29 Mar
2018
29 Mar
'18
2:49 p.m.
J8 (position 0) is where the jumper already is on
both my 3000 600 machines.
It is possible that this is where it normally is, however, it is also possible
that I moved it there some time ago in an attempt to diagnose the problem and
I have since forgotten. Which position is the jumper at in your system?
It's in at position 0 (J8), as per documentation.
These must be the alternative diagnostic routines mentioned the system
programmer's manual:
"A DECchip 21064-AA CPU, including on-chip 8-KB instruction and 8-KB data
caches, and a 64-KB serial boot ROM. A 64-KB stream holds the primitive
boot code for booting the operating system. Jumpers provide for the
selection of up to seven other streams for diagnostic and other purposes.
(The entire UVPROM is 64 K x 8.)"
Yes. I didn't bother trying these jumpers earlier as not having description
of the the diagnostics, I thought their operation might be rather obscure.
Happily some of them at least are pretty simple and obvious.
I take it F0 is the last output from SROM before handing control over to
SRM. Now that you've got a way to see SROM diagnostic output directly I
would expect these codes not to matter as much anymore.
It appears I was confused. In chapter 14 of flspcsva, table 14-1 "Power-Up
Test Serial ROM Codes" seemingly applies to the DEC 3000 800 only, despite
being in the part III "Common System Information" section of the manual.
Regards,
Peter Coghlan.
Maciej