EMAC PRIMER Instruction Manual page 6

Unit Description
The standard PRIMER will allow the student to enter programs into the units' memory, allow the student to run them, and
to view the results.
The Monitor Operating System ( the standard monitor software in EPROM ) included will cause the keyboard controller chip
to scan the keypad buttons, interpret the entries, and allow storage of data into the 256 byte RAM included in the PRIMER.
The operating system also displays related data on the 6-digit LED display. The operating system will allow the student to
examine the data stored at various memory locations, examine the contents of the microprocessor's registers and other
functions, via the display and keypad. The operating system software will permit the student to run ( execute ) the program
entered, and to execute the program in steps, instruction by instruction, to permit debugging of programs.
The instruction manual contains several lessons in which the student may write programs to access and use the digital I/O,
analog I/O, and experiment with the sound port, interrupts, and timers. All that is needed to perform this is included in the
basic PRIMER kit.
Optional Hardware and Software
POWER SUPPLY
Any filtered DC power source from seven ( 7 ) to ten ( 10 ) volts DC may be used to power the PRIMER. Power is
fed to the unit via power jack J1. Make sure that the power supply's output plug has a positive tip and a negative
sleeve. Current consumption will be less than 500 mA. ( 350mA to 420mA typically ). If desired, a wall plug/DC
power supply with built in power plugs may be ordered separately. Note: Be careful to observe correct type of
voltage and polarity, or else the PRIMER may be seriously damaged!
MEMORY
The PRIMER's built-in RAM memory is 256 bytes. The Monitor Operating System uses a few bytes at the top of
this memory. This leaves more than two-hundred bytes for code that may be entered, which is quite a lot
considering it is entered by hand. However, if larger memory is desired, as is the case when higher level operating
systems such as E-FORTH and MT-BASIC are used, an additional 32 K byte static RAM may be added. Also an
Extended Monitor Operating System (EMOS) may be installed in place of the standard Monitor Operating System
EPROM.
DATA/FUNCTION KEYS
The standard PRIMER comes with a twenty key keypad to select functions, and enter data.
COMMUNICATION PORT
Without all the options, the PRIMER is a powerful, stand-alone unit that has the potential to do more than just be a
training device. It has a easy to use interface that has the potential, with a little more hardware added to become a
full blown computer/controller. One of the additions to the PRIMER that help accomplish this end is the Serial RS-
232 Communication Port. With this hardware option installed, the PRIMER can communicate with a terminal or
PC, permitting greatly increased flexibility. This option is essential when the high-level language EPROMS are
installed on the PRIMER.
EXPANSION PORT
The expansion port is a 50 pin header connector that provides access to the 8085 microprocessor's multiplexed
Address/Data Bus, control signals, and PRIMER DC power. Connection of other circuit cards to this bus allows
the PRIMER to perform an almost unlimited number of functions. The connector footprint allows the PRIMER to
interface with most of EMAC's standard peripherals, the most notable being EMAC's EPROM Programmer card
and digital parallel I/O board. The connector also has extra pins not used by EMAC peripherals, but which are
useful to the students who may design peripheral boards of their own.
EXTERNAL I/O PORT
The External digital I/O port connector can be added at any time to provide direct access to the TTL level digital
output and input lines, via a ribbon cable. These ports are 8 bits each, and are in parallel with the DIP switch and
output LEDs. The I/O port connector permits easy access to the I/O lines so the student may connect switches
and relay contacts to the digital input lines and relay drivers, solid state relays (SSRs) to the output lines. These
inputs and outputs are used to allow the PRIMER to control various devices for very interesting projects.
6