Alternative Engineering Corp.
P.O. Box 128 - Gardiner, Maine 04345
(207)623-8506


The Viper-ZGRASS System

With over 10 years of custom software development, plus the most advanced 
hardware features ever offered on a home computer, the Viper Z-GRASS system has 
become the most powerful, yet affordable Video Image Processor on the consumer 
market. This unique system together with the Bally/Astrocade Professional 
Arcade has a total of 8 microprocessor devices including 3 original 
Bally/Midway custom graphics processors (used to make such videogame legends as 
Pac Man, Galaxian, Wizard of War, Space Invaders, and many others). Many other 
home computers can play arcade games, but the Z-GRASS computer system is the 
first machine specially designed for writing them. Z-GRASS makes it fun and 
easy to create your own arcade games, video art, graphs, charts, synthesized 
music, plus special sound effects. Almost everyone has ideas for video games 
but only now with Z-GRASS can you put your thoughts in motion without having to 
be a master programmer.


System features:

1. 64K 200ns dynamic RAM memory for programming.
2. 32K custom Z-GRASS real time operating system.
3. Dual RS232 bi-directional, communications ports.
4. 8048 microprocessor controlled keyboard with 1k rom decoder.
5. OAK F.T.M. 81 key computer designed keyboard with keypad.
6. Piezo electric key click for audible keyboard feedback.
7. 8231 high speed arithmetic processor unit.
8. Dual 2000 baud cassette interface ports with motor control.
9. Double Sided/Double Density 5.25 floppy disk controller.
10. RFI/EMI filter with plug-in cord and built-in fuse.
11. Fully regulated DC power supplies 5,12,-12.
12. RS232-microprocessor controlled remote keyboard option.
13. Expandable to high resolution graphics. (320x204-Color)
14. Memory expandable up to 256k with the high res. option.
15. Stereo output jacks for the 3 octave music synthesizer.
16. Compatible with CP/M operating systems.


The Viper Z-GRASS unit plugs into all of the following systems:

The Bally Home Library Computer
The Bally Professional Arcade
The Bally Computer System
Astrocade Professional Arcade Computer
Astrovision Professional Arcade Computer


Z-GRASS The Language.

The Z-GRASS software includes these advanced functions:

1. A full screen text editor for fast efficient program editing.
2. String manipulation including match, concatenation replacement.
3. Program execution in both interpreted and compiled modes.
4. Multi-dimensional arrays and string arrays.
5. User customization of language at several levels.
6. Advanced graphics commands:
   SHRINK, TEXT, ELLIPSE, SNAP, SHOW, ROTATE, SCALE, PATTERN, STRIPE , POINT.
7. 6 user definable keys for special or repetitious functions.
8. Over thirty special control key commands with multiple modes.

This is only a partial list of all the commands that are included in the 32K of 
Z-GRASS software. It takes over 100 pages of the Z-GRASS manual to describe all 
the commands and how to use them. Also included in the Z-GRASS manual are 10 
demonstration lessons in programming with Z-GRASS, plus information on all the 
swap modules that can be bought on disk or cassette tape. These swap modules 
allow the user to get new Z-GRASS commands as they become available.


Dual RS232 Communications Ports.

The RS232-C dual channel communications ports allow your Viper to communicate 
with the outside world. These ports can he used with a wide variety of the 
latest in communications equipment and both channels have independent 
programmable baud rates. (300 to 38.4k baud) The following devices can be used 
with these ports.

1. Printers, dot matrix or letter quality.
2. Bit pad graphics digitizers.
3. Voice synthesizers.
4. Telephone modems.
5. Remote appliance controllers.
6. Computer terminals.
7. Other Z-GRASS computer systems.
8. Remote keyboards.


Microprocessor Controlled Keyboard

The Microprocessor controlled keyboard is a state of the art high speed data 
entry device. This unique keyboard features an 8 character buffer, repeat keys, 
and microprocessor-based multiple key rollover functions with phantom key 
lockout. All keys are debounced to prevent unwanted entries. The keyboard has 4 
level coding, Shift, Unshift, Capslock, and Control. There are 81 keys in the 
standard QWERTY arrangement and the life expectancy per key is a 100 million 
cycles. The switch contacts are front sealed, therefore humidity, dust and 
vibration have no effect on proper operation. The top row of keys have been 
customized for the Z-GRASS computer system yielding us F1 thru F6 for the 
special function keys and four arrow keys for the Z-GRASS editor. Also included 
in the system is a piezo-buzzer that clicks each time a key has been depressed 
to give the user a positive entry response. This buzzer can also be program 
controlled and made to click either in response to or, to gain the attention 
of, the programmer.

Arithmetic processing unit.

The Arithmetic processor is an integral part of the high-speed graphics that Z-
GRASS is capable of producing. This device is standard equipment on the Viper 
but is normally offered as an option costing several hundred dollars on other 
computers systems. The APU increases the speed of the mathematical computations 
up to several hundred times and is therefore essential in producing the real 
time responses needed for complex graphics simulations.

Functions:

1. Fixed point single and double precision. (16/32 bit)
2. Floating point single precision. (32 BIT)
3. Full binary data formats.
4. Addition, subtraction, multiplication and division.
5. Trigonometric and inverse trigonometric functions.
6. Square roots, logarithms, exponentiation.
7. Float to fixed and fixed to float conversions.
8. Stack oriented operand storage.

Fortunately all of the above mathematical formulas are executed transparently 
to the user and are completely controlled by the Z-GRASS software. This device 
has been manufactured using the most advanced N-Channel Silicon Gate Technology 
and therefore is extremely fast and reliable.

2000-Baud Dual Cassette Interface with Motor Controls.

The Dual 2000-Baud Cassette Interface is used to store and retrieve programs 
from a cassette recorder. The system includes 2 separate cassette ports with 
individual motor controls. Having 2 separate systems allows more complex 
functions to be easily executed. With the computer controlling the motors, one 
cassette could be the audio instructions, while the other is loading program 
material into the computer. The dual motor controls can also be used to let the 
computer start and stop the cassettes to merge files or select audio or program 
data.

5.25 4 Channel Floppy Disk Controller.

The WD1770/ 5.25 Floppy Disk Controller/Formatter from Western Digital is the 
latest in floppy disk technology. This controller contains a digital data 
separator and write precompensation circuitry to insure optimum data integrity 
to and from, the disk. This 5.25 floppy disk controller is capable of driving 
up to 4 single or double sided/double density disk drives. The total amount of 
memory capable of being accessed using double sided, double density mode with 
the IBM MFM format would be approximately 1.5 million bytes.

The Z-GRASS software is programmed for double density formatting in order to 
get the most memory storage per disk. Although this floppy disk controller is a 
custom version for 5.25 disk drives it maintains complete compatibility with 
its predecessors and therefore can be connected to all standard 5.25 disk 
drives.


Power Supply Features.

The system power sections include 1 switched 120v 3 prong grounded outlet on 
the back panel to be used for the Bally/Astrocade wall transformer. This outlet 
will turn your Bally/Astrocade unit on and off with the Viper Zgrass unit. The 
front panel on/off switch is illuminated for your convenience and is a good 
quick reference to insure whether the system is on or off.
In an effort to diminish the effects of low voltage and power spikes causing 
computers to intermittently fail, the Viper has a specially designed 
microprocessor power transformer that is capable of operating at 100% 
efficiency even when the power lines drop well below 110 volts. To help protect 
the system from radiated noise, the Viper also includes a high efficiency 
RFI/EMI AC line filter with fuse compartment, and the addition of a M.O.V. 
(metal oxide varistor) for Hi-Voltage spike protection.

Audio Mixing and Stereo Outputs.

With the Viper Z-GRASS system you can use either your TV or your stereo sound 
system to listen to the sound effects of the music synthesizer. You can also 
play your cassette recorder thru the TV or stereo system thanks to a special 
circuit in the Viper. With this unique flexibility you have complete voice and 
music capability for Computer Aided Instruction, Adventure games, and many 
other applications where high quality sound and programs can interact.