RC11 manuals / schematics online?

Paul Koning paulkoning at comcast.net
Sat Jun 10 21:44:21 CDT 2017

> On Jun 10, 2017, at 10:35 PM, Paul Koning via cctalk <cctalk at classiccmp.org> wrote:
>> On Jun 10, 2017, at 4:59 PM, Mattis Lind via cctalk <cctalk at classiccmp.org> wrote:
>>> ...
>> BTW. Speaking of dumping. Now that I have a TC11 / TU56 that seems to be
>> working, what is the best way to dump 18 and 12 bit tapes? Is there some
>> PDP-11 OS that can do it or is it assembly programming required? I had
>> hopes that RT11 had such features but it doesn't seem like it could read
>> all 18 bits.
>> Has this already been done? Maybe I can spend time on other things than
>> re-inventing the wheel...
> RT-11 FILEX can read TOPS-10 format DECtapes.  I don't remember if it does PDP-8 DECtapes, that's a bit harder because the block size is different.
> If you want a raw block by block dump, I don't know about tools for that, though a look at the FILEX source code should give you some ideas.  Or the tape formatter code, for that matter; the basic idea is to put the RALL function to work.

By the way, in RALL mode you're using program I/O to read the 18 bits, so (a) that pretty much calls for assembly language, and (b) you have to talk directly to the device and block other interrupts or you'll lose data.  FILEX raises IPL to 6 or 7 to turn off all interrupts including the clock, if I remember correctly.


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