Hi George, At 2004-05-06 20:24, George Mogiljansky wrote: >I found a note from 1995 that this chip was >once-programmable.
It depends on the characters behind 'MC68HC05', the so-called postfix, could you write them down. Among us we have a lot of Motorola-expertise and databooks etc. Please also tell us the production date on the chip, something like 9534 perhaps? Or give an indication how old the computer is. Most chips in a printed circuit board have a code like 9534, the first two digits are the year (95) and the last two digits are the week number (34). Just look at the dates of about five to ten chips and you'll know what date the printed circuit board was produced after. (And usually shortly after, because keeping unused stock costs money). Here are more tips about chip 'spotting': http://www.chipdir.info/spotting.htm >Also, Fatcity once hosted a mailing list dedicated to.. >"..Purpose: Developers, engineers and users of the >Motorola MC68HC05 family of devices can talk about the >chip, how to use it, share techniques, code, >schematics, discuss tools, etc.." I just tried to subscribe to it and I got back: >>>>> subscribe mc68hc05-L >No such mailing list is carried at this site. Use LISTS for assistance. The official Motorola 6805/08 has also gone it seems, because I just tried to subscribe and couldn't. Well, the 6805-mailing-list happened to be the reason why I asked Bruce Bergman of Fatcity.com to host this mailing list and I know that a lot of experts visiting the 6805/6808 lists now read this (and the 6811/6812) list. >So I hope it is flashable; I hope for you it's not. ;-) >but what are the chances of embedded code being >corrupted ? Flash has a certain lifespan and when your PC is from about 1995 (which I guess based on it's Mhz frequency) it's nearing it's 10 year lifespan. Reflashing could help, because the part isn't taking *real* damage but will have lost too much voltage level in each bit that bits will start to be read as ones instead of zeroes and the other way round, but these errors should occur all over the chip and not just in parts and when SCSI still works and works all of the time, that would be strange. BTW. Ancient flash memory can also wear down by reprogramming it too often (about 100k times in those days), but you clearly haven't done that. BTW2. In those days memory like this wasn't flash yet I think, but EEPROM. It might help to make the distinction when you are doing more research. In one-time programmable memory, fuses are blown up and it stays that way forever. That's why I hoped you'd have that. ;-) >By the way, I am in >touch with other owners who have similar problems. When it's a systematical problem it's probably the 10-year EEPROM issue. Reprogramming it would remedy that (for another 10 years). Have you asked Apple what to do about it? When they don't cooperate, I would search on the WWW to see if the problem has already been solved or otherwise try to get hold of a programmer for the 68HC05 that can do flash and read out a couple of 68HC05's to see if they all have the same code and perhaps bits that are different and then have software decide for each bit what it should be by majority rule and burn a new 68HC05 and see if it remedies the problems. >If anybody is interested, I will try to provide more >info, e.g. Open Firmware commands available for the >3400 PowerBook, developer's notes. Yes, that might help. By the way: 'Open Firmware' also provides a clue about it beeing flash... (Read on..) >George > >--- Uwe Zimmermann <[EMAIL PROTECTED]> wrote: >> Hello George, >> >> of course if should be possible to reflash a flash >> microcontroller, Unless it's protected, but usually it's read protected, so you can still overwrite the complete flash memory, but you can't read the old contents. >> If the 68HC05 (whatever it does in the PowerBook) is >> the cause of the >> trouble I would start looking for de-soldering of >> any of the contact legs! And first tell us if it's perhaps in a socket? (But socket problems usually start earlier.) (Read on..) >> GM> If the embedded PMU 68HC05 chip is the source of >> GM> problems (known-good internal HDD not being >> recognized and not booting Known good in the same kind of laptop? I'm not sure if modern HDD's are still backwards compatible... >> fan turning on and off; Is it temperature controlled? Can the sensor or it's circuit be faulty? >> using an external powered SCSI device eliminates all >> problems), This is what still makes me doubt blaming the flash code. >> GM> is it possible to reflash the chip ? >> GM> This is a 3400c/180 Mhz PowerBook. By the way, why not buy a new laptop? This one is quite old and prices have dropped a lot, at least in the non-Apple world. And other parts of the laptop may have given up by now or are likely to give up soon, like the batteries? Greetings, Jaap -- Author: Jaap van Ganswijk INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). 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