Figure 1-7, Preamp and upper analog cards, Lower digital (sld) card – Exabyte EXB-8505 8mm User Manual
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Preamp and Upper Analog Cards
A Preamp card (SPR card) contains preamplifier, motor, and write
driver circuitry.
The Upper Analog card (SUA card in the EXB-8505 and EXB-8505XL;
VUA card in the EXB-8205 and EXB-8205XL) contains analog filters,
equalization, and clock-detect circuitry.
Together, the preamp and upper analog cards comprise the write and
read electronics. The write electronics consist of write control circuits
for digital data and servo information, as well as the write head driver
circuits. The read electronics consist of preamplifiers and equalization
circuits for the read channels, the servo channel, amplitude sensing,
and data clocking and detection.
Lower Digital (SLD) Card
The Lower Digital (SLD) card contains the data processor, error
correction code, buffer memory, and control circuitry. The tape
drive’s data buffer includes 1 MByte of dynamic random access
memory (DRAM).
The SLD card controls communication between the tape drive and the
SCSI bus, and can be either of the following:
SLDS (single-ended SCSI)
SLDD (differential SCSI)
The SLD card contains a 8051-compatible microprocessor, which
implements the controller function. The controller function includes
the following activities:
Data compression
SCSI bus management
SCSI command decode and status presentation
Scheduling of all tape drive operations
Motion control management
Data transfer and buffer management
Logical-to-physical block packing and unpacking
Tape formatting; header and search field generation
Read-after-write verification and rewrite management
Tape drive statistics and sense data
Error recovery procedures
Monitor interface
1-megabyte buffer
1-16
EXB-8205 and EXB-8505
510504
(Standard and XL)
1 Features