jdm2 circuit
Hi,
Yes, its just the four lines to program most chips, but its how those lines are controlled that is very important.
Mclre and VDD must come on in certain ways and the speed, rise time, of these 2 rails is also important.
If you want to look into the heavy subject of programming chips go to Microchips site and seach with this phrase ' Programming Specification icsp '
You will be able to see plenty of info, but think you will be dissapointed because as you will see each type of chips has there own strict method of programing its memory.
There is no single universal method in that sense - hence why the 'hardware' of programmers are not so important, its there ability to be controlled by software that is.
With the Microchip range of Pic chips for the average diy enthusiast the Pickit2 is the best unit as it from microchip and its software is regularly maintained and updated with new devices and occasionally new functions like the Logic Analizer.