Re: Date 2000 a problem for Apple II?

[mspaeth@athena.mit.edu (Mark C Spaeth)]

In article <63vmt8$idn$1@news.ece.nwu.edu>,
Paul Brazis <paulb@arcadia.ece.nwu.edu> wrote:
>One little question about this "year 2000" problem. Computers (last time I
>checked :) ) use base-16 numbers. So why doesn't the "two-digit" year read
>as 9A instead of 00? I remember some problems with some local BBS's back in
>Jan. 1990 with the date looking like 198! or something like that. So
>following this logic, why doens't the date look like 199! ?

Umm... hate to say it, but incredibly stupid question.  The year 2k problem
has to due with dates stored as ascii chars where the last 2 digits were used
for the date.  If the date were stored in a byte, 1999 would be 63, and 2000
would be 64.  What you're referring to is packed BCD, where 1999 would be
represented as hex 99, but 2000 could net be 9A, as A is not a valid bcd char.
In any case, it would probably be A0, not 9A, since A0 would represent a 
miscalculation in the carry to the next BCD digit, while 9A would mean a
screwed up half carry all along :)