Apple Logic Board Información técnica descargar pdf (Pagina 35)

F. RESERVING SPACE FOR BASIC

Space in a Saturn 32K, 64K or 128K RAM Board can be reserved

for the alternate BASIC (Integer BASIC in Apple TI Plus; by not

attaching the first 12K block (block designation #8) of the

Saturn RAM board. The 4K block (designation #32) may be used for

storage by RAMEXPAND without disturbing BASIC in the 12K block.

G. USING A FIRMWARE CARD

If An Apple Firmware card is present in the system, the

RAMEXPAND system can be accessed from it as well. This is accom-

plished by first configuring the relocated DOS to access the

language in the firmware card (see Chapter 4). Operation in this

manner will enable one to gain maximum benefit of the extended

RAM from both Applesoft and Integer BASIC.

III. PRECAUTIONS

A. PROTECTING RAMEXPAND

Since RAMEXPAND occupies the block with designation number

64, this block should not be specified for use by RAMEXPAND. If

the relocated DOS is being used, the block containing it should

also not be specified (#16).

B. SETTING MAXFILES

Once the low RAM portion of RAMEXPAND (RAMEXPAND.LOW) has

been installed, it cannot be moved. As a result, MAXFILES must

not be increased after RAMEXPAND has been installed. What should

be done is to declare the largest value of MAXFILES required

prior to running RAMEXPA.LOAD.

C. RELOADING RAMEXPAND

Everytime RAMEXPA.LOAD is run, the low RAM portion of

RAMEXPAND is loaded and MAXFILES is lowered to protect it. By

simply re—running this program, HIMEM will continue to be

lowered. To prevent this from happening, execute a MAXFILES

command to reset HIMEM before re—loading RAMEXPAND.

D. SWITCHING BETWEEN BASICS (FP OR INT)

Whenever FP or INT is executed (used when switching BASICS,

etc), HIMEM must be declared so as to protect the low RAM portion

of RAMEXPAND. If this is not done, then the data saved by

RAMEXPAND will be lost. The required value for HIMEM is given

when RAMEXPA.LOAD is run.

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Apple Logic Board Información técnica Pagina 35