Yapp! Mac
In the last years of the past millennium I was very attracted by the idea of controlling small circuits and self-made devices with computers, particularly with my PowerMac 7100. At the beginning it looked like a very difficult thing to do, since Macs lacked the straightforward parallel printer port available in ordinary PCs. However, after a bit of research, I managed to solve the issue: the PowerMac serial port proved to be perfectly compatible with the regular RS232 serial interface of every PCs. Correctly using the RS232 with its thin cable was also much more elegant than pulling 16 and more wires out of a PC parallel port.
So I needed something "intelligent" enough to translate 16 general TTL I/O lines to RS232 and viceversa, to cleanly control LEDs, motors and everything else using the Mac. My decision went to the PIC16F84 microcontroller: it looked simple and cheap enough. I also decided to build the PIC programmer myself, using a project by Sergio Tanzilli called Yapp! (yet another PIC programmer). This programmer was cool and "intelligent" (it used a PIC microcontroller itself) but it was controlled by a custom program written for DOS, so I used an awful 286 PC with just that program installed, just to program PICs. This solution was less than optimal in a number of ways.
It would have been nice to use the Yapp! programmer directly from the Mac. Since at the time I was also learning MacOS programming, I decided to join the two things and make my own Yapp! driver for the MacOS. Development took a bit of time but finally I had my own Mac PIC programmer, with a pretty graphical interface in MacOS style. You can find it here.
This version was written to be compatible with Yapp! firmware version 2.5.
Soon after the first release, Apple decided to drop the serial ports from every Mac in favor of the more modern USB. Though Yapp! Mac was tested with a USB-to-serial converter by someone (and it worked), the very Yapp! project was interrupted soon later and everything ended, including my interest on the subject and my support for Yapp! Mac.
I don't know if there are projects for USB PIC programmers around. Are PICs still in use?
Last update: 2007-12-28
