires 22K of RAM and
a video memory bandwidth of abou 2Mb per second.  If you want your processor
to have any access to video memory at all, you have to use a 16 bit data bus.
(All other things being equal, a 16-bit bus transfers data twice as quicly
as an 8-bit bus.)

Sixteen 64K-by-1 RAM chips give you 128K of RAM, and by this time the 68000
had become cheap, and was being used on the Lisa project, so they adopted it.
  
Inspection of the "Inside Macintosh" manual, "User Interface Guidelines", page
67, dated 10/11/82, reveals a Macintosh which is pretty similar to the one we
know today.  The only difference is that the disk drive's capacity is rated
as 840K.

WHY WE HAVE ONLY 400K ON OUR DISKS

The Mac was designed to use the fabled "Twiggy" drives. These drives, designed
for the Lisa computer, use 5 and 1/4 inch diskettes, store 840K by using both
sides of the diskette surface, and have a reputation for being unreliable.

Halfway through the Mac project, they decided to go with the fancy new Sony
3 and 1/2 inch drives for a number of reasons which can only be guessed at.
I suspect that influencing factors included:
 * Sony diskettes could store the same ammount of data as the Twiggy drives
 * Sony hardware is superb
 * Sony hardware is cheap
 * The diskette's physical format was becomming a standard

This design change was made late in the game -- Apple had already made the
molds for the Mac cases with the larger cut-outs for the Twiggy drives.  If
you look at the photos on pages 128 and 130 of the "Premier" issue of Macworld,
you'll see Macintoshs with the larger cut-outs.

The only problem was that Sony couldn't make double sided drives in quantity,
so we're stuck with single sided, 400K drives for a year or two.

WHAT DO YOU MEAN, NO COLOR?

Just that.  Quickdraw has a tiny little hook in it for drawing on multiple
bit-planes, and this might be of some use in preparing bit-maps for displaying
multiple colors on a color printer.  But that's it.  The Mac is steeped in
software concepts developed solely for high resolution black-and-white
displays.  Nobody has shown that color is useful for Mac-type applications,
and high resolution color monitors are extremely expensive. ($600 for RGBI,
MUCH more if you want grey scale.)

Color is superb for games and for pictures, but it requires a vast ammount of
RAM, computational power, custom display chips, and expensive monitors.  In
ten years, everyone'll have a color display, but right now, for a software-
intensive, cheap, personal computer, black & white is the way to go.

RUMORS, RUMORS, RUMORS

Careful inspection of the "Inside Macintosh" documents yields some titilating
odds & ends.  On page 30 of the "User Interface Guidelines", under Desk
Accessories, a list of standard desk accessories are given, including:
"Telegram Form and In-Box (AppleGram)".  I think that this is the tip of the
AppleNet iceberg.

In the "Application" section, a printout of some sample application programs
are given.  These printouts are probably from an Apple laser printer.  One
tell-tale mark of a networked laser printer is the print-job sepereator, a
visual mark printed on the paper to indicate the start of a new print-job.
The grey bar running down the right hand side of the first page of each of
the listings serves this purpose.  (Goodness, it also looks like QuickDraw
was used to scan-convert for the laser printer page.  My, but a general-
purpose set of bit-map routines is useful!)

Although there is absolutely no economic reason for Apple to make a LCD display
for the Mac, it's not much harder than the one they're trying to make for the
Apple IIc.

The Apple IIc has two serial ports and a mouse port, just like the Mac.  At
least the company is being consistent in it's belief that the user really
doesn't need expansion slots.

WHAT DOES IT ALL MEAN?

1) The Mac's a pretty nifty machine.

2) Apple will make a great deal of money.

3) The guy on the wall-screen in the Mac commercial is more likely to be Mr.
Jobs than any of his competitors.  After all, the Mac screen is black & white,
while the IBM PC is color. . . .