TPUG - Toronto PET Users Group/TPUG Users Group CD/TPUG Users Group CD.iso/CRS/crs49.d81/histry.cbm

Text File | 2009-10-10 | 24KB | 417 lines

The following series of messages were posted by former CBM design engineer
Bil Herd 71155,533.  They represent a fascinating look into the "behind the
scenes" shenanigans at Commodore while the C128 was being produced.  Enjoy!

This file will be updated periodically as Bil gives us more of the story.

                             --*--*--*--*--*--


03-Jan-93  00:09:52

Ya interested in history??? Ever hear of the Chuck Peddal Special pin ?  If
you pull out the ORIGINAL (HANDRAWN!) schematics of tthe 6502 there is an
unusual pad marked CPS. This later went on to be the Set Overflow (SO) pin of
renowned 1541 use.

VIC modes of operation are actually fairly well documented in places like the
C64 and C128 programmers reference guide.  Do you mean memory maps or VIC
Modes of operation like the Famous
Multi-Color-Character-Except-every-fourth-Thursday mode?  (I.E. those
semi-silly modes that give the VIC chip its versatilty).  There arn't really
any unsupported modes as if there was a hidden mode, meaning one the
designers didn't know about, it was usually exploited by the ingenious crowd
of developers.

Bil

P.S. Have you come across any mention of the 8510-HERD?  Special run chip (48
pin) that was like gold to developers during C128 development.



12-Jan-93  19:28:05

Coming soon to a terminal near you... the gruesome story of the chip that
almost ruined CES (and the C128 along with it)

EXPERIENCE the shame and horror of being a Chip Designer at Commodore during
the Witch hunts!

SEE the expresions on Managers faces when they realize that their Bonuses are
at stake!

HEAR the woeful lamenting of the programers as they are beaten for no
apparent reason!

SHARE the experience of being a Hardware Engineer... stalking the halls in
search of programmers to beat (for no apparent reason).

LEARN how to say "THIS CHIP ONE SICK PUP" in Japanese.

Find out just how badly busted up the 80 column chip was and how many DIRTY
fixes were needed to make that all crucial show in Vegas on January 6.
(Christmas, what Christmas). .

<Said rather coyly in an attempt to elicit any positive responses> Unless of
course no one is interested..... :) Bil


14-Jan-93  15:37:59

This is the first of many parts as this thing went round and round during our
mad dash to make the CES show. I don't even remember what year it was. The
8563 was a holdover from the Z8000 based C900 (the "Z" machine as we called
it). The people who worked on it were called the "Z" people, the place they
hung out was called the "Z" lounge and well.... you get the idea.

The most interesting thing that came out of that group besides a disk
controller that prompted you for what sector and cylinder you'd like to write
to on every access, was one day they stole the furniture out of the lobby and
made their own lounge disguising it as a VAX repair depot. We were so
amused by this that we stopped teasing them for a week.  (But I become
distracted....)

Now the very very very early concept of the C128 was based on the D128, a
6509 based creature (boo... hiss).  The engineers on the project had tacked a
VIC chip onto the otherwise monchrome (6845 based) in an effort to add some
color to an otherwise drab machine. No one dreamed that C64 compatibility was
possible so no one thought along those lines. I was just coming off of
finishing the PLUS 4 (before they added that AWFUL built in software to it)
and even though I had done exactly what I was told to do I was not happy with
the end result and had decided to make the next machine compatible with
_something_ instead of yet another incompatible CBM machine. (I won't go into
the "yes Virginia there is Compatibility" memo that I wrote that had the
lawyers many years later still chuckling, suffice it to say I made some
fairly brash statements regarding my opinion of product strategy)
Consequently, I was allowed/forced to put my money where my mouth was and I
took over the C128 project.

I looked at the existing schematics once and then started with a new design
based on C64ness. The manager of the chip group approached me and said they
had a color version of the 6845 if I was interested in using it it would
deffinately be done in time having been worked on already for a year and a
half...... And so the story begins..... (to be continued)


16-Jan-93  19:06:28

Looking back I realize that the source of a lot of the problems with the 8563
is that it wasn't designed FOR the C128 and that the IC designers did not
take part in the application of their chip the way the other designers did.
The VIC and MMU designers took an active interest in how their chip was used
and how the system design worked in relation to their chip. I overlooked
ramifications of how the 8563 was spec'ed to work that came back to haunt me
later. For example, it was explained to me how there was this block transfer
feature for transferring characters for things like scrolling.  Cool.... we
need that. Later it would turn out when this feature finally did work
correctly that it only was good for 256 characters at a time. 256 characters
at a time. 256 characters at a time?? I never stopped to think to ask if the
feature was semi-useless because it could only block move 3 and 1/3 lines at
a time. Did I mention the block move was only good for 256 characters.  Later
a bug in this feature would almost prove a show stopper with a serious
problem showing up in Vegas the night of setup before the CES show. But I get
ahead of myself. It was also my understanding that this part had the same
operating parameters as the 6845, a VERY common graphics adapter.  Not
scrutinizing the chip for timing differences the way I normally did any new
chip was another mistake I made.  The major timings indicated what speed
class it was in and I didn't check them all. I blame myself as this really is
the type of mistake an amateur makes.  I wonder if I was in a hurry that day.
:)


16-Jan-93  19:06:39

It turns out that a major change had been made to the way the Read/Write line
was handled. When I asked about this, VERY late in the design cycle, like in
Production when this problem turned up, I was told "remember,, this was
designed to work in the Z8000 machine." ???!!!! ????!!!! Shoulda seen the
look on my face! Even though the Z8000 machine was long dead and we had been
TRYING for 6 months to use this damm thing in the C128 I'm being told NOW
that you didn't design it to work the way we've been using it for 6 months?
Shoulda asked.... it was my fault, shoulda asked "is this meant to work".....
:/

Looking back I realize that the source of a lot of the problems with the 8563
is that it wasn't designed FOR the C128 and that the IC designers did not
take part in the application of their chip the way the other designers did.
The VIC and MMU designers took an active interest in how their chip was used
and how the system design worked in relation to their chip. I overlooked
ramifications of how the 8563 was spec'ed to work that came back to haunt me
later.  For example, it was explained to me how there was this block transfer
feature for transferring characters for things like scrolling. Cool.... we
need that. Later it would turn out when this feature finally did work
correctly that it only was good for 256 characters at a time. 256 characters
at a time. 256 characters at a time?? I never stopped to think to ask if the
feature was semi-useless because it could only block move 3 and 1/3 lines at
a time. Did I mention the block move was only good for 256 characters.  Later
a bug in this feature would almost prove a show stopper with a serious
problem showing up in Vegas the night of setup before the CES show. But I get
ahead of myself.


16-Jan-93  19:06:50

It was also my understanding that this part had the same operating parameters
as the 6845, a VERY common graphics adapter. Not scrutinizing the chip for
timing differences the way I normally did any new chip was another mistake I
made.  The major timings indicated what speed class it was in and I didn't
check them all. I blame myself as this really is the type of mistake an
amateur makes.  I wonder if I was in a hurry that day. :) It turns out that a
major change had been made to the way the Read/Write line was handled.  When
I asked about this, VERY late in the design cycle, like in Production when
this problem turned up, I was told "remember,, this was designed to work in
the Z8000 machine." ???!!!! ????!!!! Shoulda seen the look on my face!
Even though the Z8000 machine was long dead and we had been TRYING for 6
months to use this damm thing in the C128 I'm being told NOW that you didn't
design it to work the way we've been using it for 6 months? Shoulda asked....
it was my fault, shoulda asked "is this meant to work the way were using it?"
:/

Don't get me wrong, the designer was VERY bright, he held patents for some of
the "cells" in the Motorla 68000. It just that chip had to work in
conjunction with other chips and thats where some ofd the problems lay.  Our
story opens as Rev 0 of the chip.... (whats that..... doesn't work.... OK,)
Our story opens as Rev 1 of the chip makes its debut and ......(pardon me a
moment.....) Our story opens as Rev 2 of the chip makes it debut..... <to be
continued>


19-Jan-93  20:50:41

Forgive the sporadic nature of these additions.  Now where was I .... oh
yeah.... It was sometime in September when we got 8563 Silicon (or so memory
serves) good enough to stick in a system. I can't remember what all was wrong
with the Chip but one concern we had was it occasionally (no spell checker
tonight, bear with me) blew up.... big time.... turn over die and then smell
bad..... But then all of the C128 prototypes did that on a semi regular basis
as there wasn't really any custom silicon yet, just big circuit boards
plugged in where custom chips would later go... but you can't wait for a
system to be completed before starting software development.   I don't think
any of the Animals really gave it a thought until when the next rev of the
chip came out and now with less other problems the blowing up 'seemed' more
pronounced.  Also the protoypes got more solid _almost_ every day.  (I knew
to go check on the programer's prototype whenever I heard the sound of cold
spray coming out of their office.... later it turned out they usually weren't
spraying the boards just using their "Hardware Engineer" call.  Sometimes all
I had to do was touch the board in a mystical way and then back out slowly
sometimes accompanied by ritual like chanting and humming.  This became know
as the "laying of hands".  This worked every time execpt one, and that time
it turned out I had stolen the power supply myself without telling them....
If anybody else got caught "messing with my guys" they'd get duct taped to a
locker and then the box kicked out from under them leaving them stuck until
they could peel themselves down, but thats another story.)  ANYWAY, when this
problem still existed on Rev 4 (I think it was) we got concerned.  It was at
this time that the single most scariest statement came out of the IC Design
section in charge of the '63.  This statement amounted to "you'll always have
some chance statistically that any read or write cycle will fail due to
(synchronicity)".


19-Jan-93  21:12:05

Synchronicity problems occur when two devices run off of two separate clocks,
the VIC chip hence the rest of the system, runs off of a 14.318Mhz crystal
and the 8563 runs off of a 16Mhz Oscillator. Now picture walking towrds a
revolving door with your arms full of packages and not looking up before
launching yourself into the doorway. You may get through unscathed if your
timing was accidentally just right, or you may fumble through losing some
packages (synonymous to losing Data) in the process or if things REALLY foul
up some of the packages may make it through and you're left stranded on the
other side of the door (synonymous to a completely blown write cycle). What I
didn't realize that he meant was that since theres always a chance for a bad
cycle to slip through, he didn't take even the most rudimentary protection
against bad synchronising. IT's MY FAULT I didn't ask, "what do you mean
fully by that statement" because I'd of found out early that there was NO
protection. As it turns out the 8563 instead of failing every 3 years or so
(VERY livable by Commodore standards) it failed about 3 times a second.  In
other words if you tried to load the font all in one shot it would blow up
every time!  The IC designers refused to believe this up until mid December
(CES in 2-3 weeks!) because "their unit in the lab didn't do it."  Finally I
said "show us" and they led the whole rabble (pitch forks, torches, ugly
scene) down to the lab.  It turns out they wern't EVEN TESTING THE CURRENT
REV of the chip, (TWO revs old), they were testing it from Basic because it
"blew up" every time they ran it at system speeds (No %^$#%$# sherlock.
That's what we're trying to tell you) and even then it screwed up once and
the designer reached for the reset switch saying that something does
occasionally go wrong.  Being one of the Animals with my reflexes highly
tuned by Programer Abusing I was able to snatch his arm in mid-air before he
got to the reset switch, with blatant evidence there on the test screen.


19-Jan-93  21:12:15

One of the rabble was their boss and (I have been speaking about two
designers interchangeably, but then they were interchangeable,) the word
Finally came down "FIX IT".  Hollow Victory as there was only two weeks till
we packed for the show, and there were 4 or 5 other major problems (I'll say
more later) with the chip and NO time to do another pass. It was obvious that
if we were going to make CES something had to give. As Josey Wales said,
"Thats when ya gotta get Mean.... I mean downright plumb crazy Loco Mean".
And we knew we had to.


22-Jan-93  14:17:32

Memory flash, I just remebered when we found out there was no interrupt
facility built in to the 8563.  I remember how patient the designer was when
he sat me down to explain to me that you don't need an interrupt from the
8563 indicating that an operation is complete because you can check the
status ANY TIME mearly by stopping what you're doing (over and over) and
looking at the appropriate register, (even if this means banking in I/O) or
better yet sit in a loop watching watching the register that indicates when
an operation is done (what else could be going on in the system besides
talking to the 8563 ???)  Our running gag became not needing a ringer on the
phone because you can pick it up ANY TIME and check to see if someone's on
it, or better yet, sit at your desk all day picking the phone up.   Even in
the hottest discussions someone would suddenly stop, excuse himself, and pick
up the nearest phone just to see if there was someone on it.  This utterly
failed to get the point across but provided hours of amusement.  The owners
at the local bar wondered what fixation the guys from Commodore had with the
pay phone.

Any ways.... To back up to the other problems that plauged the 8563.  Going
into December a couple of things happened.  The design had been changed to
support a "back-bias generator".  This thing is generally used to reduce
power consumption and speed the chip up.  Well, something was not quite right
somewhere in the design because the chip got worse.  The second thing that
happened was that both designers took vacation.  Nothing against that from my
point of view here 8-9 years in the future, but right then we couldn't
understand what these people were doing working on a critical project.


22-Jan-93  14:17:37

Or maybe I was just getting to used to eating Thanksgiving Dinner out of
aluminum foil off of a Lab Bench.  Christmas consisted of stopping at
someone's house who lived in the area for a couple of hours on the way home
from work.  Anyways, the chips could no longer display a solid screen.  The
first couple of characters on each line were either missing or tearing, until
the thing heated up, then they were just missing.  Also, the yield of chips
that even worked this good fell to where they only got 3 or 4 working chips
the last run.  A run is a Half-Lot at MOS and costs between $40,000 and
$120,000 to run.  Pretty expensive couple of chips.

The other problem takes a second to explain, but first a story.....  Back
when TED (the Plus four) had been mutilated decimated and defecated upon,
managment decided to kick the body one last time.  "TED shall Talk" came the
decree and the best minds in the industry were sought... We actually did have
two of the most noted consumer speech people at the time, the guys who
designed the "TI Speak an Spell" worked out of the Commodore Dallas office.
They did a custom chip to interface a speech chip set to the processor.
Operating open loop, in other words without feedback from any of the system
design people (US) they defined the command registers.  There was a register
that you wrote to to request a transfere.  To REALLY request the transfer you
wrote the same value a second time. We refered to this as the "do it, do it
now" register or the "come on pretty please" request, or my favorite, "those
#$%&@ Texans" register. ANYWAYS, the 8563 also had a problem where the 256
'bite' transfer didn't always take place properly, leaving a character
behind. This ended up having the effect of characters scrolling upwards
randomly.


22-Jan-93  14:17:45

So to recap, going into December we had a chip with .001% yield, the left
columns didn't work, anytime there was one pixel by itself you couldn't see
it, the semi useless block transfer didn't work right, the power supply had
to be adjusted for each chip, and it blew up before you loaded all of the
fonts unless you took 10 seconds to load the fonts in which case it blew up
only sometimes. Finger pointing was in High swing, (the systems guys should
have said they wanted WORKING silicon) with one department pitted against the
other, which was sad because the other hardworking chip designers had
preformed small miracles in getting their stuff done on time. Managers
started getting that look rabbits get in the headlights of onrushing Mack
trucks,  some started drinking, some reading poetry aloud and the worst were
commonly seen doing both. Our favorite behaviour was where they hid in their
offices.  It was rumored that the potted plant in the lobby was in line for
one of the key middle managment positions. Programmer beatings had hit a new
high only to fall off to almost nothing overnight as even this no longer
quelled the growing tension. A sprinkler head busted and rained all over
computer equipment stored in the hallway. Engineering gathered as a whole and
watched on as a $100,000 worth of equipment became waterlogged, their
expressions much like the bystanders at a grisly accident who can't tear
their attention away from the ensuing carnage.  I can honestly say that it
didn't seriously occur to me that we wouldn't be ready for CES, for if it
had, I might have succumbed to the temptation to go hide in my office
(checking the telephone).  There were just too many problems to stop and
think what if.  Next time (hopefully) I'll try and bring all the problems and
answers together and explain why I stopped to tell that rather out of place
TED story.


30-Jan-93  19:27:11

No single custom chip was working completely as we went into December with
the possible exception of the 8510 CPU.  The MMU had a problem where data was
"bleeding through" from the upper 64K bank into the lower.  This was in part
due to a mixup in the different revision of "layers" that are used to make
chips. This chip essentially had one of the older layers magically appear
bring old problems with it.  Unfortunately, this older layer had been used to
fix newer problems so we didn't have a way to combine existing layers to fix
ALL problems. Dave D'Orio (start telling ya some of the names of a few of the
unsung types here) did a GREAT job of bringing most of the IC design efforts
together.  I was sitting with Dave in a bar, we were of course discussing
work, when he suddenly figured out what the problem was.  He had looked at
the bad MMU chip under a microscope that day.  Later that night, under the
influence of a few Michelobs, his brain "developed" the picture his eyes had
taken earlier and he realized that an earlier layer had gotten into the
design.


30-Jan-93  19:49:06

This would not be the first time a problem would be addressed at this
particular bar.  (The Courtyard.... If you ever saw the David Letterman where
the guy stops the fan with his tongue, he was a bartender there). The PLA had
a problem where my group had made a typo in specifying the hundred some terms
that comprised the different operating parameters. Well the designer in
charge of the PLA took this rev as an opportunity to sneak a change into the
chip without really going public with the fact he was making a change.  When
the change went through it caused one of the layers to shift towards one side
and effectively shorted the input pins together. Ya should've seen the seen
where the designer's boss was loudly proclaiming that Hardware must of
screwed up because his engineer DIDN't make any changes (that would've been
like admitting that something had been "broken"). You could tell by the way
the designer's face was slowly turning red that he hadn't yet found a way of
telling his boss that he had made a change. Talk about giving someone enough
rope to hang themselves, we just kept paying it out yard by yard.


30-Jan-93  19:53:45

Anyways back to the 8563.  The first problem was relatively easy to fix,
providing you didn't give a hang about your own self respect.  The 8563
designer mentioned that the block copy seemed to work better when you wrote
the same command twice in a row.  I made him explain this to me in public,
mostly due to the mean streak I was starting to develop when it came to this
particular subject.  He calmly explained that you mearly wrote to this
register and then wrote to it again.  I asked "you mean do it and do it now?"
"Exactly", the designer exclaimed figuring he was on the home stretch  to
understanding (Intel, at last his eyes unfurled), "kinda like a 'come on
pretty please register' I asked with my best innocent expression, "Well sort
of" he replied doubt creeping in to his voice, "you wouldn't be from Texas
would you", I asked my face the definition of sincerity, (said in the voice
of the wanna-be HBO director on the HBO made for TV commercial) "why yes....
yes I am" he replied. Mind you a crowd had formed by this time, that poor guy
never understood what was so funny about being from Texas or what a 'Damm
Texan' register was.


30-Jan-93  19:53:50

This 'fix' actually did work some what, the only problem was that noone told
the guy (Von Ertwine) who was developing CP/M at home (consultant). Von had
wisely chosen not to try to follow all of the current Revs of the 8563,
instead he latched onto a somewhat working Rev4 and kept if for software
development.  Later we would find out that Von, to make the 8563 work
properly, was taking the little metal cup that came with his hot air popcorn
popper (it was a buttercup to be exact) and would put an Ice cube in it and
set it on the 8563.  He got about 1/2 hour of operation per cube. On our side
there was talk of rigging cans of cold spray with foot switches for the CES
show, "sparkle??? I don't <pissshhh> see any sparkle <pissshhh>". Anyways,
no-one told Von.... but don't worry, he would find out the day before CES
during setup in 'Vegas.


TO BE CONTINUED!