> Sorry I left out a key word in my drowsiness. Programmer. I need the device to
> program the chip. I can buy PIC16C84's for $6.50 each but I saw some
> programming units going for $3000. I have since started building one from the
> directions provided by Microchip. The article is on their web site, article
> an589. I estimate the cost of this project under $10. Thank you to all those
> that recommended it. What extra functionality am I missing out by not having
> the expensive programmer?

Expensive programmers generally have the following advantages over cheap
ones:

[1] Full conformance to Microchip specifications, including the use of a
    variable VDD supply.  Not too much of an issue for the '84, but very
    much an issue with UV-eraseable parts, especially if they'll be used
    in low-voltage applications.

[2] Nicer construction, typically; ZIF sockets.

[3] Ability to program a variety of parts (incl. 16C5x parts and EEPROMs)

[4] In some cases, easier ability to swap chips (e.g. not having to unplug
    power first).

[5] In some cases, the ability to program multiple chips simultaneously.

[6] In some cases, the ability to detect conditions such as incorrectly-
    inserted chips without damaging the chip in question.

[7] In some cases, easier upgrades when new chips come out (in other cases,
    much harder upgrades--why do people have to put so much #&$#$* "intel-
    ligence" into those things?