[ale] [OT] Mars Lander!

[Lightner, Jeff]

Mention of Hex patching remindse me of early computerized cash registers from NCR called the 2160.   I don't know if it was hex patching but what they had to feed in looked like pure gobbled-gook to me at the time.

At one place I worked they'd been having issues long before I got there and still after I got there wherein periodically things would go out of balance.   There were 3 separate totals that should balance and they usually did but on occasion the 3rd one didn't.   They told me about it and said NCR was working on it so I should ignore it when it happened.   Within a month I'd determined the issue was always multiples of $175.00.   There was a seemingly separate issue where when run ran an account reading its bar code it would suddenly display a very large number it was about to post and when that occurred I was told to hit escape and input the right number.  I noticed within that same month that any time this occurred the very large number was always the expected number + $175.00.   Once I realized both these things I looked at the detail tape for the transaction and found that sure enough although the account displayed 0.00 for the number after the escape the detail tape was instead showing the $175.00.   What really got me was when I reported it to NCR the programmer said "oh yeah, we saw that somewhere else".   In months of "debugging" it didn't occur to them to check for known problems?





-----Original Message-----
From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of JD
Sent: Tuesday, August 07, 2012 7:04 AM
To: Atlanta Linux Enthusiasts
Subject: Re: [ale] [OT] Mars Lander!

On 08/06/2012 10:33 PM, Michael H. Warfield wrote:
>  and they had to exploit and unintended backdoor in the machine to
> regain control

I know they've patched the shuttle using manual inputs in hex.  Those computers had that facility built-in and fully documented.  It definitely was not a back door. The hex patch capability is like a deadly pill carried by spies.  Nobody wants to use it, but there are thousands of scenarios where it could be useful.
It is really hard to correctly patch a system with dynamic memory allocation.
The programming language used on the shuttles didn't do dynamic memory allocation. Every bit in memory was known. Heck, I had to get a waiver to use a pointer to access elements in a huge array because it was larger than the HAL/S compiler supported.

In the mid-90s, I had a different job at JSC working on the shuttle and station flight control rooms writing software and managing an app.  They were hundreds of DEC Alphas used, with a few HP-UX (2 or 3) and a few AIX (1-2) and 2 SunOS HA NFS servers.  PCs were forbidden on the network.  If you ever see the blue consoles at JSC on TV for space station support, those were the control rooms that my company installed - everything from networking, hardware and almost all software was included in the contract.  I think they moved one of the FCRs somewhere else in Bldg-30-S in 2004, but can't figure out where. There were 4 FCRs when I was there. 2 were Apollo era and 2 were brand new.  I thought the old FCRs would never be touched, left for history.  They weren't sealed, I've sat in the Apollo FD chair when the room was empty.  What I remember thinking is "I"m not worthy."

The app my team wrote was deployed to every POCC around the world and on the laptops for shuttle and space station flights. I installed it on all the workstations everywhere, POCCs, FCRs, launch rooms ... but only once on the astronaut laptops.  I rubbed someone the wrong way during an initial training session. One of them asked a question about the storage on disk, which was pretty tiny, except the data for the program was huge and not stored on the disk. He didn't like my answer, yelled at me and I was out.  I figure he was having a bad day, one of the others told me that as I left.  Very high stress job and being on call 24/7 sucks. I wasn't allowed to leave town. Even when a mission wasn't flying, the software and FCRs were used constantly for training.


I was only there 7 yrs, but it was pretty amazing work and my job had some pretty cool access.  Some of it sucked too, like all the disconnected networks that needed user account maintenance all the time ... I'd spend half a day walking around changing passwords every 28 days.  Most of the developers worked 100% in secured environments and networks. My team worked on the internet and I had to "introduce" the code to the more secure networks. Our project had a way to bring data in that didn't go through the same cumbersome method with lots of paperwork. That was my job too.

Sorry to go on so long. I don't want to bore you with JSC stories.
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