Northstar Woe is NOT Me

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Mon May 24 07:30:20 1999

On Sun, 23 May 1999, Anthony Clifton - Wirehead wrote:

>
> Apparently the Northstar needed a break. I turned it off for about
> 10 minutes, powered it back on and *poof* now it boots! What gives?

It may be that one of the many 5V regulators got too hot and shut down.
Only was is to test with a meter if it happens again.

> I'm not used to this "subtle shades of grey" thing. I'm used to
> machines that either work or don't. This "I'm gonna freak out
> and then be ok in a few minutes" thing is just weird to me.

Compared to an Altair the NS was a walk in the park!

> Frankly, I'm starting to wonder how long it really takes for
> the voltage levels to drop low enough for things to be 'reset'.

Actually very short time for reset and the hardware reset on the back is
quite literally hardware reset. But beware of the 8V CD bus as that takes
a good 1-3 minutes to drop to near zero and inserting or removing a board
too soon after power off can be very BAD.

Despite 21 years with my first NS* the second one has proven a bit weird
as well. it took a bus terminator from my CCS system to take it down.
The only difference is the old system on average always had at least 5
boards plgged in and the current one only three.

If you want to try terminating the bus use this combo...

        330ohms between the +5 and the signal line and a 220 ohm between
        ground and the signal line.

        That will terminate the bus so there is less noise and also it wil
        assure a "open" line has a logic 1 (of about 3V).

        Terminate all teh control lines (10-15 of them), data in and data
        out. No need to do all 92 lines (some are gound, power or
        unused). Also many signals are unimplmented like the interrupt
        lines to the cpu.

One last source of problems on most any old machine is if cheap sockets
were used. Some of the RN sockets were just plain crap. I had trouble
with sockets back in summer of 79 after a lightening hit and many ICs
replaced and eventually had to pull ALL the sockets and solder teh chips
downn. It's been solid since.

Allison
Received on Mon May 24 1999 - 07:30:20 BST