Solder rot

[JonH]

Yes, and for products involved in the safety of the realm.

Regards JonH

[D.M. Procida]

What exactly was the problem with lead solder? Were children eating it or something?

Daniele

[John Williamson]

The Powers That Be decided that if electronics stuff containing lead was disposed by dumping it into landfill, the lead would leach out into the water supply or if it was burnt, the lead would be carried in the flue gases and spread itself all over the landscape.

[D.M. Procida]

... whereas it's really great for the environment for our society to dispose of mountains of prematurely-deceased tin-whiskered electronic junk.

Daniele

[John Williamson]

You noticed the shortcomings, then.

[Jules Richardson]

Yes, I've seen that too, particularly on 1970s and very early 1980's machines. In some cases they seem to rot from the inside-out, so visually the pins look OK but electrically and mechanically they're very weak (I remember needing to replace about half the ICs in one particular machine)

I've fixed a few Commodore PETs over the years, but didn't mess with the C64 so much - although I remember working on SX64s (which IIRC are much the same guts) and there was one particular custom IC which had a reputation for failing for no good reason.

Picture, too; my ZX80 was a right bastard when it came to getting any form of remotely modern TV to lock on to its signal.

In some cases, yes. The vast majority of faults I've found to be mechanical in nature - keyboard switches, connectors, IC sockets etc.

Occasionally a reset circuit will die, and memory faults are reasonably common.

I've lost count of how many times I've seen one of the noise surpession capacitors on the mains side of a PSU let go with clouds of smoke, though.

cheers

Jules

[Terry Casey]

Another inside-out phenomenon - and a dire warning of what to expect in the future with all the electronics built with lead free solder - was the problem exhibited by Mullard/Philips AF11n range of transistors.

These had a fourth wire connected to the metal can for earthing purposes. Why, I don't know, because the previous OC4n range were in an unscreened glass enclosure and the later AF12n range didn't have an earth wire.

However, the problem was that the AF11n range were built in tin plated metal cans. The tin grows whiskers - literally hundreds of the things - until, eventually, one of them contacts the transistor assembly itself and stops it dead.

An excellent set of slides from a NASA investigation of the problem can be seen at:

[The Natural Philosopher]

Isn't it better to get one of those emulator things and run the games under that?

a pentium running a Z80 simulator is still faster than a z-80 :-)

[John Rumm]

Quite often lead free in Europe, although it can be tricky on military stuff where you have US manufactured primary parts (or second source - as is usually a requirement) - since they will often come pre-tinned with leaded solder.

Its still readily available anyway since its needed for repair work on existing equipment. CPC do it.

[John Rumm]

Dead 5481 SID chip possibly... (plenty on eBay, for a price!)

[D.M. Procida]

It depends what you want it for. The real thing seems more fun to me.

Daniele

[Brian Gaff]

Yes the Comode actually runs a derivitive of the 6502 with a number of custom chips for sound and graphics. They were fun and even had pretty good built in basic, though I preferred the Sinclair for that. I have an Atari here and wondered if it might still work. Not for me, but if anyone wants it to try, they are welcome to it as it has all the bits, disc drive, tape deck and printer interface. 8 bit with some carts and software but of course not run up for a loooong time so may not work. the leads are custom pludgged though and the psus are here but which is which? 800 xl. Brian

[Tim Streater]

I think in the end I found the Z80 to be too irritating. An extra set of the main registers, yes, that's handy. But those IX and IY regs, more or less useless.

[Bob Eager]

Not if you're a compiler writer. I remember making extensive use of them.

[Frank Erskine]

Neither Maplin nor B&Q do now, though.

[Bob Eager]

Rapid did when I last looked.

[geoff]

In message , Frank Erskine writes

That reminds me - Ive only got 24 500 reels left - time I bought some more

[Huge]

The last (and only) compiler I worked on compiled ESPL/1 for the ITT3200. It was written in ESPL/1, so I have no idea what the underlying architecture of the machine was. In my defence, it was nearly 40 years ago.

[Tim Streater]

Hmmm, I never wrote much for the Z80 in the end, although I did do a cross-assembler (in BCPL) for it while at CERN. Sad to say I don't have the source and neither does CERN, any longer :-(

[grimly4]

That's ok, it all goes to Indian villages where the kids can earn a few rupees a day dismantling and burning it for the gold content. Everybody wins; except them, of course.