Z80 pod, passes the self test. Runs Ms. Pac but weirdly. 4.8 Vcc, couldn't
crank it any higher. Run UUT @ 0 reboots and runs the board through the self
test but then is flipped, has garbage, etc. Known good Pac board, runs fine
with a real Z80 in it.

So, is it something I'm doing wrong or possibly bad pod?

Just got the 9010a, so I don't know if that's bad unfortunately. Need to
find something to run the 6502 pod in...collecting preliminary
guesses/advice at this point.

--
"Quality is the enemy of production."
Homepage - http://members.cox.net/rcbullock/ 'It's lamer than Spaeth's!'
** Replies to rcbullock '"AT"" cox.net ** Sorry, I detest spam.

"Robert Bullock" wrote in message
news:0KBLd.13473$PB.973@okepread01...
Z80 pod, passes the self test. Runs Ms. Pac but weirdly. 4.8 Vcc, couldn't
crank it any higher. Run UUT @ 0 reboots and runs the board through the
self
test but then is flipped, has garbage, etc. Known good Pac board, runs
fine
with a real Z80 in it.


huh?

"Harvey" wrote in message
...

"Robert Bullock" wrote in message
news:0KBLd.13473$PB.973@okepread01...
Z80 pod, passes the self test. Runs Ms. Pac but weirdly. 4.8 Vcc,
couldn't
crank it any higher. Run UUT @ 0 reboots and runs the board through the
self
test but then is flipped, has garbage, etc. Known good Pac board, runs
fine
with a real Z80 in it.


huh?



What do you mean "huh"? I don't know the answer but his post is pretty
clear.

On Mon, 31 Jan 2005 20:22:52 -0600 "Robert Bullock"
wrote in Message id:
0KBLd.13473$PB.973@okepread01:

Z80 pod, passes the self test. Runs Ms. Pac but weirdly. 4.8 Vcc, couldn't
crank it any higher. Run UUT @ 0 reboots and runs the board through the self
test but then is flipped, has garbage, etc. Known good Pac board, runs fine
with a real Z80 in it.

So, is it something I'm doing wrong or possibly bad pod?

Just got the 9010a, so I don't know if that's bad unfortunately. Need to
find something to run the 6502 pod in...collecting preliminary
guesses/advice at this point.

Are your sure that the POD supports the clock speed that the UUT is
running at?

Have you used any of the built in tests like RAM TEST on your UUT?

At 4.8 volts you may want to see what's going on there with the power
supply, have you looked at the +5 with a scope?

I would find it much more likely that you have a marginal UUT, than a POD.
I've been using the 9010/9100 for almost 20 years with no problems. They
were built very well.

At 4.8 volts you may want to see what's going on there with the power
supply, have you looked at the +5 with a scope?



Pac boards use an onboard linear regulator, it's a fairly common trouble
spot, first thing to do is resolder everything suspect in that area, get
very close to 5v and go from there. It's surprising how intolerant some TTL
chips are to low or high supply voltage.

On Wed, 02 Feb 2005 04:48:01 GMT "James Sweet"
wrote in Message id: 5YYLd.2200$uc.1120@trnddc09:



At 4.8 volts you may want to see what's going on there with the power
supply, have you looked at the +5 with a scope?



Pac boards use an onboard linear regulator, it's a fairly common trouble
spot, first thing to do is resolder everything suspect in that area, get
very close to 5v and go from there. It's surprising how intolerant some TTL
chips are to low or high supply voltage.

I hadn't realized that with regards to the linear regulator. Could very
well be some failing electrolytic caps, causing a lot of ripple in the +5
rail. That would certainly explain a low reading if he were using a DMM
instead of a scope.