> When the unit is powered up, there is no output
to the terminal, and the
> processor fault LED's give a code of 14, which is listed as "Scope
Loop" -
does anyone
know what this signifies?
The original meaning of 'scope loop' in DEC diagnostics was a tight loop
that kept on accessing some failing piece of hardware so you could use a
non-storage 'scope to debug it.
I would assume, based on the fact it's code 14, that it's fairly early on
in the power-on diagnostics of your 11/23+ system, and that there's
smething fairly fuandamentally wrong with the CPU/memory/bus.
-tony
I got a little further with this today:
I put the machine back to it's original configuration, with all the cards
in, and returned the DIP switches to their original position. The machine
then runs through its POST, and tries to boot from the network (alternatly
off the two cards!), and is happy to sit there in that position.
After asking around, I found a copy of the standalone test instruction for
the 11/23's on this system (there were around 50 between the main system and
the test one). This gave instructions for installing a disk controller
(RL02), and altering theCPU switches to get the system to boot from disk. I
tried this, but I can't get it to work - yet!
The interesting piece of information from the documents was, the CPU has
non-standard boot ROMs, so the DIP settings in the 11/23+ manual do not
apply - hence the machine fails with error code 14.
I will try to get the machine to run the existing RL02 boot, as this was
intended to allow you to run XXDP, and also RSX11 (there are some specialist
diagnostics written to run under RSX11, so if I can find the right disks, I
should have a ready built operating system!). If not, I believe there are
copies of the original boot ROMs available on the net.
Jim.
