>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 |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '_at_' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL:
http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
Received on Sat Oct 17 1998 - 21:36:49 BST