wmartin@brl-tgr.ARPA (06/07/85)
I have been hearing and reading disturbing things about electronic components simply "wearing out" from use, or circuit designs which use batteries for volatile ROMs and which will become useless after some period of time unless deliberately maintained. The former example includes a recent net.audio posting about the laser assembly in a CD player having to be replaced after 5 years or so of use, and the latter includes the control programming for the ICOM (and other brands) of shortwave receivers and amateur equipment, wherein an on-board battery must stay alive to keep a ROM programmed to keep the radio in operable condition. This troubles me. I had thought that we had a reasonable progression of development of electronics during these days of solid-state gear replacing tube equipment that meant longer life for any device. LED's with essentially eternal lives replaced easily-burned-out incandescent lamps. Transistors replaced tubes, and ICs and VLSI replaced discrete components, and, assuming weeding out infant mortality and no actual damage to the circuit, like overvoltage, it should continue to operate indefinitely. Dipped caps replaced paper ones, etc. But now I see that designers either deliberately build in inevitable failures (the use of volatile ROMs and batteries instead of PROMs or other permanent devices) or the solid-state stuff I was led to believe had indefinitely-long lives really is as short-lived as vacuum tubes (the laser diodes mentioned above). I may be insane, but I really expect electronic equipment to operate forever. I don't want to buy any that has built-in and inevitable failure. I have a lot of old gear, some older than myself, that still works. I expect this tube gear to wear out from heat and voltage stresses but it hasn't yet. If I buy new stuff, without the tube-caused heat and high-voltage stress, I expect it to last longer than I will! I realize that consumer products have built-in planned obsolescence. I'm not talking about small appliances, which I expect to die and be replaced. I'm talking about multi-hundred-dollar equipment. Am I totally unjustified in expecting such things to be designed to continue to work indefinitely without maintenance, except for mechanical stuff like motors, belts, pots, etc? (I would expect to maintain anything mechanical -- purely electronic gear is different.) Am I alone in this concern? Regards, Will Martin USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
zben@umd5.UUCP (06/09/85)
In article <11251@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: >I have been hearing and reading disturbing things about electronic >components simply "wearing out" from use, ... >I may be insane, but I really expect electronic equipment to operate >forever. ... >Am I alone in this concern? >Will Martin >USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA Don't forget that data saved in FAMOS (Floating Avalanche Metal Oxide Semi) memories like 2732, 2764, etc is only guaranteed for a mean of 100 years! I guess I'm thinking of early-sales versions of computer-controlled gear that were shipped with EPROM instead of real ROM. For example, the first person in our group who got an H19 got two 2716s, the next got two 2316s (same pinout hard ROM), the next got one 2732, the next got one 2332 etc. -- Ben Cranston ...{seismo!umcp-cs,ihnp4!rlgvax}!cvl!umd5!zben zben@umd2.ARPA
dep@allegra.UUCP (Dewayne Perry) (06/11/85)
[even i get tired of eating all this crap ...] I have a Luxman digital tuner with button selection for my frequently used stations. Natuaraly, the station frequencies are stored in battery-backed rom. My second battery has now gone west. Now that in itself is not too much of a problem. After all, I have had the unit for 7 years now. BUT, to replace the battery, you practically have to send the whole unit back to Luxman - it is soldered into the bottom of two boards and is completely unreachable except by taking the entire unit apart, board by board (they are stacked on top of each other). GREAT design - just imagine if your camera were done by the same designers! Obviously electronics are always better than mechanical solutions. Dewayne
michaelk@azure.UUCP (Michael Kersenbrock) (06/12/85)
[] > I have been hearing and reading disturbing things about electronic > components simply "wearing out" from use, or circuit designs which > use batteries for volatile ROMs and which will become useless after > some period of time unless deliberately maintained. The former > example includes a recent net.audio posting about the laser assembly > in a CD player having to be replaced after 5 years or so of use, and the > latter includes the control programming for the ICOM (and other brands) > of shortwave receivers and amateur equipment, wherein an on-board > battery must stay alive to keep a ROM programmed to keep the radio in > operable condition. I own one of those amateur radio devices (actually a Kenwood). After five years or so, when the battery goes dead, I do not intend to pay out several hundred dollars to replace the radio. I plan to pay two dollars and replace the battery. It's just a little lithium cell that keeps the 4-bit CMOS uC alive when the radio is turned off. (Actually it isn't even necessary except that you'd have to reprogram the radio everytime you changed out the ni-cads to another battery pack). Other uses (like terminal baud rate storage, etc) would be similar. It may be a pain to waste several minutes every 5 years to reprogram whatever the battery went out in, but then ... Mike Kersenbrock Tektronix Microcomputer Development Products Aloha, Oregon
moroney@jon.DEC (Mike Moroney) (06/13/85)
I have to agree with you. I will never knowingly buy an electronic device which depends on a battery keeping a RAM alive, especially when ROM's of the same size are cheaper. -Mike
dca@edison.UUCP (David C. Albrecht) (06/17/85)
> I have to agree with you. I will never knowingly buy an electronic device -> which depends on a battery keeping a RAM alive, especially when ROM's of the > same size are cheaper. > > -Mike Do WHAT? I don't remember the original posting but I would imagine the RAM is used to store transient information such as station presets and perhaps volume settings. A ROM? be serious, you can have any color you like so long as it's blue, and volume you want so long as it's 5 any station you want if you can get them to move to 101.2 :-) David Albrecht General Electric
henry@utzoo.UUCP (Henry Spencer) (06/17/85)
Unfortunately, there really are wear-out mechanisms even in semiconductors. They are less obvious than the ones in tubes, but no less real. Plastic IC packages (used for most ICs in commercial equipment) are not hermetically sealed, and may eventually develop leaks that let air and moisture at the chip; the resulting corrosion kills it. Why do you think the military uses ceramic (truly hermetic) packages almost exclusively? Diffusion does occur even in solids. Various forms of material migration can occur in the presence of electric currents. These things are significant concerns to semiconductor manufacturers. Remember that commercial ICs are optimized for low cost rather than ultimate maximum lifetime. Power spikes, static, and similar forms of overstressing may possibly account for a significant fraction of semiconductor failures in the field. It is very difficult to shield completely against such things, although "99%" protection is much easier and increasingly common. Note that power behavior during powerup and powerdown is rather ill-specified and hard to control completely. EPROMs and EEPROMs inherently have limited lifetimes if they are being reprogrammed regularly, because the erase/program techniques involve pushing electrons through materials that are normally insulators. The technique used to do this is basically brute force. This unavoidably involves some degradation of the insulator. Do it too many times, and it won't insulate any more. EPROMs and EEPROMs will *eventually* lose their contents anyway, because they rely on holding charge on very-well-insulated electrodes. Although the insulation around those electrodes is of truly superb quality, it's not perfect, and the charge will leak off eventually. In the absence of unusual stress, this takes a very long time. Nobody is quite sure how long, because we haven't had the devices that long! Extrapolations from stress tests may not be 100% valid, although they do give hints. Circuit designs which use batteries for volatile memories simply need their batteries replaced occasionally. They don't "become useless" any more than a flashlight becomes useless, although in some cases the battery replacement may be a lot of hassle. (When expected battery lifetime exceeds expected equipment lifetime, it's tempting to just solder the battery in.) Things like semiconductor lasers in CD players are being operated "hard and hot"; this aggravates failure mechanisms like material migration and solid diffusion. Often there is a deliberate tradeoff between power output and lifetime, as with incandescent bulbs. For example, stadium lighting is often run at higher-than-normal voltages; the bulbs burn out quickly but yield a lot more light meanwhile, and this is a reasonable tradeoff in that application. Similarly, commercial semiconductor lasers have very limited power outputs because of difficult technical problems. Getting the necessary power with available components may *require* some deliberate loss of lifetime. Even when higher-power components really are available, it may be a good deal cheaper to opt for shorter life. (Just how much extra are most consumers willing to pay for long-life components? Regular incandescent bulbs heavily outsell long-life bulbs, remember.) > This troubles me. I had thought that we had a reasonable progression of > development of electronics during these days of solid-state gear > replacing tube equipment that meant longer life for any device. ... Longer, yes. But not infinite. Not even the phone company's highly conservative, heavily over-engineered equipment is expected to last more than 40-50 years (and this is *not* a zero-maintenance lifetime, either). > But now I see that designers either deliberately build in inevitable > failures (the use of volatile ROMs and batteries instead of PROMs or > other permanent devices) or the solid-state stuff I was led to believe > had indefinitely-long lives really is as short-lived as vacuum tubes > (the laser diodes mentioned above). You pays your money and you takes your choice. If you are willing to pay double or triple current prices, you could probably get some very long-lived equipment. (The high cost of military electronics is not *all* corruption and overcharging.) (95%, maybe.) > I may be insane, but I really expect electronic equipment to operate > forever. I don't want to buy any that has built-in and inevitable > failure. ... > I realize that consumer products have built-in planned obsolescence. > I'm not talking about small appliances, which I expect to die and be > replaced. I'm talking about multi-hundred-dollar equipment. Am I > totally unjustified in expecting such things to be designed to > continue to work indefinitely without maintenance, except for > mechanical stuff like motors, belts, pots, etc? Basically, yes. There ain't no way to make it work indefinitely. And making it work "a long time" is quite expensive. Semiconductors have made it relatively easy to build gear with far longer lifetimes than tube equipment, but this is a (large) quantitative improvement rather than a fundamental repeal of the Second Law of Thermodynamics. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
hoffman@pitt.UUCP (Bob Hoffman) (06/19/85)
Judging from the direction this discussion has been taking, I think
the point of the original note was lost. I don't think any of us
object to batteries being used in radios and the like to store
transient information. What's being objected to here is the use
of a battery-powered CMOS RAM _i_n_ _p_l_a_c_e_ _o_f a ROM for storing
the "permanent" part of the controller's memory.
In particular, Icom markets a series of radios with this sort of device.
The IC-R71A receiver, the IC-751 HF transceiver, the IC-271 144 MHz
transceiver, and the IC-471 440 MHz transceiver all use a
microprocessor based controller. Each radio, of course, has different
operating parameters, such as frequency range, modes, etc. Therefore,
the operating system must be different for each microprocessor. Now,
rather than using a ROM to store the operating system, they chose to
use a CMOS RAM backed up by a lithium battery.
If the battery should become disconnected, or if it should go dead
(claimed life: 6-7 years), the RAM loses its contents, and the radio
becomes completely useless. Unlike older receivers that used a
tuning capacitor to adjust the local oscillator frequency, it is now
done digitally with a voltage-controlled-oscillator and a digital
counter in a feedback loop. Without the microprocessor running, the
digital counter no longer works and the radio ceases to function.
Completely. As one person mentioned earlier, it becomes a ~$700
doorstop. The only repair is to send the radio (maybe just the RAM
module, I'm not sure) back to Icom to have the battery replaced and
the RAM reloaded.
What will happen when Icom decides to discontinue support for this line
of radios? I tend to keep my radios a long time. I dread the thought
of being helpless to prevent these units from failing.
If I were more adventurous, I would build a circuit to dump the contents
of the RAM into my computer and save the result on disk. Then, I could
either reprogram the RAM myself, or burn some ROMs to replace the whole
module.
What could have been Icom's motivation for doing this? Are they really
out to screw the public by making the radios obsolete before their time?
Could it be cheaper to manufacture this RAM module than a similar ROM?
Do I sound bitter? You bet. I own an R71A and a 271H and I think they're
excellent radios. Really first class. Except for their built-in
obsolescense. I had planned on getting a 471 next year, but am now
reconsidering.
Tnx for reading & 73,
--
Bob Hoffman, N3CVL {allegra, bellcore, cadre, idis, psuvax1}!pitt!hoffman
Pitt Computer Science hoffman%pitt@csnet-relayphil@amdcad.UUCP (Phil Ngai) (06/22/85)
In article <1005@pitt.UUCP> hoffman@pitt.UUCP (Bob Hoffman) writes: > What's being objected to here is the use >of a battery-powered CMOS RAM _i_n_ _p_l_a_c_e_ _o_f a ROM for storing >the "permanent" part of the controller's memory. This sounds very strange to me. Even if you are afraid of making a mistake and want to avoid using ROMs, EPROMs are dirt cheap ($2). The battery and CMOS RAM are probably more than this. So what reason could there be for using RAM? By the way, please don't be so clever with your ^H_s. -- Offensive pickup line follows: "Hi there, want to be my boy toy?" Phil Ngai (408) 749-5720 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA
ron@wjvax.UUCP (Ron Christian) (06/24/85)
>This sounds very strange to me. Even if you are afraid of making a mistake >and want to avoid using ROMs, EPROMs are dirt cheap ($2). The battery and >CMOS RAM are probably more than this. So what reason could there be for >using RAM? > > Phil Ngai (408) 749-5720 *** The only possible reason I can think of is, since the microprocessor probably needs RAM for scratch pad and storing of transient parameters, it may be cheaper to include one RAM for BOTH this and the microprocessor program. I can imagine some 'clever' engineer realizing he could eliminate one whole component and a bit of board space if he combines the RAM and ROM functions into a single IC. Plus, he suddenly has the built-in feature of nonvolitile user-settable parameters, since he has to battery back-up the ram anyway. 'Nifty!' he says to himself. This kind of engineer should be drowned at birth. BTW, I bet if you're very careful, you could replace the battery yourself without killing the ram. I for one wouldn't want to try it. Then again, I probably would not buy such a product in the first place. -- __ Ron Christian (Watkins-Johnson Co. San Jose, Calif.) {pesnta,twg,ios,qubix,turtlevax,tymix,vecpyr,certes,isi}!wjvax!ron
dhk@hp-pcd.UUCP (dhk) (06/28/85)
> > . . . if you're very careful, you could replace the battery yourself > without killing the RAM. I for one wouldn't want to try it. Then again, > I probably would not buy such a product in the first place. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Ron Christian (Watkins-Johnson Co. San Jose, Calif.) > The question is: "How do you know when you buy a product whether it has battery-backed RAM, in the first place?"
ron@wjvax.UUCP (Ron Christian) (07/02/85)
>> . . . if you're very careful, you could replace the battery yourself >> without killing the RAM. I for one wouldn't want to try it. Then again, >> I probably would not buy such a product in the first place. >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> Ron Christian (Watkins-Johnson Co. San Jose, Calif.) > >The question is: "How do you know when you buy a product whether it has >battery-backed RAM, in the first place?" *** You read the net, of course. (1/2 :-) Seriously, this is a good question. I guess you try to benifit from other's mistakes whenever possible. When the price of a product reaches the level where you subjectivly decide it's expensive, you try to find out whatever you can about it before laying down cash. When you find that in spite of your best efforts you've bought something with such a bone-headed 'feature' as this one, you quietly try to unload it at minimum loss. That's the only advice I can offer. Actually, I've been known to pry the back off electronic equipment before I buy it. Found a battery in a synthesizer I was about to buy, but further investigation proved it only kept the user settable parameters alive. No big deal. __ Ron Christian (me again) (Watkins-Johnson Co. San Jose, Calif.) {pesnta,twg,ios,qubix,turtlevax,tymix,vecpyr,certes,isi}!wjvax!ron -- __ Ron Christian (Watkins-Johnson Co. San Jose, Calif.) {pesnta,twg,ios,qubix,turtlevax,tymix,vecpyr,certes,isi}!wjvax!ron