Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Paul Winalski via cctalk 
On 10/16/18, William Pechter  wrote:
> DEC Tape II was the serial driven TU58.
> The TK50 was CompacTape or something like that.  It was the predecessor of a
> number of square tapes...
>
> See DLT on Wikipedia https://en.m.wikipedia.org/wiki/Digital_Linear_Tape
>
My mistake.  Yes, I was thinking of the TU58, a most miserable device.

-Paul W.

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Paul Winalski via cctalk 
On 10/15/18, Clem Cole  wrote:
> #$%^ - they >>weren't<< like DECtape from a reliability standpoint ...
> ᐧ
The original DECtape was extremely reliable.  Not so the TK50.
Calling it "DECtape II" was an insult to the original DECtape.  The
problem wasn't so much the drive itself, but the controller.  In an
effort to reduce costs, DEC used a controller that had insufficient
buffering capability for a streaming, block-replacement tape device
such as the TK50.  TK50s were prone to both data-late and overrun
errors.

The block size is almost certainly 512 bytes.

-Paul W.