not sure this went out 11/45 status

Tony Duell ard at p850ug1.demon.co.uk
Tue Mar 1 17:38:40 CST 2005


> 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



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