Tom wrote:
Not parity. 3480 is 18 tracks. That's 16 data bits and two parity bits.
Although 8 bit bytes are represented by 9 bit patterns,
data bytes are recorded in frames, that are grouped into clusters.
4 tracks are reserved for redundancy check bytes.
Up to 14 tracks contain data bytes,
On Sat, 28 Apr 2007 20:55:31 -0400, John S. Giltner, Jr. wrote:
I wonder if the differnce of 32K and 38K is user data vs user data
+parity.
Not parity. 3480 is 18 tracks. That's 16 data bits and two parity bits.
--
Tom Marchant
I have these comments in my REXX TAPESTAK program:
/* */
/* Add in the Inter Block Gaps (IBG) */
/* */
/* The density of a 3480 cartrige
R.S. wrote:
Robert Pelletier wrote:
Hi All. Question. Would anyone know the BPI of a 3480 cart running on
3480E drive (mock 3490). We have a request from a user to send us a
38,000 bpi cart. I swear they are 6250 bpi. Can anyone clear this up for
me? Where are they getting the 38,000? Thanks
Rich Smrcina wrote:
So are you saying that Ditto lies?
I already said what I'm saying. Few numbers simple math. I believe I
didn't make any mistake in my computations, and the numbers I used are
correct (*). Aren't that ?
If you ask about DITTO - well in my understanding DITTO has no idea
If you ask about DITTO - well in my understanding DITTO has no idea
about real BPI. How DITTO can measure length of the tape and number of
bytes written, especially when compression is turned on? Can DITTO
access number of metres of tape rewound from any counter in the drive?
I can be wrong,
On 29 Apr 2007 08:29:05 -0700, in bit.listserv.ibm-main you wrote:
If you ask about DITTO - well in my understanding DITTO has no idea
about real BPI. How DITTO can measure length of the tape and number of
bytes written, especially when compression is turned on? Can DITTO
access number of
In [EMAIL PROTECTED], on 04/28/2007
at 07:24 PM, R.S. [EMAIL PROTECTED] said:
Back to the question: CST cartridge contains 160m of tape.
Uncompressed capacity in 36-track drive (3490E) is 400MB.
So 400MB/160m gives 25000 B/cm Inch is 2.54 cm, so the BPI is 63500.
CST in 3480 drive has 31750
In [EMAIL PROTECTED], on 04/28/2007
at 08:55 PM, John S. Giltner, Jr. [EMAIL PROTECTED] said:
I wonder if the differnce of 32K and 38K is user data vs user data
+parity.
I have yet to see a product description in which the values given were
anything but the physical density. If you want
R.S. said:
It rather cannot be 38000.
If looking for an exact number, I think this is correct. But not for the
reason
described.
According to the ECMA standard, due to the ECC bytes (etc.) the maximum
density of data bytes is ...1,491 bytes per mm
= 37,871.4 BPI
If the maximum is 37,871,
So are you saying that Ditto lies?
R.S. wrote:
Robert Pelletier wrote:
Hi All. Question. Would anyone know the BPI of a 3480 cart running on
3480E drive (mock 3490). We have a request from a user to send us a
38,000 bpi cart. I swear they are 6250 bpi. Can anyone clear this up for
me? Where
I found a few references to some 3490E talking about the recording
density of 37,871 BPI
http://www.sunstarco.com/Tape%20Drives/Overland%20Data/Overland%20Data%20tapexpress_l490e.htm
http://www.archives.gov/records-mgmt/initiatives/transfer-regulation.html
Hi All. Question. Would anyone know the BPI of a 3480 cart running on
3480E drive (mock 3490). We have a request from a user to send us a
38,000 bpi cart. I swear they are 6250 bpi. Can anyone clear this up for
me? Where are they getting the 38,000? Thanks once again all.
Have a Nice Day !
6250 was 3420. The 3480 is 38K. Use DITTO to print the header and it
will show you.
Robert Pelletier wrote:
Hi All. Question. Would anyone know the BPI of a 3480 cart running on
3480E drive (mock 3490). We have a request from a user to send us a
38,000 bpi cart. I swear they are 6250 bpi.
/3490 Cart BPI
Hi All. Question. Would anyone know the BPI of a 3480 cart running on
3480E drive (mock 3490). We have a request from a user to send us a
38,000 bpi cart. I swear they are 6250 bpi. Can anyone clear this up for
me? Where are they getting the 38,000? Thanks once again all.
Have
Thanks I am DITTOing it as we speak.
Have a Nice Day !
Bob Pelletier
Connecticut Student Loan Foundation
Rocky Hill, Ct.
-Original Message-
From: Pommier, Rex R. [mailto:[EMAIL PROTECTED]
Sent: Friday, April 27, 2007 12:15 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: 3480/3490 Cart BPI
, Ct.
-Original Message-
From: Robert Pelletier
Sent: Friday, April 27, 2007 12:21 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: 3480/3490 Cart BPI
Thanks I am DITTOing it as we speak.
Have a Nice Day !
Bob Pelletier
Connecticut Student Loan Foundation
Rocky Hill, Ct.
-Original
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