Quantum DLT 2500, Product Manual

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DLT2000/DLT2700 Cartridge Tape Subsystem D-1
Appendix D
EEROM Resident Bugcheck and Event
Logs
D.1 EEROM Packets (Last n Error Events)
The DLT2000 products keep certain error and event logs in semi-permanent non-
volatile memory (EEROM) on the ECM. There is room for a total of 14 such
information packets in EEROM, each consisting of 98 bytes (96 data bytes plus 2
control bytes) of information. Packets can be written for many different reasons, and
several packet types exist, but each must conform to the standard EEROM LOG
packet envelope as shown in Figure D-1.
The information logs are maintained as a circular buffer; a new entry will overwrite
the oldest existing entry. At any point in time, the most recent 14 logs are kept.
The EEROM information packets can be retrieved by Log Sense command with page
code 07h ((Last n Error Events page).
The packet type field defines the content as well as the format of the data portion of
the packet (refer to Table D-1). These packet types are further delineated in the
sections that follow. Please note that the byte offsets in the structure layout diagrams
that follow are referenced relative to the beginning of the 98 byte EEROM Log
envelope.