On Tuesday 25 June 2013 04:08:40 MC Cason did opine: > Gene, > > Since you just LOVE the PDP-11s, this should make your day: > http://www.theregister.co.uk/2013/06/19/nuke_plants_to_keep_pdp11_until_ > 2050/
That is one of the articles that prompted my tirade. First off, its nowhere near rad hard, and AFAIK only 2 of the older CPU's would qualify, the RCA 1802 family, and the Hitachi cmos workalike clone of the motorola 6809, the HD63C09EP. But thats much newer than the 1802. While the HD63C09EP is a much more powerful CPU, the 1802 was well established, and was enough to get the job done by the time the Hitachi chip came out. And Hitachi's agreement with moto was not for masks, it was to reverse engineer the clone. But they used a different layout, in cmos, and filled the empty spots in the 6809 op-code map with newer, more capable instructions. Like a canned routine to divide a 32 bit value with a 16 bit value, giving the result and modulo 16 bits answers, in 39 clock cycles worst case. Any control computer in a nuke facility really should be rad hard, so that it can continue to function right up to within a millisecond of being a glow in the dark crater in the ground. Those PDP-11's aren't. RCA 1802's are yet today, used in the oil exploration business as part of a downhole surveying tool functioning as the interface between a multi-curie rad source, and an alpha detector that measures the alpha coming back from the rock, which indicates how much oil is in the rock. Operating 6" from a multi-curie src doesn't bother it a bit. > On 06/24/2013 01:13 PM, Gene Heskett wrote: > > On Monday 24 June 2013 13:59:47 Stuart Stevenson did opine: > >> wonders never cease > >> I just saw a link for a PDP-11 assembly programmer for a job to last > >> until 2050 > >> seems as if anything is possible > > > > Even including that insanity, because based on my experience with a > > PDP-11/723, that would have to be considered insanity. That thing was > > a crashomatic, several times an hour at the end, and since it took > > something like 15 minutes to boot because compiling the program it > > ran was part of the boot sequence, the uptime was less than 50% of > > the time. DEC replaced everything in that machine but the frame rail > > with the serial number riveted to it and every time they touched it, > > they made it worse. > > > > My problems with that single example caused the CBS tv network to > > replace every machine at every CBS affiliate with industrial IBM's & > > new software, on their nickel. That thing probably cost us $100k or > > more in lost commercial revenue because it had silently crashed, and > > a channel change wasn't done on time, so we were airing a dog food > > commercial we didn't get paid for in place of the toothpaste > > commercial we would have been paid for had the channel or bird switch > > been done on time. > > > > No, I do not remember the PDP-11 days fondly. :( > > > > Cheers, Gene Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Tip the world over on its side and everything loose will land in Los Angeles. -- Frank Lloyd Wright A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
