Hi Barry,
That's great! While you searched and found that PIC a did some test here, now they are kind of moot but since I did them I'll post the results anyway.

The subroutine code, as written originally takes, 769 cycles (on an 18F part, don't know if it'll be any different on a 16F1x) including the GOSUB and RETURN. At 32MHz that's ~100us.

I thought that was quite a bit to tell you the truth so I tried replacing the array indexing FOR-NEXT loop discrete lines (Counter[0] = Counter[0] + Result.BIT0 and so on) and it went down from 769 to 87(!) cycles. 87 cycles at 32MHz is only ~11us.

The tricky part would obviosuly be to update the LCD during the duration of the test. I think you'd need to write a single character to LCD, GOSUB the test routine write another character, GOSUB the test routine and so on. Obviously not rewriting static information every time.

Anyway, if you've found a suitable device then going the interrupt route is probably better!

/Henrik.