Byron,

I think I know the programmer you're talking about and it's *not*
intelligent (the smarts came out of a PC).  Control was through the PCs
Parallel Port.  I think it was published around 1984.

I built one and was *really* disappointed in it.  It never really worked
well (because it only took files in Intel format - and I was playing around
with Motorola parts at the time) and was *very* PC Dependant (this was about
the time of the PC/AT and the speeding up of the ISA bus) - It wouldn't
program properly on a PC running faster than 12 MHz (the PC's internal bus
delay was used as part of the programming requirements).  It also had a
bunch of jumpers to allow different parts (not all that intelligent at all).

This was also about the time I figured out that if Ciarcia published a
project that was only wire-wrapped (or pin-pin wired like the EPROM
programmer was) chances are it would be pretty flaky.  Anytime he presented
a design with an embedded card, it usually worked fine.  Actually, I think
he needed an EPROM programmer for a specific application and didn't want to
pay for a commercial one (and got an article out of it as well).

You could probably build an EPROM Programmer using a PIC, Variable Voltage
Supply, and a few counters.  But there are the issues of understanding:

1.  What is the host platform.
2.  What is the object file format.
3.  What is the device you want to program (and what are the programming Specs).

If you understand what you're going to be easy, it shouldn't be that hard.

Good Luck,

myke
>>
>> does anyone know where a really cheap eprom programmer can be
>> found....and I mean CHEAP...
>> I'm 17....in HighSchool...and have no job.....right now i have 1 dollar
>> to my name...
>> so 140 bucks for an eprom programmer is out of the question.....
>
>This is an instance where you seem to have more time than money.
>Typically to program an EPROM you need a programmable voltage source
>and it's helpful to have a good timer. Lastly you need a way to get
>the data from the file to the EPROM.
>
>A PIC can help with all these tasks:
>
>programmable voltage: Check out an article that Steve Ciarcia did for
>BYTE magazine (about 10 years ago) where he built an intelligent serial
>EPROM programmer. You may not want to use the whole circuit (you can)
>but the LM317 based programmable voltage generator is definitely the ticket.
>Presuming a high voltage power supply (17-25VDC) is available, the programmable
>voltage part can be built for less than $5. The PIC can then control the
>voltage.
>
>Timer: PIC's have real good timers for the 0.1ms pulses required with most
>algorithms.
>
>Data transfer: Most any PIC can be programmed to read data from the serial
>port. It is also possible to use the parallel port to transfer data.
>
>You can put one together for maybe $20 and a lot of effort.
>
>BAJ
>
>

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For my money, nothing handles as well as a rental car." - P.J. O'Rourke