dual 7-segment countdown timer code

[precision]

i've said that hundreds of time on many forums... they're good for lazy prototyping and/or in a well shielded enclosure. In harsh environment, they could (and sure they will) be a real pain in the... but on the flip side, it may work good... and maybe long enough to cover the warranty time

i NEVER use pull-up, never use the 'Set your pin as output and let'em floating in the air' The theory is hum hum good, but... will your design will always be powered? What happen with those pull-up when you remove the power... they're software enable after all!

Please explain what is the problem in pullup, if chip have pullup feature ?
i ever useing OUTPUT PORTB.0 , is this wrong way ? Please tell what we must...


.