1 Mar
2005
1 Mar
'05
6:38 p.m.
2) My front panel has an oddity (to me). If I select
say address 10000 and
hit load addr the address lights respond correctly with 10000. I then hit
examine and get nothing (blank data lights). Whatever... but here's the
interesting part. If I keep pressing examine over and over again, the
address lights count up just like they should - except they skip bit zero
(the rightmost bit, either 0 or 15 whatever dec nomenclature is). I don't
DEC have 0 as the LSB (rightmost bit on the panel)
mean that the rightmost bit just isn't displaying
correctly, the actual
counting sequence acts like the rightmost bit is the 2nd light from the
right. I can tell it's not just a bulb problem because I don't have to hit
load addr twice to "move on", the count is smooth and sequential without the
rightmost bit. Any thoughts offhand?
YEs, it's working correctly. Remember that the address is actually a
_byte_ address (the LSB of the address selects the byte within the word
for byte operations). The front panel accesses a word (2 bytes) at a
time, the address is always even (LSB = 0) and increments by 2 after each
EXAMine or DEPosit.
-tony