Bad Feelings...

From: Sam Ismail <dastar_at_crl.com>
Date: Sun Jun 22 19:27:42 1997

On Sun, 22 Jun 1997, A.R. Duell wrote:

> Yes, but it some cases the 'kludges' led to problems later on - 'trivial'
> problems like a total incompatability between the Disk II and just about
> any other machine in the world, 'mariginal behaviour' like a case that
> overheated, a PSU that was beyond the design limit when running a system
> board, language card and 1 drive, things like that that caused some
> machines to crash after about 1 hour, that _crazy_ slot addressing scheme
> and the saving on chips/PSU consumption by switching the power line to
> the I/O card ROM - I may be old-fashioned, but I don't like driving input
> pins past the supply rails..., etc
>
> Saving components is only 'good' when it doesn't affect performance. I am
> not convinced that this is the case with the Apple ][

OK, now you're just outright wrong. I've never had any of the problems
you mentioned above with any of my apples. The only problems I ever had
was when I pulled the disk controller card from my ][+ when it was still
powered on (I was young and lame). As far as the system over-heating,
nope. Never happened. PSU beyond the design limit when running a system
board? What on earth are you talking about? Crashed after an hour?
Mine never, ever spontaneously crashed, and I've owned several. Crazy
slot addressing scheme? I think it wored rather well. And the language
card was for the ][+ to have backward compatibility with the ][. That's
bad design? Actually, that's called "customer friendly".

Of course, you're entitled to your opinion Tony, but I think it's driven
mostly by ignorance (I don't mean that in a bad way) or just plain bad luck.

> Oh, please don't think I am picking on Apple. The PERQ (my favourite
> machine) has a number of _very_ marginal timings. The various CPU board
> clocks are delayed with respect to each other by a string of TTL inverters
> and buffers. Some memory cards will only work in landscape mode - the
> timing is 'on the edge', so that the portrait mode doesn't work. And for
> those that do work in portrait mode as well you often have to change a
> coupld of chips to slower versions (say a 74S157 -> 74LS157) to get it to
> work correctly.

If what you described above is correct, then did it work? If so, it
wasn't such a bad design after all, was it? If not, then yeah, the design
sucked. What you describe here, in contrast to the Apple design, is in
fact poor design. The Apple ][, as designed the way it was, worked fine.


Sam
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Computer Historian, Programmer, Musician, Philosopher, Athlete, Writer, Jackass
Received on Sun Jun 22 1997 - 19:27:42 BST