W dniu 2018-01-23 o 17:50, Anne & Lynn Wheeler pisze:
[email protected] (Christopher Y. Blaicher) writes:
Your right, things are a little confusing.
SECTORS - Think of it as 224 pieces of pie. It is, I believe, physical.
CELL - Also physical, but I think of them as little chunks of data,
which may be your data or control data for the hardware.
TRACK BALANCE - How much room is left on the track if you were to
write a single block. Look up TRKBAL macro.
That extra calculation is for device control information, part of
which I know is CRC, or at least that is what I was told. All that
stuff other than the COUNT-KEY-DATA areas are for the hardware and we
mortals can't see it, but it is there.
and all that is now archaic fiction since no real CKD have been made for
decades, being simulated on industry standard fixed-block
this is the "real" format ... giving both 512byte FBA and the newer
4096byte FBA
https://en.wikipedia.org/wiki/Advanced_Format
part of the change justification is 4096byte is more "efficient"
... 15byte "gap, sync, address mark" for each phsical record and "512"
has 50byte ECC and 4096 has 100byte ECC for each record (eight 512 has
400byte ECC total) ... 512byte efficiency 88.7% and 4096byte efficiency
97.3%
That's true, it is emulated now. However from MVS point of view there
are still HA, R0, C, K, D fields of records, etc. Even gaps are still
there and it seem also CRC code still occupy virtual data cells.
Regards
--
Radoslaw Skorupka
Lodz, Poland
======================================================================
--
Treść tej wiadomości może zawierać informacje prawnie chronione Banku
przeznaczone wyłącznie do użytku służbowego adresata. Odbiorcą może być jedynie
jej adresat z wyłączeniem dostępu osób trzecich. Jeżeli nie jesteś adresatem
niniejszej wiadomości lub pracownikiem upoważnionym do jej przekazania
adresatowi, informujemy, że jej rozpowszechnianie, kopiowanie, rozprowadzanie
lub inne działanie o podobnym charakterze jest prawnie zabronione i może być
karalne. Jeżeli otrzymałeś tę wiadomość omyłkowo, prosimy niezwłocznie
zawiadomić nadawcę wysyłając odpowiedź oraz trwale usunąć tę wiadomość
włączając w to wszelkie jej kopie wydrukowane lub zapisane na dysku.
This e-mail may contain legally privileged information of the Bank and is
intended solely for business use of the addressee. This e-mail may only be
received by the addressee and may not be disclosed to any third parties. If you
are not the intended addressee of this e-mail or the employee authorized to
forward it to the addressee, be advised that any dissemination, copying,
distribution or any other similar activity is legally prohibited and may be
punishable. If you received this e-mail by mistake please advise the sender
immediately by using the reply facility in your e-mail software and delete
permanently this e-mail including any copies of it either printed or saved to
hard drive.
mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa,
www.mBank.pl, e-mail: [email protected]ąd Rejonowy dla m. st. Warszawy XII
Wydział Gospodarczy Krajowego Rejestru Sądowego, nr rejestru przedsiębiorców
KRS 0000025237, NIP: 526-021-50-88. Według stanu na dzień 01.01.2018 r. kapitał
zakładowy mBanku S.A. (w całości wpłacony) wynosi 169.248.488 złotych.
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
