Dear Mrs. Melanie - Ohhhh... don't marry me off yet... I'm still a Miss Melanie! Thank you for the compliments.

I don't recall giving advice about putting a Capacitor anywhere... perhaps it was Bruce. The Card-Detect is usually accomplished by either a photocell or a microswitch. Some cheap readers have the sensor positioned in front of the Read-Head so a card is detected as soon as it is inserted into the slot, but as it is swiped it is still travelling past the Read-Head as it clears the sensor therefore giving too early a warning that the card has been removed, so spoiling the read. A Capacitor could then be inserted to delay the card-detect signal... perhaps that was the reason, otherwise I just can't remember what it was for.

Anyhow, if you're only at the start of your project, I wouldn't worry about it until you meet any problem.

If you are going to read more than one track at the same time, then you will need either more PICs - one for each track, or a different PIC, as I recall (remember this was THREE YEARS AGO in 2002) the 16F84 pretty much maxed out on that RAM Buffer, and the 16F628 was only a bit better. You should be able to do it in one PIC, but will need to chose one with a lot more RAM and depending on how many tracks, you might need a speed increase beyond 4MHz.

Best wishes on your project in trying to make the world's smallest reader - Have fun.