ELITE SERIES USER MANUAL

THEORY OF OPERATION

DOS 3.3 re-enters at $Cn5C using a 6502 JMP. When the PROM is finished, the second stage expects it to transfer control back, via a JMP, to $801.

DOS 3.2.1 does not expect the boot PROM to try to decode the data read on the later calls (the boot sector is a special encoding scheme which differs from the rest of a 13 sector disk).

However, DOS 3.3 does require the boot PROM to decode on these later sectors.

NOTE: The Rana boot code adheres to all the above standard Apple DOS booting protocols, and to several extensions to this protocol in order to support existing software packages.

7.2.3.Hardware

The Elite Controller Card has full data buffer- ing, using a bi-directional bus driver, which pro vides more drive than other controllers yet requires very little drive from the bus. Extensive power switching reduces the power consumption of the data buffer and other circuits.

7.2.4.EPROM Logic

The EPROM is split into two sections ($000—$6FF and $ 700-$7FF). Both sections are mapped into $C800-$CFFF; however only the $000-$6FF section,

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