Re: 74ls612, clocking 6502and others...

From: Marko Mäkelä (
Date: 1998-04-21 23:21:18

> Then explain me the $DE00/$DFFF trick of Marko :-)

Explain it to me too. :-)  By the way, a similar effect occurs also with
the 1541 and with the VIC-20.  Haven't you ever wondered why reading from
a non-existing address returns the page number, e.g. reading from $20xx
returns $20?  Could it by any means have anything to do with the fact that
the high-order byte of the address was on the data bus right before the
read operation? :-) But why does it work?  The VIC-20 and the 1541 have
static RAM, while the C64 and the C128 have dynamic RAM, so that is not
the explanation. 


Archive generated by hypermail 2.1.1.