The Apple Computer is a complete microprocessor system, consisting of a Mos Technology 6502 microprocessor and support hardware, integral video display electronics, dynamic memory and refresh hardware, and fully regulated power supplies. It contains resident system monitor software, enabling the user, via the keyboard and display, to write, examine, debug, and run programs efficiently; thus being an educational tool for the learning of microprocessor programming, and an aid in the development of software.

The integral video display section and the keyboard interface renders unnecessary the need for an external teletype. The display section contains its own memory, leaving all of RAM for user programs, and the output format is 40 characters/ line, 24 lines/page, with auto scrolling. Almost any ASCII encoded keyboard will interface directly with the Apple system.

The board has sockets for up to 8K bytes of the 16 pin, 4K type, RAM, and the system is fully expandable to 65K via the edge connector. The system uses dynamic memory (4K bytes supplied),

although static memory may also be used. All refreshing of dynamic memory. including all "off- board" expansion memory, is done automatically. The entire system timing, including the microprocessor clock and all video signals. originates in a single crystal oscillator.

Further, the printed circuit board contains a breadboard area", in which the user can add additional "on-board " hardware (for example, extra PIA's, ACIA's, EROM's, and so on).

This manual is divided into three Sections:

Section II USING THE SYSTEM MONITOR. (listing included)

Please read Section l thoroughly, before attempting to "power-up" your system, and study Section III carefully before attempting to expand your system. In addition to this manual, Apple "Tech Notes" are available which contain examples of expansion hardware and techniques.

The Apple Computer is fully assembled, tested, and burned in. The only external devices necessary for operation of the system are: An ASCII encoded keyboard, a video display monitor, and AC power sources of 8 to 10 Volts (RMS) @3 amps and 28 Volts (RMS) @l amp. The following three articles describe the attachment of these devices in detail.

Any ASCII encoded keyboard, with positive DATA outputs, interfaces directly with the Apple system via a "DIP" connector. If your keyboard has negative logic DATA outputs (rare), you can install inverters (7404) in the breadboard area. The strobe can be either positive or negative, of long or short duration. The "DIP" keyboard connector (B4) has inputs for seven DATA lines, one

STROBE line, and two normally-open pushbutton switches, used for RESET (enter monitor), and CLEAR SCREEN (see schematic diagram, sheet 3 of 3, for exact circuitry). This keyboard connector also surplice three voltages, (+5V, +12V, and -12V) of which one or rnore may be necessary to operate the keyboard. Pin 15 of the keyboard connector (B4) must be tied to +5V (pin 16) for normal operation.

NOTE: The system monitor accepts only uppercase alpha (A-F, R).
It is therefore convenient, though it's not essential, to have a keyboard equipped with uppercase alphalock (usually in the electronics). Either of the following suggested circuits may be used to provide alpha lock capability, if needed, and can be built in the breadboard area.

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