Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-18 Thread Warner Losh via cctalk
On Thu, Oct 18, 2018 at 7:23 AM Paul Koning via cctalk < cctalk@classiccmp.org> wrote: > > > > On Oct 18, 2018, at 4:31 AM, Christian Corti via cctalk < > cctalk@classiccmp.org> wrote: > > > > On Wed, 17 Oct 2018, Clem Cole wrote: > >> As Paul W pointed out correctly, the TK50 and its children in

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-18 Thread Paul Koning via cctalk
> On Oct 18, 2018, at 4:31 AM, Christian Corti via cctalk > wrote: > > On Wed, 17 Oct 2018, Clem Cole wrote: >> As Paul W pointed out correctly, the TK50 and its children in the DLT* >> family all used a fixed format 512 byte *blocks on the tape*.This > > And that is wrong. The TK50

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-18 Thread Christian Corti via cctalk
On Wed, 17 Oct 2018, Clem Cole wrote: As Paul W pointed out correctly, the TK50 and its children in the DLT* family all used a fixed format 512 byte *blocks on the tape*.This And that is wrong. The TK50 clearly uses variable block sizes. For example, have a look at a RSX11 or VMS tape:

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-17 Thread Clem Cole via cctalk
I took most of this off line, but I'll try to close down the discussion, so we can get back to TUHS history. Please be careful of your wording as it is easy to get confused particularly if you never used the original 1/2" tape system you might not understand the actual terms. The term for

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-17 Thread Paul Koning via cctalk
> On Oct 17, 2018, at 10:50 AM, Ethan Dicks via cctalk > wrote: > > On Wed, Oct 17, 2018 at 8:15 AM emanuel stiebler via cctalk > wrote: >> there were >> TK50Z as an external drive, on "SCSI" > > I have one - for a MicroVAX 2000. I rarely used it. > >> TK50 on QBUS with an TQK50

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-17 Thread Ethan Dicks via cctalk
On Wed, Oct 17, 2018 at 8:15 AM emanuel stiebler via cctalk wrote: > there were > TK50Z as an external drive, on "SCSI" I have one - for a MicroVAX 2000. I rarely used it. > TK50 on QBUS with an TQK50 controller which really didn't stream to often We had one in the 1980s. You are right. It

TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

2018-10-17 Thread emanuel stiebler via cctalk
On 2018-10-16 20:37, Paul Koning via cctalk wrote: > > >> On Oct 16, 2018, at 1:23 PM, William Pechter via cctalk >> 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

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

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

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Clem Cole via cctalk
inalski > To: Clem Cole > Cc: The Eunuchs Hysterical Society , cctalk@classiccmp.org > Sent: Tue, 16 Oct 2018 13:14 > Subject: Re: [TUHS] Ultrix Tape: Block Size? > > On 10/15/18, Clem Cole wrote: > > #$%^ - they >>weren't<< like DECtape from a reliability

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Clem Cole via cctalk
On Tue, Oct 16, 2018 at 12:57 PM Paul Winalski wrote: > The block size is almost certainly 512 bytes. > Which is what I said - the block siize is set by the HW. But ... the issue is trying to get the TK-50 to stream. Hence the traditional unix: dd ibs=64K obs=XXX | tar xvfp - trick. This will

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Ethan Dicks via cctalk
On Tue, Oct 16, 2018 at 1:49 PM Paul Koning via cctalk wrote: > > On Oct 16, 2018, at 1:23 PM, William Pechter via cctalk > > 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... >

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread Paul Koning via cctalk
/en.m.wikipedia.org/wiki/Digital_Linear_Tape > > Bill > > -Original Message- > From: Paul Winalski > To: Clem Cole > Cc: The Eunuchs Hysterical Society , cctalk@classiccmp.org > Sent: Tue, 16 Oct 2018 13:14 > Subject: Re: [TUHS] Ultrix Tape: Block Size? > > On 10

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-16 Thread William Pechter via cctalk
: The Eunuchs Hysterical Society , cctalk@classiccmp.org Sent: Tue, 16 Oct 2018 13:14 Subject: Re: [TUHS] Ultrix Tape: Block Size? On 10/15/18, Clem Cole wrote: > #$%^ - they >>weren't<< like DECtape from a reliability standpoint ... > ᐧ The original DECtape was extremely reliable

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-15 Thread Clem Cole via cctalk
#$%^ - they >>weren't<< like DECtape from a reliability standpoint ... ᐧ On Mon, Oct 15, 2018 at 5:00 PM Clem Cole wrote: > Be careful, TK-50 is different than 9-track. It's a streamer tape like > QIC, 4mm and 8mm. The blocking is done under the covers by the HW and the > blovk size if just

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-15 Thread Clem Cole via cctalk
Be careful, TK-50 is different than 9-track. It's a streamer tape like QIC, 4mm and 8mm. The blocking is done under the covers by the HW and the blovk size if just how a DMA is done. I recommend that you pre-fetch the read with dd or double-dd setting ibs=64k, obs=20b and conv=sync and pipe

Re: [TUHS] Ultrix Tape: Block Size?

2018-10-15 Thread Warner Losh via cctalk
I'm glad you corrected because when they worked, they were awesome. When they didn't, life had a lot of swearing in it... And when I was sysadmin for the MicroVAX II that had them, I swore like a sailor Warner On Mon, Oct 15, 2018 at 3:04 PM Clem Cole wrote: > #$%^ - they >>weren't<< like