DECtape reliability?

Paul Koning paulkoning at comcast.net
Thu Nov 12 15:42:39 CST 2015


> On Nov 12, 2015, at 4:29 PM, Johnny Billquist <bqt at Update.UU.SE> wrote:
> 
> On 2015-11-12 19:49, Al Kossow wrote:
>> 
>> 
>> On 11/12/15 7:27 AM, Jon Elson wrote:
>> 
>>> LINCtape is essentially identical to DECtape.  I think the directory
>>> format is different, but I think the block format is the same.  I think
>>> the tapes are wound in reverse order and the order of increasing block
>>> numbers is reversed.
>>> 
>> 
>> Actually the block format is different. "Obverse Compliment" encoding
>> was created for DECtape. LINCtape blocks aren't bidirectional.
> 
> Aha. Interesting. I didn't know that the bit patterns of the control channel was different.
> 
> Curious question then - could most DECtape controllers even read LINCtpae?
> 
> I know the TD8E can. The most stupid controller on the planet, but it enables you to deal with just about any DECtape format you could possibly ever invent.
> 
> But other DECtape controllers might not be able to deal with tapes that use other codes to indicate what is being read...?

I believe you can do this on the TC11 with the READ-ALL operation, but my memory is vague and the manuals I have handy aren't detailed enough. 

	paul




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