The Philips P2000

Technical description

The P2000 Microcomputer is available in two versions:

The P2000 T-version consists of one cabinet, the basic cabinet. This computer interfaces to either a standard black/white or colour television set or a special set with non-modulated R.G.B. interface. The basic cabinet includes a keyboard and minicassette drive and is equipped with a serial printer interface. Standard programs are available on ROM-cartridges which can be plugged into a slot on the cabinet. A second slot is available for installation of an optional interface adaptor, for example a modem-interface.

The P2000 M-version consists of two cabinets, the basic cabinet and the monitor cabinet. The basic cabinet includes the same functions as the T-version, but interfaces to a professional monitor in the monitor cabinet. This monitor cabinet is also the housing for up to 2 mini floppy disk drives.

System description

The P2000 is a microcomputer system consisting of four functional groups:

The main difference between the T- and M-version of the P2000 is found in the video generation. The T-version interfaces to a standard black/white or colour television set and is controlled by logic circuitry on the CPU-board. It uses the 40 character per line colour teletext/viewdata character set. The M-version interfaces to a professional 12" monitor and is controlled by logic circuitry on a separate video board. This board generates 80 characters per line monochrome. For both versions the extension board is optional.

CPU

The CPU is a Zilog Z80 microprocessor running at 2.5 MHz. The u-processor offers a 16 bit addressbus and an 8 bit databus. Instructions are fetched via the databus. The instruction set includes a wide variety of instructions such as logical and arithmetic operations, jump and move instructions, a set of memory load and store commands and I/O instructions. During memory operations the address bus carries the specific memory address. During I/O operations the address bus carries the specific portnumber which is involved. The selection of the particular memory area and the selection of a particular I/O port is done by decoding a part of the addressbus.

MEMORIES

The CPU is addressing a number of memory areas, each of them with a specific function.