The Harris D1200/H400 is an SPC Digital PABX, with a maximum capacity of approximately 800
extensions. It is available in seven variations: D1201, D1202, D1203, D1204, D1205, H400-2
and H400-4. The variations describe the size of the cabinets and whether there is a
redundant common control. The D1201 is the most common model.
Both the D1200 and H400 use the same type of printed circuit boards and Operating Systems.
Only the backplane and databus signalling layout is different.
All systems can support the Customer Features Processor (CFP) except the D1203. The CFP in
used to supply additional features such as Automatic Route Selection (ARS).
All systems are approved for use by telephones with decadic or MF4 signalling and the use
of time break recall.
Made by Harris Systems Ltd(USA)
Distributed and installed by Digital Telephone Systems Ltd
The Software for the Harris range of systems has a 3 section structure. Each having a well
defined function within the system.
1. OPERATING SYSTEM - this is PROM based and supplies the basic telephony function of the
switch. Thus, even if the Moves and Changes (MAC) processor and/or the CFP fail the system
will still work as a basic PABX.
2. CUSTOMER CONFIGURATION - this runs the MAC processor. It is EEPROM based, configurable
and is loaded from an IBM compatible P.C. The IBM compatible P.C. is owned by the
customer. It must have at least 256K of RAM and the software can be supplied on S* or 31
inch floppy disc.
3. CUSTOMER FEATURE PACKAGE - this runs the Customer Features Processor (CFP). It is RAM
based and can be loaded via tape or disc. If FP3 or FP5 it is installed and edited via the
TTY. If FP6 or FP7 it is edited via an IBM compatible P.C.