Specifications

ATAPI For Streaming Tape QIC-157 Rev B

Table 6-47 Key for Density Codes

Code Meaning

NRZI Non Return to Zero, change on ones

GCR Group Code Recording

PE Phase Encoded

MFM Modified Frequency Modulation

IMFM Inverted MFM

FMFM Floppy compatible MFM

DDS DAT Data Storage

RLL Run Length Limited

R Reel-to-Reel

C Cartridge

CS Cassette

NOTES:

1. Serial Recorded.

2. Parallel Recorded.

3. Old format known as QIC-11.

4. See Appendix D for additional standards information.

5. Helical Scan

6. This is not an American National Standard. The reference is based on an industry standard

definition of the media format.

7. This density code value is defined for the MODE SELECT command and shall not be returned by

the MODE SENSE command.

6.8.8.55.Data Compression Page Code 0Fh

Table 6-48 Data Compression Page

Bit

Byte

7 6 5 4 3 2 1 0

0 PS Reserved Page Code (0Fh)

1 Page Length (0Eh)

2 DCE DCC Reserved

3 DDE RED Reserved

4 (MSB)

5 Compression Algorithm

7 (LSB)

8 (MSB)

9 Decompression Algorithm

11 (LSB)

12 Reserved

13 Reserved

14 Reserved

15 Reserved

This page specifies the parameters for the control of data compression in a Device.