1)What is the difference between the two WatchDog timers positives or negatives. Which one would you recommend.
1. PCA WatchTimer
2. WDTRST WatchDog


2)Is it true that FLashMagic only needs to interface to the following pins? Dose anyone know where i can purchase a FlashMagic cable that has a transceiver on it and all the necessary logic.
1. RST
2. PSEN
3. TXD
4. RXD
5. GND
6. VCC/+5.0V

3)Also, I am using the 668 as a standalone processor with no external ram or code. Will the microcontrol operate OK with EA floating ie NC.
4)The RST pin has 20uF CAP connected to +5.0V

1) the PCA watchdog is the original Intel kluge. I would never use it. It is probably there for compatibility only. Why not use it? it can be disabled.

2) why not install NoTouch and no pins are involved

3) NO. Nevel let !RA float BTW it is also Vpp so you need it a +5 to program

4) get a supervisor chip, the RC reset is never a good idea.

Erik