Apple Logic Board Información técnica descargar pdf (Pagina 24)

C. MORE DETAILS CONCERNING MOVEDOS

When MOVEDOS is executed, the following occurs:

1. A search is made starting at slot 0, and incrementing

upward, for a Saturn 64K or 128K board. if it is not

found, the program halts with an appropriate message.

2. The version of DOS present in RAM is determined (DOS

3.2 or 3.3) and the appropriate modifications are made

to allow it to run (when relocated) up in the RAM

board. The boot routine is modified to allow loading

of DOS from disk directly into the memory card.

INIT is also changed to enable initialization with

the relocated DOS.

3. The modified DOS is then loaded into the Saturn 54K or

128K RAM board.

4. The necessary routines which allow communication with

the relocated DOS are put up at the top of the user

RAM space (occupying 1/2K from $BEOO to $8FFF), and

HIMEM is set to $BEOO.

5. The pointers in page 3 are changed indicating the new

entry points to DOS.

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Apple Logic Board Información técnica Pagina 24