Subject: The NOVA and the PDP-11 (Was Re: WANTED: PDP-10 or 11)

From: [email-masked] (Charles Lasner)
Date: Sun, 6 Dec 1992 21:47:58 GMT

In article <[email-masked]> [email-masked] (Don Stokes) writes:
>
>> >True.  Data General is interesting to DECaholics because of its origins;
>> >earlier DG machines are in some ways what DEC machines might have been.
>> 
>> It is interesting that Tracey Kidder steered away from this issue in the
>> Soul of a New Machine book.  Perhaps we should state our own versions of
>> the tale as we see it.
>
>Well, my version of the tale, gleaned from multiple sources (including
>Kidder) goes something like this:
>
>Edson de Castro worked on the PDP-8.  When the call came for a 16 bit
>machine, de Castro's group started work on what amounted to a 16 bit PDP-8
>(single word, single operand instructions, word oriented addressing etc).

Edson de Castro was Chief Engineer of the original negative logic PDP-8.  He
wanted to work on the newer TTL that had just emerged as the obvious 
direction the industry was going in, and had little interest in the PDP-8/i
project; he wanted something more challenging, such as a 16-bit machine that
was in the "family" of machines such as the -8, but newer hardware.  Apparently
his "group" was as large as several hundred people working on what amounts to
the NOVA as it became known later.  Also, this design was partially serial,
and thus vaguely reminiscent of this notion as carried out in the PDP-8/s,
a losing totally serial version of an -8 that wasn't entirely compatible with
it, and as such, is incapable of running the vast majority of PDP-8 software
no matter how slowly it attempts it, etc.  (It is curious that even years
later there was a NOVA micro that was two-bit serial on the outside.  These
guys are hung up on the trade-off towards non-parallel designs!).

Some quirky aspects of the NOVA are taken straight from the PDP-8, such as
the special disposition of the auto-index registers, etc., so yes, the
short-form of this discussion could be that the design was for a 16-bit
follow-on to the PDP-8 family.

>
>Sometime after de Castro's group got started, another development got under
>way, developing a 16 bit architecture with a multiple word two-operand
>instruction set and half word oriented addressing.  This group also had the
>VP of Engineering's ear and blessing.

As I heard it, it ain't as clean as that:

C. Gordon Bell was technical god at DEC just then.  He could do no wrong
and had KO's ear for any purpose.  Bell was into writing books at that time,
and "Digital Press" was created as the outlet for his work, etc.  Bell had
designed a register-description notation as part of a book he was working
on.  It is a separate matter as to whether this notation is useful for
describing machine architecture, but the relevant point is that *he*
thought so.

Apparently, two young relative newbies in DEC engineering read his work and
used it to toy around with a new machine design (which eventually became the
-11).  Their work is not fully polished, and suffers from some inconsistencies.
(Such as the condition codes aren't exactly the same as a result of an
increment or decrement as opposed to adding or subtracting 1, or that
byte forms of instructions don't quite set the same results as the word forms
of the same instructions.  The point is that a carefully planned work of
architecture design would have located these shortcomings and corrected them.
Much has been published about these issues elsewhere, etc.)

It apparently came down to the fact that the "green light" had been given
for the NOVA project, and sub-design teams formed, etc.  Note that one of
the design goals for this project was to use larger boards to overcome the
limitations of FLIP-CHIP modules which can't have much functionality per
card because of lack of fingers.  Back in the negative logic days, a
one-sided card with 18 fingers was generally adequate because you could only
put so much discrete logic on a module.  But de Castro realized that with the
advent of TTL, merely making the cards double-sided wouldn't be enough.  His
idea has been vindicated since the next few DEC machines all suffer from the
same problem: lots of little cards with mostly empty space on them.  Using
only two or three chips uses up all of the fingers, so you shortchange TTL's
ability to downsize the design and only achieve 2-3 times the shrinking as
compared to discrete negative logic using the same size cards with 36 fingers
total.  By using much larger cards, the chips interconnect, not the modules.
Thus, the larger cards usefully are constructed from a decent number of TTL
packages, and only a buss approach goes off the cards onto a goodly number
of fingers.  This eliminates a lot of wire-wrap and opens the possibility
of making a pc-board buss such as the later OMNIBUS of the PDP-8/e.

>
>It came to a contest between the two architectures to produce what would be
>the PDP-11.  de Castro's group lost, and the PDP-11 became the two-operand
>architecture we know and love.  de Castro resigned immediately to set up
>Data General.  The first computer was the Nova, the architecture of which 
>looked *suspiciously* like that of the 16 bit computer he developed at
>DEC.....  The Nova became the Eclipse and then the 32 bit Eclipse MV series
>in response to the release of the VAX 11/780 by DEC in 1977.  The story is
>taken up in detail from 1977 by Tracy Kidder's book.

Bell's ego was stroked by the hasty work of the two newbies.  He pulled all
the strings he was capable of, including telling KO to pull the plug on the
NOVA project because this was so much better than it wasn't worth persuing
it anymore, even though hundreds of people were committed to it, etc.  As
a result of this politicizing, the -11 design was pushed through hurriedly,
and didn't stop for any analysis of the design for holes, etc., so it was
produced, horns and all, as originally specified, and onto a typical
inefficient design with lots of little cards as the 11/20.  (Admittedly some
of the modules were a little bigger than the typical small M-series module,
but then again this size also exists on certain PDP-8 peripherals as the
"double-height" card in R-series, etc.)  In fact, some of the mechanical
parts of the 11/20 are identical to the 8/l and 8/e, proving that the
details of the project were expediently handled, instead of doing a
complete ground-up design as in the past.

>
>As to whether the pdp11 succeeded soley because the VP liked the guy 
>behind it, we'll never really know.

That depends on the veracity of the story.  Human nature being what it is,
it is likely that some of the way it was retold to me is exaggerated.  What
is true, is that de Castro and 200 or so people quit DEC simultaneously and
quickly formed DG and produced NOVAs from then onward.

>  However, the architecture *is* nice;
>I'd say it has a lot less warts than the PDP-8 or PDP-10, given that it 
>is a 16 bit minicomputer architecture.

Your opinion isn't a given, although I really don't want to open the topic
about the -11 versus the -8 and company.  However, it is sufficient to say
that there are debatable issues about 16 bit machines in general, byte
versus word addressing, and specifics regarding inconsistencies in the -11
design specifically, and whether or not a lot of its popularity stems from
the usefullness of the software as opposed to the underlying architecture.
(There are many people enamoured of RT-11, not the -11 per se.  In fact, they
want RT-32 or RT-64 for their favorite 32 or 64 bit designs, not -11
compatibility at all.)  Moreover, it is clear that DEC imposed the -11 into
some situations where clearly the -8 was more than adequate.  In one infamous
example, DG underbid DEC in selling a large number of systems to Disney because
the NOVA systems were cheaper than DEC's -11-based offerings, and clearly the
-8 could have brought in a more competitive system for the project.  (From
what I understand about the requirement, a modern version of this project
would specify something akin to hundreds of 8051-class 8-bit controller micros,
but they didn't exist back then.)

>  Competition is basically the way
>development is done within DEC -- products fly or die on their merits (or
>by favourably impressing an appropriate VP).  People do resign over these
>decisions; de Castro's case is only remarkable because he went and set up
>a reasonably successful company in quite direct competition with DEC.

True, but not useful; it's one of DEC's long-term major shortcomings that
each project attempts to get funded by backstabbing everything else, and
attempting snow jobs on technically incompetent upper management types.  A
notable example: the VAXmate, which was undeliverable for over two years, yet
caused the cancellation of other viable projects while it stalled and 
eventually burned.

>
>Kidder does avoid the question of de Castro's departure, but he does
>allude to some of the conflicts between DG and other parts of the computer 
>industry, especially DEC.  

It would be interesting to expand on these issues.  Maybe DEC will not
repeat their mistaken patterns of the past.

>
>
>--
>Don Stokes, ZL2TNM (DS555)                        [email-masked] (home)
>Network Manager, Computing Services Centre            [email-masked] (work)
>Victoria University of Wellington, New Zealand              +64-4-495-5052

cjl

---

From: [email-masked] (Don Stokes)
Date: 7 Dec 92 11:02:56 GMT

> Edson de Castro was Chief Engineer of the original negative logic PDP-8.  He
[...]
> C. Gordon Bell was technical god at DEC just then.  He could do no wrong
[...]
> NOVA project because this was so much better than it wasn't worth persuing

That basically gels with my rather wooly recollection.

> quickly formed DG and produced NOVAs from then onward.

One thing DEC always has been pretty good at is keeping its politics 
behind its doors; only when something genuinely visible happens (eg de
Castro's departure, Jupiter's cancellation) does the brown stuff fly
outside.

> about the -11 versus the -8 and company.  However, it is sufficient to say

Well, I do, since I'm a nit more in my depth... 8-)

> the usefullness of the software as opposed to the underlying architecture.

There are a lot of people who would put their hands on their hearts and say
the -11 architecture is the nicest they've used.  I'd be one of them.  
Personally, I feel the pdp11 instruction set has fewer warts on it than the
VAX set in terms of overall consistency (if you ignore the FIS & CIS sets 
which were bags added to the side of the arhitecure later on).  Bell's 
"golden boys" did a surprisingly good job, even if it was a bit rushed.

The pdp11 also marked a noticable change in direction for instruction set
architecures; up to then, all DEC machines had been word oriented and
single word instructions.  This development led on to the VAX architecture,
which took multiple part instructions rather to extremes.  

Basically, DEC had gone for instructions that looked like:

	+--------+--------------------+
	| opcode |      operand       |
	+--------+--------------------+

Now they were splitting the operand from the opcode:

	+-----------------------------+
	|           opcode            |
	+-----------------------------+
	|           operand           |
	+-----------------------------+
	|           operand           |
	+-----------------------------+

They also did away with special registers and other warts on the
architecture required when all the information about an instruction,
*including* literals, was crammed into one word.  Allowing for separate
literals also means that you don't need to do segmentation to get a 
decent address space, which was a problem on all previous machines.

It's interesting to note that many of the techniques used in the word-
oriented machines are re-introduced in today's RISCs.  However, there are
differences:

	- RISCs generally do not use special registers for actions such
	  as auto-increment.
	- RISCs usually have full-sized addressing once addresses are 
	  fetched into registers.  On early DEC computers, the size of the
	  operand literal field was also the limit of the virtual address
	  space.
	- Many RISCs still use byte-oriented addressing.
	- On early DEC machines, the word orientation was to simplify the
	  instruction decode; on RISCs the fixed instruction sizes are to
	  keep the pipeline filling at a constant rate.

Basically, the fact that the architectures "converged" again is largely
co-incidence -- the reasons for doing it that way were very different in
the 1960s to the reasons of the late 80s.  It's hard to say if the movement
of architectures towards multiple word multiple operand instruction sets
throughout the 70s was spearheaded by the pdp11, or whether the pdp11 just
rode the wave of development that culminated in the VAX.

> want RT-32 or RT-64 for their favorite 32 or 64 bit designs, not -11

There was always a cry for an "RT32" when the VAX came out as the pdp11's
"successor".  DEC almost supplied it in VAXeln, but it had the snag that
development had to be done on a host (usually) VAX/VMS system; you could
develop under VMS and reboot into VAXeln, but this proved unworkable for
most developers, who either splashed out on an extra VAX, or (more often)
stuck with their RSX or RT11 systems where they could both write and test
their systems on the same box.  The VAX never  did "hard" realtime as well
as the pdp11 either, largely because of the  somewhat more baroque
interrupt handling.

> some situations where clearly the -8 was more than adequate.  In one infamous

DEC are good at that; as are others.  Let's face it, DEC always pushed 
their latest snaziest boxes -- put yourself in the place of the salesdroid;
would you say:

	"Here it is, it's been around for a while, it'll do the job."
or
	"Here's our latest hot box!"

(Remember, this is a salesdroid!)

I suspect many "DEC blunders" have been just cases of the salesthing not
quite reading the territory and getting it wrong.  

> caused the cancellation of other viable projects while it stalled and 

Whether the technique works or not depends a lot on the personalities; but
I'd challenge you to demostrate any R&D management technique that doesn't
have shortcomings, particularly that one.  A project may get killed, but
often  the deveoplement work is put into practice eventually.  For example,
DEC actually had a RISC architecture going before they decided to go to
MIPS chips; that work was not lost, but found its way into Alpha.

> repeat their mistaken patterns of the past.

I haven't followed DG much, but I often got the feeling they were soley 
after DEC's market, sort of like a small yappy dog (the kind you just want
to step on) going for their heels, and largely leaving everyone else alone.

It's a fairly common theme in Kidder that Eagle is soley an attempt to go
after the VAX; the development is reactive rather than proactive.

---

From: [email-masked] (CP/M lives!)
Date: 7 Dec 92 10:25:34 MDT

In article <[email-masked]>, [email-masked] (Don Stokes) writes:
>   For example,

A joke that I heard at a DEC site was that AXP stands for Almost eXactly Prism.
-- 

Roger Ivie                      "My God! That computer is full of Pentium!
[email-masked]                  It's a wonder that you haven't been turned
                                 into mutants!"

---

From: [email-masked] (Steve Holzworth)
Date: Mon, 7 Dec 1992 19:56:55 GMT

>[email-masked] (Charles Lasner) writes:

 stuff deleted

>Castro's departure, Jupiter's cancellation) does the brown stuff fly

stuff deleted

To further complicate things: I was told once that there used to be yet
a THIRD group within DEC working on the "future PDP" who also lost out,
and spun off into a company called GRI. They made a system called the GRIP.

The only reason I heard this was that I used to work for a company that 
was involved in a triple merger, one component of which was GRI. It was 
mostly in decline, and was eventually shut down by the new parent company
(Fulcrum Computer Group). Fulcrum was eventually sold to Adage, Inc., 
whose main goal was to acquire the Ikonas Graphics Systems component thereof
(Ikonas was a high-end graphics hardware vendor in the late 70s, early 80s;
sort of that era's Silicon Graphics...). 

Anecdote:
Adage was a graphics vendor from the early/mid seventies. They had vector 
graphics with hardware transformations. The machine was also ONE'S COMPLEMENT 
math. Those negative zeros are a pain :-).

>to step on) going for their heels, and largely leaving everyone else alone.

Several people here used to work at DG in Research Triangle Park. They
actually had lots of innovative hardware in development. Invariably, the
idiots in the front office wouldn't understand the signifigance of the
advance and would shut down the effort before it hit the market.

--
Steve Holzworth
[email-masked]                         "Do not attribute to poor spelling
x6872                                    That which is actually poor typing..."
SAS Institute - Open Systems R & D                      - me
Cary, N.C.

---

From: [email-masked] (51351[efw]-Robert Feddeler(MT4799)T343)
Date: Mon, 7 Dec 1992 22:20:47 GMT

>increment or decrement as opposed to adding or subtracting 1, or that
 ^^^^^^^^^^^^^^^^^^^^^^
>Much has been published about these issues elsewhere, etc.)

There is actually more thought invested in the 11's instruction set than
meets the eye.  The reason 'inc' and 'dec' don't modify the Carry bit
is to allow for inc's and dec's on loop counters in multi-word arithmetic
routines that need to propogate the C-bit and shouldn't have to waste time
saving and restoring it.  After an add #1, or sub #1, the C- and Z-bits
are always the same.  BNE is equivalent to BCC after an increment or
decrement.

This "feature" caused me a bit of pain at a little after 18:00 hours one
day back in 1975 in the basement of the "mill".  My check for overflow
after an inc on the low order word of the "seconds since midnite" counter
was a BCC that would _always_ branch.

Noto Bne!

bob.			| Heap big trouble in the land of plenty.
Were these more than just my opinions, they would have cost a bit more.

---

From: [email-masked] (John R. Levine)
Date: Sun, 13 Dec 1992 19:09:31 GMT

[email-masked] (Charles Lasner) writes:
>card because of lack of fingers.  ...

Actually, there was a sensible reason that DEC used small cards.  The
PDP-6 (the machine that the PDP-10 was almost as good as) used great big
cards with lots of pins per connector.  Unfortunately, the connectors
didn't work very well.  A standard diagnostic technique when a PDP-6 was
flaking was to open the back and hit all the modules with a rubber mallet.
For that among other reasons the PDP-6 was a marketing failure and they
only built 20 of them.

The later KA10, the first PDP-10, used small Flip-Chip modules the same
size as the ones used in the wildly successful original PDP-8.  (The -10
was mostly B series modules, which were faster than the R and S series
used in the PDP-8.)  It wasn't until the PDP-11/45 that DEC found large
connectors in which they had confidence, and even then, the 11/45's cards
had little latches that you used to force the connectors very firmly into
their sockets.

As far as the Nova ripping off DEC goes, I have a copy of ``How to use the
Nova and the Supernova,'' the programmer's manual for DG's first two
machines, dated 1970.  The design and typography are exactly the same as
in the DEC PDP-10 manual.  It was written by William English, who wrote
the PDP-10 manual.  On page 2-44, when discussing the memory protection
feature, it says ``In particular, do not execute a JSR into a protected
page,'' a piece of advice that also appears almost verbatim in the PDP-10
manual.  But the Nova's JSR saved its return address in a register,
causing no problem when jumping into a read-only segment, while the
PDP-10's JSR stored the return address at the jumped-to location, which
doesn't work in read-only memory.  Oops.  Wrong computer.

-- 
John R. Levine, IECC, POB 349, Cambridge MA 02238, +1 617 492 3869
[email-masked], {ima|spdcc|world}!iecc!johnl
"Time is Money!  Steal some today!"

---

From: [email-masked] (Douglas W. Jones,201H MLH,3193350740,3193382879)
Date: Sun, 13 Dec 1992 21:05:42 GMT

>From article <[email-masked]>,
> flaking was to open the back and hit all the modules with a rubber mallet.

The PDP-11/20 may have been made with small cards, but this didn't fix
the problem.  We had an 11/20 at the University of Illinois, and as it
aged, cards began to get loose, and the common fix was to gently kick
the underside of the machine to reseat the cards.  On failure, you'd
kick it and reboot, and only if that failed was it worth trying anything
more impressive.  Kicking seemed to work about 90% of the time.

The machine was rack-mounted, but there was nothing under the CPU, and
the blank panels had long since been removed from that space by 1973
when this story takes place.

To understand why it worked, you have to know that the PDP-11/20 was
mounted with the wire-wrapped backplane on top and the cards pushed in
from the bottom.  The mounting slides were tiltable, so you could pull
the box out of the rack and tilt it up to face the boards towards you,
or tilt it down to face the backplane towards you.

The boards were retained in their slots by the foam lining on the inside
of the bottom cover of the CPU.  This foam was stiff grey stuff, a type
still commonly used for padding electronics.  The problem is, the stuff
ages, particularly in a warm environment, and as it ages, it looses its
spring and becomes mushy.  The CPU was in a high noise environment
(a card reader and line printer were right there), and I gather that the
vibrarion was enough to work cards loose after the foam lost its spring.

				Doug Jones
				[email-masked]

---

From: [email-masked] (Jeff DelPapa)
Date: Mon, 14 Dec 1992 00:38:48 GMT

>For that among other reasons the PDP-6 was a marketing failure and they

One peice of (likely) apocrapha regarding the nova board size...  It
seems that a number of people at dec had pdp-8's in their basement
built in the same mode as the Cadillac in that old country standard
"one peice at a time".  DG as cost conscious as it ever was,
supposedly designed Nova boards such that they wouldn't fit in
breifcases, printouts, or under the coat (no matter how fat the wearer
of the coat).

the following are supposedly not apocrapha:

DG didn't want cloned memory boards, and had one trace on their memory
board that had an inconspicious break - the sort that someone trying
to copy the board would assume was a bad spot on the copy and fix -
this would connect the +12 supply line to the core stacks sense wire -
powering up such a board would let all of the magic smoke out of the
core stack.

On the nova 1200's, there was a power supply crowbar module. It was
potted, they were assembled by a single technician, and no prints of
the thing were available.  This module was also the source of some of
the timing signals. It was a $500 part from field service. I saw one
that the potting had been carefully removed from - it contained 6
chips. (numbers were removed, possibly by the removal of the potting,
so I cannot give an accurate actual cost estimate)

The novas had power fail restart as a $250 option. It was implemented
(on the 1200 anyway) by two chips (a comparator and a latch I think,
tho it may have been a one-shot and a gate) on one of the CPU cards.
By default the chips were installed on all boards manufactured, and
diked out if not ordered.  The going rate for a bootleg installation
from the field service techs was $50 (the chips cost about $0.45).

<dp>

---

From: [email-masked] (Charles Lasner)
Date: Mon, 14 Dec 1992 09:05:19 GMT

>For that among other reasons the PDP-6 was a marketing failure and they

Two things:

First of all, those big connectors don't really have more pins, they have
bigger pins, and they're gold-plated, but because they are short, they can
be flakey, especially with a massive card on the other end of the connector,
so it's a matter of bad choice of connector mechanism, not quantity of
connections.  Also, the PDP-6 and KA-10 era doesn't have the problems I'm
talking about, namely when TTL came into vogue.  Now you had too much logic
and not enough local interconnect if the only way to interconnect was at
a module level with only 36 pins total.  So, bigger cards allows for more
pins to interconnect with, and encourages local chip interconnections that
are not brought out to the connector at all.

Second, I heard they made 20 PDP-6's, yet someone else insists 23.

>had little latches that you used to force the connectors very firmly into

Wrong, the Omnibus predates the 11/45, and uses multiple connectors of the
small variety on a big card.  The hex boards were used in those -11's and
then the 8/a.  I'm not sure if hex boards predate Q-bus, but in any case the
Omnibus is older than both of them, and was being developed at about the
same time as the UNIBUS itself, although not made out of hex boards back then.

[good stuff deleted]

Since they had the "style" of the 36-bits, and the "guts" of the 12-bits,
DG was a "generic" DEC rip-off.  In any case, that's what happens when you
pull the plug of a carefully planned project over a hastily formed weekend.

cjl

---

From: [email-masked] (Sarr J. Blumson)
Date: 14 Dec 1992 14:24:29 GMT

>For that among other reasons the PDP-6 was a marketing failure and they
Some of this, of course, was due to DEC's fondness for using vertical
backplanes where the connector was the _only_ mechanical support the
cards had.  I once watched some slighly inebriated movers run a KA-10
up a ramp a little too hard; some of the noards just popped out.  Of
course after we put them back in it worked fine.

(Sarr Blumson)

---

From: [email-masked]
Date: Wed, 16 Dec 1992 12:31:24 GMT

> For that among other reasons the PDP-6 was a marketing failure and they

Bzzzt. You are thinking of the CDC6x00 and Cybers. The prob with the 6's cards
was that they where SOLDERED in, some on BOTH sides...

~Paul

---

From: [email-masked] (Tyzuk William N)
Date: Fri, 18 Dec 1992 21:22:58 GMT

>was that they where SOLDERED in, some on BOTH sides...

Lessee now... I think it was a CDC1700 mini that had a 256k word (??)
drum (actually a disk but they called it a drum) which came with a plastic
hammer and maintenance manual which prescribed tapping the cards with
the hammer to cure intermittant faults!  This was an actual recommended and
authorized maintenance procedure!  Sigh.... the good ol' days :-)  NOT.

---

From: [email-masked] (Seth "the Lesser")
Date: Fri, 18 Dec 1992 22:35:34 GMT

>authorized maintenance procedure!  Sigh.... the good ol' days :-)  NOT.

Good ol' days my bleeding arse.  We have a pack of Sun SPARCstations here at
CTR with cut-rate hard drives that freeze up whenever we power down.  The best
way to unfreeze them (saith my boss, and I've seen him do it with excellent
results) is to tap them with a hammer.  Lightly, of course.

Seth L. Blumberg          \ Warning: This posting has been determined to cause
[email-masked] (play)   \ cancer in laboratory animals.  Please make sure
[email-masked] (work) \ that no white mice are allowed to read it.  
    > No one I know shares my opinions, least of all Columbia University. <

---

From: [email-masked] (Thayne Forbes)
Date: 20 Dec 92 00:05:58 GMT

Seth the Lesser ([email-masked]) wrote:
: [email-masked] (Tyzuk William N) writes:
: >
: >Lessee now... I think it was a CDC1700 mini that had a 256k word (??)
: >drum (actually a disk but they called it a drum) which came with a plastic
: >hammer and maintenance manual which prescribed tapping the cards with
: >the hammer to cure intermittant faults!  This was an actual recommended and
: >authorized maintenance procedure!  Sigh.... the good ol' days :-)  NOT.
: 
: Good ol' days my bleeding arse.  We have a pack of Sun SPARCstations here at
: CTR with cut-rate hard drives that freeze up whenever we power down.  The best
: way to unfreeze them (saith my boss, and I've seen him do it with excellent
: results) is to tap them with a hammer.  Lightly, of course.
: 
This time honored maintenance technique was in real danger of becoming a 
lost art a few years ago, but Apple came to our rescue and rejuvinated it
with the introduction of Quantum 40 (and I think Quantum 80) drives, which
regularly refused to spin up after cold boot.  At the time we (Unisys) were
about to use the same drives in a $1 Billion PC contract, and I can tell you
we didn't know whether to snicker about Apple, or sweat bullets because
we couldn't figure out why they worked so well for us.  Turns out to have
been an electrical problem (which some electrically literate Mac user will
have to explain) which we didn't suffer from because of our monster power
supplies.  We did suffer a few very nervous days investigating tho.
-- 
Thayne Forbes
[email-masked]