Forums

How to choose a firmware partner

Started by robi...@tesco.net May 26, 2004
"Phil" <please@sendmejunkmail.com> wrote
> > "Anthony Fremont" <spam@anywhere.com> wrote
> > A full megabyte....in the 60's?....that's pretty big. I programmed
on
> > WWMCCS GE/Honeywell mainframes in the early 80's that didn't have a
full
> > megabyte of magnetic core memory. > > > > I would be interested (and surprised) to know which > computer had a megabyte of core in the 60's. > see http://www.crowl.org/Lawrence/history/computer_list > to help "refresh your memory" (bad pun). > I worked on Elliot 920B's (not on the list) perhaps > because it was military??
I would like to know as well. I worked on Honeywell 6000's and when I say early 80's, I mean July of 1980 and on. IIRC (and I think I do ;-) they had about 128K words of core, and each word was 36 bits. They really didn't use "bytes" allot, as the native character set was BCD (6 bits/char). They also had ASCII support (sort of ;-) where there were 4 "must be zero" bits per word. Bits were numbered from left to right, IOW Bit 0 was the MSB. The first 64K words was the "hard core monitor" or HCM and was the nucleus of the OS. The machine was an evolution of the GE 635 which was a bit simpler, and before my time. I could go on, but I'll stop before I bore you to death. I really miss that architecture from a low level point of view, it was a real beauty in it's own right. :-( For real-time response and transaction processing they always kicked IBM's butt. Shows the power of a good marketing program.
On 26 May 2004 03:02:23 -0700, robin.pain@tesco.net
(robin.pain@tesco.net) wrote:

>Ask if it's policy to enable the watchdog timer. The correct answer is >"no". > >If they say "yes" then you know that their code is dodgy, and/or their >hardware is vulnerable and if the WDT is not going off occassionally, >it probably will after the next modification.
If you write 100% correct code on a 100% correct platform, you don't need it. But the more complex an application gets the more likely it is that there might be a race-condition not foreseen. (Or do _you_ test your system with __all__ possible input values ? I bet no !) And I'd rather see nuclear-powerplant computer reboot than staying in an endless loop :-) --- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
>> The watchdog timer is a fairly recent invention, millions of older systems >run >> fine without them. > >It's exactly as old as embedded microprocessors. (I know. I was there.) It's >dumb having one without the other.
And it is even not an invention of electronic-age. - railway-signals used to have something alike - dead-man button in trains --- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
On 26 May 2004 15:35:23 GMT, cbarn24050@aol.com (CBarn24050) wrote:

> >The watchdog timer is a fairly recent invention, millions of older systems run >fine without them.
Fine. That is why I have to power-cycle my settop box from time to time. If they only had build in a WDT, I would not have to climb behind my TV (of course the settop box has no switch, also a new _invention_). --- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
> >Errr... yeah, but do you remember how much those suckers used to cost? I >think the iPDS cost us (with ICE, which was around half of the total, IIRC) >around 13 kilobucks... Back then development systems were major capital >investment. Nowadays it's a PC and GNU ;). >
Can't agree here. GNU ok. PC ok. But for embedded debugging I really appreciate a full blown emulator (of course these are dieing). --- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
>>> If they say "yes" then you know that their code is dodgy, and/or their >>> hardware is vulnerable and if the WDT is not going off occassionally, >>> it probably will after the next modification. >>> >>> Cheers >>> Robin >> >>I give it a 3. Not terribly original, but it is getting responses. > >Yes, the TROLL-O-METER needle is flickering upscale a bit.
Damn, I got trapped :-) --- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
"Phil" <please@sendmejunkmail.com> wrote in message
news:c93gv9$c2s$1@hercules.btinternet.com...
> > > I would be interested (and surprised) to know which > computer had a megabyte of core in the 60's. > see http://www.crowl.org/Lawrence/history/computer_list > to help "refresh your memory" (bad pun). > I worked on Elliot 920B's (not on the list) perhaps > because it was military?? >
In the very late '60s I worked on a UNIVAC 1110 which had that much memory but I can't say now if it was core or semi. Norm
Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote in message news:<v1c9b01lvf8cgr8v0tpnrqq68scujkalih@4ax.com>...
> On 26 May 2004 13:54:08 GMT, the renowned Richard > <RichardRapier@netscape.net> wrote: > > >robin.pain@tesco.net (robin.pain@tesco.net) wrote in > >news:bd24a397.0405260202.5241051c@posting.google.com: > > > >> How to choose a firmware partner: > >> > >> Ask if it's policy to enable the watchdog timer. The correct answer is > >> "no". > >> > >> If they say "yes" then you know that their code is dodgy, and/or their > >> hardware is vulnerable and if the WDT is not going off occassionally, > >> it probably will after the next modification. > >> > >> Cheers > >> Robin > > > >I give it a 3. Not terribly original, but it is getting responses. > > Yes, the TROLL-O-METER needle is flickering upscale a bit. > > Best regards, > Spehro Pefhany
So this may seem (a troll), to some people, but won't anyone even consider this for a moment: 1) A one byte loop is lockup-proof. 2) So for a standalone, MCU, lockup proof code is only a matter of scale. 3) Evidently the MCU hardware itself cannot become inherently "stuck" because that would make the clearWDT instructions inaccessible and a mockery of the whole watchdog scheme. I am guessing that the above posters are talking of complicated, multiproccessor, asynchronous systems; which is a little narrow minded. A better response could be: "The OP probably means 1/2k of code running in a 12C505, heh heh, he'll grow up eventually!" Cheers Robin
On Thu, 27 May 2004 06:57:19 GMT, "Norm Dresner" <ndrez@att.net>
wrote:

> > In the very late '60s I worked on a UNIVAC 1110 which had that much >memory but I can't say now if it was core or semi.
In the 60's, it must have been core. In the mid-70's, the PDP-11/70 physical address space was 4 MB, but with original DEC core modules, two full size cabinets would be needed to hold all those core modules. However, connecting all these would have violated the memory bus length limitation. Thus, with core memory, the maximum memory capacity would have been IIRC 1 or 2 MB. In 1977 or 1978 Intel sold semiconductor memory modules built around 8 kbit x 1 DRAMs. With these modules 4 MB would fit into one cabinet and the memory bus length was within specification. In those days the largest DRAMs Intel made was 16 kbit x 1, so apparently they used those 16 kbit DRAMs with a defect in one half of the memory plane and used as 8 kbit devices in their own modules. In those days DRAMs suffered from soft errors, apparently due to alpha particles emitted by the plastic package, thus the modules had ECC instead of parity, which was the norm for core memories in those days. Operators manually logged the error status registers on the module before resetting the counters. Frequent failures in a particular chip required replacing it sooner or later. While computer systems with 1 MB of memory could have been done in 1975/76 using 4 kbit x 1 (requiring 2000-2500 DRAMs), but I doubt that making 1 MB with 1kbit x 1 SRAMs (requiring 8000-10000 chips) would have been very practical due to the high power consumption. Paul
Norm Dresner <ndrez@att.net> says...
> >"Phil" <please@sendmejunkmail.com> wrote... >> >> I would be interested (and surprised) to know which >> computer had a megabyte of core in the 60's.
1n 1965 The Sperry Rand UNIVAC 1108 II (aka 1108A) had two memory cabinets with 262,000 64 bit words each, which adds up to nearly 2MB.
>In the very late '60s I worked on a UNIVAC 1110 which had that >much memory but I can't say now if it was core or semi.
Are you sure it wasn't an 1108 or 1106? The 1110 was introduced on November 10, 1970. (Many web pages say 1972, but they are wrong.) The 1110 had a full megaword of memory, which is over four megabytes (36 bit words). It also had plated wire memory in addition to the core. In 1976 the 1110/40 came out, which was an 1110 with a megaword of (faster) RAM chips instead of core. -- Guy Macon, Electronics Engineer & Project Manager for hire. Remember Doc Brown from the _Back to the Future_ movies? Do you have an "impossible" engineering project that only someone like Doc Brown can solve? My resume is at http://www.guymacon.com/