Mitsubishi Electric Apricot LS Pro, Hardware Technical Reference

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Peripheral items
Chapter 4
Chapter 4
Chapter 6
Appendix A
Appendix C
Pr
eface
Chapter 4
4/14 LS PRO HARDWARE TECHNICAL REFERENCE
The three jumpers are labelled DS (Drive select), CS (Cable select) and SP (Slave
present). In the LS Pro application the DS jumper must be fitted and the CS and SS
jumpers not.
Warning
None of the other jumpers are used in this application. If any of the other jumpers are installed
the drive will not function correctly.
Drive format The physical format of the drive is as follows:
Disks 3
Heads 6
Tracks 14,688
Formatting
The drive is low level formatted during manufacture. This format has been optimized
to allow the drive to provide maximum performance. Standard low level formatting
programs can only reduce the performance of the drive.
Warning
Do not attempt to perform a low level format on a ProDrive, this can only adversely affect
the performance of your drive. If you do try to format your drive most standard low level
formatting programs will return a “Drive formatted” message very quickly. In fact, the drive
has not been formatted.
Discache The ProDrive LPS 525AT drive is fitted with 512kbytes of RAM and look-ahead cache
circuitry known as Discache.
When a read access is made to the drive, Discache loads subsequent data into the RAM.
If an attempt is made to read this data it is accessed from RAM rather than from the
disk, thus considerably reducing access times.
Cache performance benefits tend to be application dependent. Discache has a number
of alterable parameters which allow the cache to be configured for maximum
performance benefit in any given application.
Full information on configuring Discache is given in the Quantum specification.