>NOT to beat a dead horse, but what are the power
>requirements so far and what is the expected
>power budget for any peripherals?

OK, here are the "power dissipating blocks" as I see the circuit.

1. Always present. 16F877(A) or 18F452 iPIC using 3.6MHz crystal.
Miscellaneous 74HC(T) chips. MAX202 and FTDI FT232 USB I/F. Some LED
indicators (about 4, of which probably only 2 on at any one time). Some low
power op amp and other linear circuit used by (2) or (3).

2. Often present. 16F877(A) or 18F452 Target 1 PIC, frequency controlled by
crystal, resonator or RC depending on user requirement. Outputs include 2 x
10 led bargraph (one run by LM3914, one digital drive), 1 x 4 digit 7
segment display with digits multiplexed.

3. Sometimes present. 16F877A or 18F452 target 2 PIC. Clock rate
possibilities as per (2). Minimal peripherals, but additional unknown chips
possibly fitted to breadboard area by end user.

Admittedly a 7805 may well handle these requirements, and I think that it
will be a case of trying a 7805 to see if it will handle the situation.
However I was planning to include the tracking for a switchmode on the
prototype board as an alternative at this stage.

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