Re: Did Commodore cheat with the quad density floppies?

On 9/1/19 12:45, Gerrit Heitsch wrote:
> From what I read, Commodore had planned to do a rework of the 1541 using
> a 6526 (probably like in the 1570/71, or just replacing one 6522 with a
> 6526), but someone deleted the necessary traces to use the shift
> register from the C64 schematics and when that was found, they already
> had a lot of boards produced. So they dropped the rework of the drive
> and went with bit banging I/O. And they even had to slow that down
> compared to the VIC-20 due to the badlines VIC-II introduced.

Check the great book "Commodore: a company on the edge", page 423. Sorry
for the crappy copy&paste from the EBOOK:

"""
Russell finally received a C64 circuit board and began examining the
finished product. “I’m
doing the tests and everything is working fine because we hadn’t written
the high-speed
code yet,” he recalls. “Then I looked at the board and said, ‘Where are
the high-speed
lines?’” Someone on the west coast had changed Russell’s schematic.
“The production guys took them off when they did the production boards.
I put high-speed
lines on and they deleted them,” he says.
When Russell realized what happened, he was livid. “I threw a hell of a
fit,” he recalls. He
was determined to find out why someone had neutered his high-speed
serial bus. “I trackedit down and it was the production engineers in
California who cut it off.”
To make the board fit in the cramped VIC-20 case, the engineers removed
the traces for thehigh-speed lines. “The guys that actually did the
production board layout cut off the signals
to save some money,” explains Russell. “They thought, ‘Why are these
extra lines running tothese signal pins?’ So they chopped them off and
screwed us.” It was like building an eight
cylinder engine with eight fuel lines and cutting off seven of them.
Russell was determined to rescue the disastrous situation. “I ran down
to Charlie, throwinga total fit. He says, ‘Well is it still functional?’
I said, ‘Yeah, it still works as a 1540.’”
Winterble looked into the situation and found out the production
facility had manufacturedtoo many circuit boards already. “We couldn’t
change it after hundreds of thousands of
PCBs were in production,” laments Russell.
Stopping production on the C64 and restarting it with a new design was
out of the
question. “Technically it would have been possible, but you’ve got to
realize, they were
already moving their production and going to ship,” says Russell. “If I
had done that, it
would have been several weeks until I got a finished unit for evaluation.”
If Russell attempted to make changes now, early customers would be
extremely unhappy.
“There would have been a bunch of machines out there that would have been
incompatible,” he explains.
It was now pointless to design a faster 1541 drive. “We never bothered
spinning another
drive,” says Russell. “The 1541 became just a 1540 with minor software
changes.” The
deletion of a few metal circuit traces ultimately resulted in millions
of wasted hours for C64owners.

[...More interesting technical details follow...]

"""

I found this book amazing and unusually full of technical tidbits. Maybe
the best computer history book I have read.

-- 
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