Ah, my mistake. Sorry for the false hope. Best, -Mark On Mon, Sep 30, 2019 at 12:59 PM Tony Bogan <thebogans@mac.com> wrote:
Mark, that’s the computer interface card. I believe Evan was talking about the controller board (Interface -a)
http://4.bp.blogspot.com/-ixfYuILNd9I/U-3meTkPvkI/AAAAAAAAAYI/oqF0-8v-42w/s1...
Tony
Sent from my iPhone
On Sep 30, 2019, at 11:16 AM, Mark Whittington via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Looks like someone on this list has already done the legwork on this as of 2016...
https://www.glitchwrks.com/2016/09/12/lego-logo-interface
On Mon, Sep 30, 2019 at 9:13 AM Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
If you're interested in investigating further if you point us to
schematics we can give suggestions.
I am giving the box to Neville in early November (don't want to risk it not
working before the Brickfair NJ event the first weekend of that month). He
agreed to my request to make a schematic of it.
The next step will be to have someone else take his schematic, build one,
and send it back to me for testing. That'll prove that the box can in fact
be built from just the plans. After that I'll post it on my website.
A possible third stage would be to make modern improvements, if any ideas
stand out.
I'm only interested in the function, not in replicating the physical case.
But what I would avoid is replacing the vintage computer with a
microcontroller. I'm all for a better interface but strictly against some
non-vintage computer experience.
On Mon, Sep 30, 2019, 8:43 AM David Gesswein via vcf-midatlantic <
vcf-midatlantic@lists.vcfed.org> wrote:
It's called a 'crowbar' circuit. Prevents things from burning up.
What I normally called a crowbar circuit is the overvoltage protection
where it intentionally shorts the output of the power supply. This sounds
more like over current protection.
What are common reasons why those stop working? Neville and I didn't
see
any obvious signs of damage to it.
Either component value shift or failed component. You indicated that it
is
driving the motors better than it ever has. It may also be your motors
are a heavier load than it was intended to drive.
If you're interested in investigating further if you point us to
schematics
we can give suggestions.
On Sun, Sep 29, 2019, 1:56 PM Mike Loewen <mloewen@cpumagic.scol.pa.us
wrote:
On Sun, 29 Sep 2019, Evan Koblentz via vcf-midatlantic wrote:
Neville noticed something that I wouldn't have. The circuitry
contains a
safety mechanism to shut off all power if the current jumps too
high,
such
as a kid inserting a paper clip. There's probably a technical name
for
that
but I do not know it. Anyway, for unknown reasons this circuit was
kicking
in! He jumped it with an equal-length wire. :)
It's called a 'crowbar' circuit. Prevents things from burning
up.
Mike Loewen mloewen@cpumagic.scol.pa.us
Old Technology