Old EPROM questions again, EPROM Programmer

> >> Well I know I'm a lot more selective about my TV and movies than the > >> majority of people but are you trying to tell me that there's NOTHING

> >> watching on TV or movies? What do you have against women, beer and

Very different in the UK. Most of the stuff on the standard 5 channels is terrible, and from what I've seen, the digital/satellite/cable channels aren't much better. Serously, I'd much rather be using a soldering iron... They're actually quite interesting books. 'The Voice of the Crystal' is about making crystal radios using _no_ commercial electronic components at all. He makes his own coils (trivial), detector (using a similar design to the ones made 100 years ago), variable capacitor (suprisinging hard to make, acually), headphones (both magnetic and crystal, the latter using the peizo-electric element from a cigarette lighter), etc. 'Instruments of Amplification', IMHO is the more interesting book. He describes how to homebrew amplifying devices (not the circuits, which any of us could make). The 'microphonic relay' (electromagnets coupled to a carbon microphone-like thing), diode and triode valves (using filaments taken from light bulbs, in case you're wondering), transisotrs (point-contact ones using the crystal from a germanium diode, copper oxide ones made the hard way), and so on.

Now, to be honext, the devices are terrible. If you want a triode to use, go and buy am ECC83 / 12AX7. If you want a tranistor, go and get a 2N3904. It'll work a lot better, last a lot longer (his first home-made valves had filament lifetimes of a few minutes, his transistors broke down at a few volts), and be a lot cheaper.

But IMHO you'll lear a lot if you read said books, and even more if you try to repeat and improve on the designs. There's probably little point if you've already built at least one programmer, or a similar insturment of similar complexity. But if you haven't, then you should have a go. As I aid, you'll learn a lot, not just about EPROMs... I think the best way to sum it up is to quote from a book written nearly 100 years ago called 'Every Boy His Own Mechanic'. This chapter covers making a simple telephone system " For some years previous to 1914 the constructive instinct and ability inherent in many of us was almost snuffed out because most of the mechanical and electrical things we wished to possess were so cheap that they could be bought ready made. Often the prices quoted were actually below the cost to us of the raw materials, and so we came to think that constructive hobbies were a bit futile. Lots of those cheap things were amazingly good, but some where exasperatingly bad, and the bulk indifferent. Still, we bought the stuff, learned nothing from it, and clean missed all the solid satisfaction that lives for ever in building and contriving and creating Take the ready-made cheap telephone, for instance. How long did it take to get fed up with ringing and asking "are you there ?" Was it really worth the outlay of 15s to 45s? Frankly, no. Why? Because our purchase locked us out from all the subtle mysteries of an ever-wonderful instrument (simple though it may be), and we had been robbed of all the joy of its making. If it failed to act we discovered that we could not put it right. If it acted perfectly, we took the whole thing for granted and soon became bored. But to build up that same installation oneself in the face of difficulties from the homeliest of raw materials, and at last to have it (in litteral fact) voicing our triumph in our eager-listening ears - ah, that is a very different matter! " And that's why I still homebrew stuff....

-tony