RANA Systems Elite Controller, User Manual

Page: 170 / 328

ELITE SERIES USER MANUAL THEORY OF OPERATION
7 . 2 . E l i t e C o n t r o l l e r
7 . 2 . 1 . I n t r o d u c t i o n
The four disk drives allowed with each Elite
Controller card are grouped into two pairs with
drives 1 and 2 (Bank 0) selected when power is
first applied.
They may be addressed using the standard “Dl”
and D2” used by most Apple software. With a
special command to the controller to select Bank
1, drives 3 and 4 will respond as if they were
drives 1 and 2. An LED indicates when the
second bank (drives 3 and 4) is selected.
An EPROM, containing the Rana boot code, is
located on the controller card. The Rana boot
accommodates both the standard Apple 13 and 16
sector formats. The controller card is also
compatible with the special “copy protected” 16-
sect or boot formats since, in a general sense,
only the initial boot sector must be read by the
boot PROM. Following this, the user software
(or DOS) handles any special formats.
The EPROM is switched into and out of the per-
ipheral expansion space ($C800-CFFF) using the
protocol recommended by Apple. An LED, located
on the Controller Card, indicates when the Rana
boot EPROM is switched into the expansion space.
P a g e 7 — 7