At 18:46 11/20/98 +0000, you wrote:
>> >We all make mistakes (or at least I do :-)). It is worth checking this.
>> >Why DEC didn't use polarised connectors here is a mystery to me...
>>
>> This is indeed a bone-headed thing DEC did. I bet a lot of field engineers
>> were cussing about that. Must have been two different design departments
>> between RK's and RL's (Allison. . . comments?)
>
>The RL ribbon cable (from the RL11->bulkhead) can also be plugged in
>backwards. At least the 'fault' lamp comes on if you do that, though...
>
>> >IIRC, the RK07 spin-up is something like : Motor up to speed, brush cycle
>> >(old drives only), positioner unlocks and moves to outer guard band,
>> >postioner moves to spindle and back to track 0. Does yours do that?
>>
>> Seems right recalling the several times I've watched this process on the
>> RK. I'll check for sure. Track 0 is at the outer edge I assume?
>
>Yes. On every DEC drive I own (and I guess most others), track 0 is at
>the outside edge of the disk and the highest track is closest to the
I thought I should verify this. Seems sometimes when I assume something it
turns out wrong.
>spindle. Allison/Tim will now post a list of exceptions :-)
>
>
>> >Hmmm.. The positioner would be on track 0 after a spinup, and the
>> >standard boot is to read track 0, sector 0 into memory
>> >and jump to the start of it. So you might not see any head movement if
>> >there's nothing bootable on the pack.
>>
>> I see. Of course with absolutely no prior knowledge of such details as this
>> I am completely oblivious to what should be what. Now is the time to learn.
>
>No sure. And please don't think any of my messages are flames for lack of
>knowledge (even if I write them late at night when I am not as awake as I
>should be). _I_ had to learn all this stuff once, and I didn't have this
>great list to turn to.
I certainly don't think any of your msgs are flames for ignorance as I know
you are the type who is willing to share his knowledge and teach others.
You did not get to the level you are simply by getting a book or two and
dumping it into your head :) It's experience in the good old School of
Hard Knocks, just like me (and I'm getting knocked about a little here:) )
>
>
>> This is the first day ever of me even operating an 11/34A. I'll have to
>> figure out from the rather terse instructions in the user's manual how to
>> find and examine registers. At least the Programmers Console has a variety
>> of good features for this.
>
>
>Remember that on the PDP11, all I/O registers are just memory locations.
>Halt the processor after the failed boot attempt, key in the first
>address of the RK611 (I can't remember it, but you have the RK07 user
>manual, don't you?) and then press Load Addr. Then press Examine
>repeatedly and write down the octal numbers in the display. Convert to
>binary and figure out what the bits mean from the user manual.
>
>A couple of things to watch for. If you get a Bus Err on the first
>'examine' then check you typed the address in right. If you did, then for
>some reason the RK611 is not responding to the correct address.
>
>If the Error bit is set in the appropriate RK611 register, then decoding
>the other bits will give you a lot of info as to what happened.
Thanks for the tips Tony!
I think I may get some time next week to get back to this project.
Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt_at_netsync.net
Member of Antique Wireless Association
URL:
http://www.ggw.org/freenet/a/awa/
Received on Fri Nov 20 1998 - 21:24:00 GMT