I need to randomly select a bit in a table. The table could
contain up to 100,000 bits. Held in program memory this
is 7143 ( = 1BE7)  14-bit bytes

I'd like some comments about various methods to do this,
bearing in mind I have the full resources of an F877 to use
as either seeds or PRNG, ie ADC, 8 and 16 bit timers, and
WDT

Some thoughts

(a) randomly select byte and then randomly select bit in byte

(b) go for the whole 1-100,000 range in one number

(c) use ADC on a sine or noise signal at non-synchronous
times as determined by WDT

(d) add 2 x timer1 values as determined by WDT or ADC value

Adding h/w such as white noise is less preferable to using internal
pseudo-randomness such as WDT

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body