see below, plz.
Dick
----- Original Message -----
From: "Tony Duell" <ard_at_p850ug1.demon.co.uk>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, April 15, 2002 6:40 PM
Subject: Re: TTL computing
> > > > 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...
> > >
> > 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
>
> Fine, so don't offer support on that. Make it very clear that if you want
> to make your own programmer then you are very much on your own.
>
> FWIW, I've only once phoned up a technical support line for a chip. The
> so-called support consisted of reading the datasheet to me. The support
> droid was incapable of answering questions about the device. Since I'd
> already read the datasheet, this was not exactly useful.
>
> > 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.
>
> Why the difference? Why are PLDs a support nightmare if MCUs are not? As
> far as I can see the actual process of programming (say) an EPROM cell is
> the same whether that cell is in an EPROM, an EPROM-based microcontroller
> (like an 8751) or an EPROM-based PLD.
>
> > >
> > > 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
>
> They put in plenty of other features that are not too important, though.
> (like the manufacturer-code byte -- people using them for production
> presumably buy entire batches from one manufactuter, people using them
> for prototyping should be able to read the logo on the package!).
>
> > anybody too cheap to buy a programmer. Those parties aren't likely to
help
> > their sales numbers much anyway.
>
> Hmmm.. There's at least one IC manufacturer who did support hobbyists
> (by giving away samples, releasing the programming spec, etc) and then
> discovered they did rather well when said hobbyists recomended those
> chips for commercial applications. It was basically a form for cheap/free
> advertising.
>
Microcontroller makers seem to provide some simple means for programming their
devices in all cases. Those means are often quite limited, but generally
quite adequate for most purposes.
>
> > > [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
>
> Wrong..
>
> Although I've never seen a programmable chip from HP, HP most certainly
> did sell chips (I don't think they actually made them on their own fab
> lines, though). Example, the 1LB3 HPIL interface chip. It was available
> to anyone who wanted to use one to make an HPIL device. HP sold
> development kits, etc for this chip as well.
>
That's not what I remember about HP's early calculators, though. I attempted
to find out what I could about the HP calculators of the early '70's, since we
had an application for 'em, but all they'd tell us was that everything was
"proprietary" and they wouldn't tell us anything.
We did get 'em to work, but bought the TI calculators instead.
>
> > unfriendly, so I've endeavored to avoid their products. Printers,
notably,
>
> Odd. Until recently I've always found HP to be most friendly to user
> groups, etc. They released a _lot_ of internal documentation that way
> (ROM sources, timing diagrams, memory maps, pinouts, etc). OK, there was
> no support, but it was certainly very useful.
>
That's not how they presented themselves back in '72-73. I wrote them off
then and have avoided them since. Since then I've used only one HP product
line, and that's their optoelectronic devices, e.g. 7-segment displays,
optoisolators. Of course, I do use their printers, but it's not painless.
>
> No, until about 5 years ago, HP were certainly one of the 'good guys'.
>
> > > But as I've said enough times already, the computer and OS to run said
> > > software most certainly are not free!
> > >
> > Tony, YOU've made the choice to avoid the software and hardware that make
>
Linux is supposed to be free.
>
> Well, maybe I had no choice. As I pointed out, neither the computer nor
> the OS are free. I have little enough money as it is...
>
> > things easy. Don't presume to criticize the device vendors for failing to
> > support YOUR hobby.
>
> Firstly, I am not critising them. I'll just choose not to use their
> products. Now will you please stop flaming me for making that choice.
>
This isn't a flame, it is a caution that you may be isolating yourself from
the current technology, and that technology would make things much easier for
you. With the programmable hardware you wouldn't have to resolder wires in
order to make changes, and you wouldn't have to change connector pinouts
because you changed the internals of a circuit. Maybe you should consider
DOSEMU and WINE on some LINUX box. Then you could spend your time
experimenting with those theoretical concepts as you want to, and generate no
wasted hardware.
>
> However, there's also a difference between 'not suporting' and
> 'preventing others from supporting'. I don't expect Philips or Intel to
> sell me an 8051 cross-assembler for linux
they won't sell it to you, but they'll give you what they have available, and,
with a little web-search, you can find useable source code that can easily be
adapted to whatever compiler you have.
> (or for RT11, or...). But I can
> take the published datasheets and write an assembler. The information is
> there (opcode map, etc). But in the case of PLDs not only will the
> manufacturers not sell me software for my choice of OS (reasonable), they
> also won't provide the information to let me (or others) write that
software.
>
The PLD vendors will sell you software for LINUX if they don't give it away,
though I don't expect they'll support RT11 or OS8.
>
> > > > 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!
> > >
>
You just tell them that to protect yourself. If you suggest that they build
it, you could be considered liable for the solder splat on their lap, and for
the burn on their privates if they were doing it in their skivvies.
>
> > 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.
>
> I am not sure you quite understood what I was saying, but....
>
> Considering I want to publish circuits (in the same way that some people
> like giving away free software), the obvious choice for me is not to use
> programmable devices unless I really have to. Then there are no support
> problems for me.
>
and it's generous of you to want to do that, but there are risks.
>
Using SSI/MSI parts makes for the greatest likelihood the end-user will be
able to implement your design, but it doesn't increase the chances of
completing the work, since the supplies of many of those old parts are finite.
I have a couple of old circuits I published back in the '70's, for which I
doubt anyone will find parts nowadays. If someone becomes accustomed to using
one of these gadgets, I wonder how they'll get replacement parts. There was a
time when when TTL was "THE" way to go. That time has passed. The stuff
still works and you can still blink lights as you always did, with the stuff,
but it's just not the technology of choice any longer. Wait till someone sues
you for using parts, in your published design, that he can't get.
There's free software to enable the casual user to develop his own logic in
programmable devices, and there's free software to drive hardware that does
the programming using circuitry provided for free by the device vendors, to
run on the popular OS'. Most folks use those.
If, for whatever reasons, you decide you don't want to run those more or less
current OS' or the platforms that support them, it's a choice you make. I
routinely see completely functional hardware capable of running the popular
OS' in the surplus vendors' stores for <$80. I bought a complete HP PC unit
for less than that a few months back, just to pass it along to a friend who
didn't have much budget.
There's certainly no reason why someone who's already got a range of hardware
can't accomodate that in his budget and environs IF he wants to, so it comes
down to a choice, which everybody's free to make for himself.
I'm sure you understand that IC vendors in business to make money by selling
their IC's in volume really can't afford to spend more than 100ps per day on
hobbyists. With that short a time budget, they certainly have to focus on the
larger part of the hobbyist market. It's not likely that they'll put out a
version for the PDP8.
>
> > > 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.
> > >
> > I don't think that's a choice either of us is qualified to make.
> > >
> > > 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.
>
> No. I have no desire to remain in the world if I am going to be sued for
> providing information in good faith. Just because I am not clever enough
> to spot the cheapest way to solve a particular problem.
>
If you want to minimize your risk profile, you avoid certain exposures.
Nowadays, if someone inadvertently sticks his screwdriver in the wall plug and
harms himself, while assembling your circuit, you could be viewed as liable.
You provided the information in good faith. His lawyer says you should have
warned him against inserting his screwdriver in the mains while standing on a
wet kitchen floor ...
Received on Mon Apr 15 2002 - 22:51:07 BST