[quote author="ian"]Sorry about the spam filter.[/quote] No problem. I understand it.
I've released a new version. The original one contained a bug that might have deteriorated serial communication robustness, so that one is fixed. But I've also added a second target, including pre-built binary: the ATtiny25. While it is of course nice to use the smallest AVR possible for the task, using 6 I/O pins on an 8-pin device means there have to be some compromises. The ATtiny25 is definitely not first choice when you're new to AVR's, because it is easy to screw up and waste an ATtiny25 during programming, and it also might be necessary to calibrate the internal oscillator if the factory calibration isn't good enough.
Oh, and I found a PIC16C84 and PIC16F84 in a box, so I also tested that those worked with the programmer. And yes, they did.
I came across basically the same problem as the topic starter, but for a different PIC. I needed to program a PIC16F630. I tried the serial port style programmer that Jaakko Hyvätti's Picprog is written for, but I couldn't get it to work. So I made a simple AVR program and a quick-and-dirty patch to Picprog to flash me a PIC16F630. I'm releasing the program under the GPLv3. The included README does suppose you are well versed in working with AVR's, avr-libc and avr-gcc. As an afterthought, I've tried to make it a little easier by including a firmware for an ATmega88 @ 20 MHz.
<edit> The firmware only uses one 8-bit timer and an external interrupt, all other functions are completely implemented in software. So it should be possible to run it on any AVR with enough memory and 6 I/O pins available. </edit>
I suspect the programmer might work for all PIC12 and PIC16 chips supported by Picprog, but I didn't investigate much.
I used a simple USB to serial converter with 5V logic lines. Don't connect the AVR straight to a serial port of your PC :).
I'm providing this as-is. It did it's job for me, I added some documentation and functionality in the hope that it is useful for other people. I don't intend to do any more work on it, but others are encouraged to add all the bells and whistles they want! :)
I submitted the ugly, ugly patch for Picprog to the author of that program. Perhaps he or someone else wants to add proper support for this programmer to it. Or something alike.
This is my first post, and as such I can't create links to my program or Picprog. In 24 hours or so, I will come back and post this again with URL's. <edit>Added URL's. But see next post for added content!</edit>