> I was under the impression that in-circuit programming was LVP (low
> voltage programming).  Is that not the case?  Even so, ICSP uses some
> pins that cannot be used for I/O and I have already done projects where
> I needed every available I/O pin.  So I need a programmer with high
> voltage programming.  What I'm hoping is to be able to get one that does
> both instead of having to get two programmers.
>   
Your impressions are rather wrong

Pics are always programmed serially. Whether they are sitting in a 
target circuit or a socket dedicated to programming is generally 
irrelvent to the programmer circuit. Hardly any programmers use LVP, it 
wastes an IO pin on the target device and leaves a much greater 
possibility of the device going into program mode inadvertantly during 
normal operation. Really the only advantage of LVP is it saves on parts 
in the programmer.

There is no reason you can't use every IO line and program in circuit. 
Resistors can be added such that the programmer and pic can control the 
line during programming but the line can be used as an input or low 
power output when the circuit is in use. If you decide to disable MCLR 
programming gets a little tricker because the programmer needs to 
control VDD to get such chips into program mode but there are 
programmers that can control VDD and provide sufficiant current to drive 
a large target circuit (for example olin's proprog).


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