14 Apr
2002
14 Apr
'02
9:57 p.m.
see below, plz.
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, April 14, 2002 12:36 PM
Subject: Re: TTL computing
I don't think it's bogus. There's a big difference between telling the
user,
in the datasheet, how to program his device and in fielding a phone-call
regarding that matter. The mfg's know how many phone calls they have to deal
with in connection with that sort of question and it didn't take them long to
figure it out.
Intel published the spec's on how to program their programmable devices
including MCU's. The didn't however, publish the programming specs for their
PLD's.
Tony, YOU've made the choice to avoid the software and hardware that make
things easy. Don't presume to criticize the device vendors for failing to
support YOUR hobby.
I don't think that's a choice either of us is qualified to make.
> > Not that I've seen. The early MMI PALs
(which were about the first ones
> > to be made) used a strange programming algorithm (IIRC you had to
program
> > the chip in 2 halves, and the functions of
pins swapped deneding on
which
> > half you were programming). But at least the
algorithm was published so
> > you could make your own programmer. Most manufacturers these days do not
> > publish the programming algorithms :-(
> >
> The stuff was published, but that didn't mean just anyone would even want
to
tackle the
problem. Today, publishing the programming algorithms would
Did I say they had to? Those who had the money could buy a programmer.
Those who had the time could build one. Same choice as with so many other
things.
produce a service headache for them, so they
don't do it.
I've heard this bogus argument so many times.... Plenty of
microcontroller manufacturers publish the programming algorithms for the
EPROM or flash ROM inside their chips, and presumably it doesn't cause
them too many problems...
In any case, all the manufacturers would have to do is put one more
location in the chip that can only be programmed on an 'approved' device
programmer. This location has no effect on the operation of the chip, but
it can be read out. The method of programming it is the one thing left
out of the published spec. If somebody is having problems with the chip
then unless they have managed to program this bit (== are using a
commercial, approved, programmer) then they get no support [1]. And if
you claim that misprogramming the chip could damage it so this location
could not be inspected, well, true, but then again, applying mains to the
Vcc pin will do that anyway!
This would cost 'em millions, and they save those millions simply by ignoring
anybody too cheap to buy a programmer. Those parties aren't likely to help
their sales numbers much anyway.
[1] I've seen many HP documents that were distributed to user groups
under the NOMAS scheme. NOMAS = NOt MAnufacturer Supported. In other
words, use and enjoy the information, but we're not going to help you any
more. Needless to say, such information (which included things like ROM
source listings) is very valuable.
HP is not an IC vendor. Their practices have always been what I've considered
unfriendly, so I've endeavored to avoid their products. Printers, notably,
are an exception to this policy.
> Devices (SPLD) are pretty cheap, and, quite common nowadays. The software
is
free, and
today's small devices are reprogrammable so they can be
But as I've said enough times already, the computer and OS to run said
software most certainly are not free!
> > I've also learnt the hard way that if you're designing something that
you
> > want other hobbyists to build, then avoid
programmed chips. Almost
nobody
> > has a device programmer, so you end up
having to supply programmed
chips.
> > That's bad enough, but you're also
expected to replace them free when
> > they don't work (even if the idiot has tried to run them straight off a
> > car battery).
> >
> If you don't sell 'em anything, you can't be held responsible for what
they do
True. That was the first part of the comment. Nobody has a device
programmer, so they can't build your design. You end up getting dozens of
e-mail messages asking 'please can you sell me a programmed PIC for your
<foo>'. And you sell them one, and the support nightmare starts. Never
again!
> with it. If they buy a few parts from somewhere and abuse them, it's not
on
> you. If you specifically tell them they're
not allowed to build your
> circuit, as you retain the rights to it, but choose to share the
information
Odd, but when I publish a circuit, I expect people to want to build it. I
am not doing this as some kind of 'how clever I am' advertising!
If you don't want the associated headaches, don't publish the circuits.
That
is the choice that the programmable logic vendors decided to make.
> contained in it anyway, you certainly can't be held responsible if they
build
> it. Just wait until someone sues you because you
used parts in your
design
that cost more
than some other combination of parts, thereby causing their
costs to go up. That'll get you to stop that sort of stuff.
If somebody is so stupid that they can't analyse the cost of my circuit
against the cost of another one (including any necessary design time),
then to be honest, they're not fit to be alive.
And if I am ever sued for something like this, then I will probably
fatally autoLART...
You're putting your fate in someone else's hands, Tony. I'd rethink
that
option.