Apple Logic Board Technical Information PDF herunterladen (Seite 7)

Chapter 1

INTRODUCTION

The Saturn 64K and 128K Ram Boards are expansion plug—in

cards designed to provide an extra 64K or 128K bytes of random

access memory for Apple II and Apple II plus computers. To make

use of the additional memory, Saturn Systems provides a package of

applications software at no additional charge. The Saturn RAM

boards and accompanying software require that the Apple be

outfitted with a full 48K of main board RAM, as most Apples are

today.

The 64K and 128K Ram boards are compatible with software

designed to run with Apple’s Language Card (PASCAL, FORTRAN, LISA

ver 2, etc.) as well as Microsoft’s RamCard and Z80 Softcard

(CP/M, COBOL—80, FORTRAN—80, etc.). This compatibility is

possible due to its unique organization. The boards consist of

16K banks of memory (4 banks for the 64K board, 8 banks for the

128K), accessed one at a time. In this sense, the Saturn 64K or

128K board can be thought of as several 16K Ram boards occupying

the same slot. The first of these 16K banks is controlled

through software in exactly the same manner as Apple’s Language

Card and other 16K memory cards. As a result, existing software

designed to run with the 16K memory boards and Apple Language

Card will operate on the Saturn 64K or 128K board without modifi-

cation.

Using DOS 3.3, the version of BASIC not resident in ROM

(Integer for an Apple II plus or Applesoft for an Apple II) will

automatically be loaded into the first 1.6K of the Saturn RAM

board upon boot. This enables easy access to either BASIC (via

INT or FP). In this respect the Saturn 64K or 128K board appears

as a 16K RAM board. However, in addition to this first bank of

16K, higher banks are available as well. The software provided

with the 64K and 128K boards takes advantage of the additional

memory, allowing you to:

1. Relocate DOS to free up user memory.

2. Emulate a disk drive under DOS, PASCAL, or CP/M.

3. Store arrays and subroutines from Applesoft or Integer

Basic.

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Apple Logic Board Technical Information Seite 7