Topping Electronics - A Division Of InspecTech Analygas Group Inc. - 450 Midwest Road, Toronto, Ontario, Canada, M1P 3A9

Telephone: 416-285-1272 Fax: 416-757-8096 EMail: Web:

The Topping Electronics Model 412C PROM module is designed for installation in all type 170 controllers. The 412C can be configured to operate with most software packages, providing the user with an interchange platform for data and programs. A series of soldered jumpers allows for selection of memory map and type of memory devices. Two front panel accessible eight position DIP switches may be used to uniquely identify a controller location, capabilities or any other needed parameter. A crystal controlled Real Time Clock Adjuster (RTCA) circuit may be used to extend the 170 controllers Down Time Accumulator to 72 hours with increased accuracy. A lithium battery is supplied for backup power for volatile memory devices and the RTCA. A battery switch controls backup power for the RTCA circuit only. Power to most components on the 412C is supplied via an on board regulator generating +5V from the 170 controller’s +12V supply.



Total 64K Memory Map
EPROM: 2764, 27128 or 27256
SRAM: 6264 or 62256


Fits standard 170 controller PROM module slot.


Mechanical stop prevents accidental insertion upside down.


Battery and battery holder for one 3.6V AA cell Lithium Thionyl Chloride backup battery.


Five preset memory configurations are provided. Other special configurations can be provided.

Write Protect:

A software controlled write protect circuit is provided to protect RAM during power downs.

Identification Switches:

Two 8 pole identification switch packages are accessible through the front panel.

RTCA Circuit:

A crystal controlled real time clock adjuster circuit is provided. This extends the down time accumulation ability of a 170 controller to 72 hours with increased accuracy.

Battery Switch:

The battery switch controls the standby power for the RTCA circuit only. RAM backup power is always provided when a battery is installed. Note that the battery should be removed from the holder when the module is to be stored for periods in excess of one week.

Download PDF Data Sheet

Model 412C Prom Module