Comment in Boeing crash article

[tommolica]

1 hour ago
 (Edited)

I worked on optimizing the 429 ARINC I/O controller for the 737-300
around 1990, but I don't think I broke anything.  That 32 bit data
bus controller had a weird glitch where it would reset when more
than 21 bits of the 32 bit word were 1s.  Weird.
The was the last thing I fixed before leaving Michigan
and returning home to Florida.

At the time, we didn't have the POPCNT instruction used
by today's Intel processors.   This board used a Z8000
which I spent a lot of time working on with other avionics
contracts.

Now?  Just cut grass and take care of the chickens.

-- Just some useless info for my Social Comment File.

I don't know anything about programing, but this sounds amazing.

[buster]

Cutting grass, taking care of chickens, and warm weather sounds good, although that usually means you're old like me.

I'm curious why you picked a Linux site to register at, and why one in Canada, even though we are the most wonderful country in the world - never great, but pleasant and usually polite.

I understand you wish to inform people you didn't break the airplanes. But Peterborough, Ontario?

By the way my wife and I have spent a number of spring seasons wandering about your wonderful State Parks, and not the ones near the sea, but inland where life is quieter.

[tommolica]

Hi Buster, just thought it was interesting that a processor in one of the control systems would reset when too many 1's were loaded into a certain register.
Bill also checked to make sure it was me, and not someone who had hacked my account.
I thought it might be interesting that processors with such quirky behavior would be still be kept in any production device at all. wonder if any desktop CPU's have any strange behavior like that??  Cheers Tom.