Apple Logic Board Informações Técnicas descarregar pdf (Página 73)

The following table summarizes the various mode combinations

which are available.

Control

Address Function

$C0N0 4K Bank A; RAM read; Write protect

$C0Nl 4K Bank A; ROM read; Write enabled

$C0N2 4K Bank A; ROM read; Write protect *

$C0N3 4K Bank A; RAM read; Write enabled

$C0N8 4K Bank B; RAM read; Write protect

$C0N9 4K Bank B; ROM read; Write enabled

$C0NA 4K Bank B; ROM read; Write protect *

$C0NB 4K Bank B; RAM read; Write enabled

$C0N4 select 16K Bank 1

$C0N5 select 16K Bank 2

$C0N6 select 16K Bank 3

$C0N7 select 16K Bank 4

$C0NC select 16K Bank 5

$C0ND select 16K Bank 6

$C0NE select 16K Bank 7

$C0NF select 16K Bank 8

Notes:

N = 8 + Saturn 32K board slot # ( for slot 0, N=8).

16K Bank 1 = 1st 16K bank of Saturn RAM board

16K Bank 2 = 2nd 16K bank of Saturn RAM board

4K Bank lA = 1st 4K bank of the selected 16K Bank

4K Bank lB = 2nd 4K bank of the selected 16K Bank

ROM read: The RAM on the Saturn board is disabled for

reading and the main board ROM enabled.

RAM read: The RAM on the Saturn board is enabled for

reading.

Write enable: The RAM on the Saturn RAM board is enabled

for writing.

Write protect: Data cannot be written to the RAM on the

Saturn Board.

* This combination (ROM read and RAM write protect)

effectively disables the Saturn 64K or 128K board.

The board is in this state and Bank 1 is selected

upon power up.

1 2 ... 68 69 70 71 72 73 74 75 76 77

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Apple Logic Board Informações Técnicas Página 73