17 Oct
1998
17 Oct
'98
2:36 p.m.
To further complicate matters, within digital the CPU
is identified
differently based on whether it has PMI memory installed or not.
(And, of course, it matters whether the PMI comes before or after
the CPU in the backplane!) So, for example, you may find a 18 MHz
CPU with non-PMI memory called a 11/73, but with PMI memory it's called
a 11/83.
In fact... you could find the system with PMI memory, but installed
in the wrong place, and it will be identifed - by software - as an
11/73B. If you put the same memory in the right place, it will be
identified as an 11/83.
If, indeed, you have the 11/84 capable version,
you'll also need the
KDJ11-B and the 11/84 backplane, along with PMI memory, to have a
real 11/84 CPU.
But the board with Qbus memory in the qbus of an 11/84 system box
should work...
I've also taken one of the KDJ11-B 18mhz boards, removed the 18mhz
clock and replaced it with a 20mhz clock... the boot ROM correctly
identifies the clock speed, and the system runs rock solid...
be warned - not all boards will do so, from what I understand...
your milage may vary... etc... If you make the change and it doesn't
work, don't blame me... (save the old clock).
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
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