![P8000](https://upload.wikimedia.org/wikipedia/commons/f/f0/P8000.jpg)
The P8000 is a microcomputer system developed in 1987 by the
VEB Elektro-Apparate-Werke Berlin-Treptow „Friedrich Ebert“ (EAW) in the German Democratic Republic (DDR,
East Germany
East Germany, officially the German Democratic Republic (GDR; german: Deutsche Demokratische Republik, , DDR, ), was a country that existed from its creation on 7 October 1949 until its dissolution on 3 October 1990. In these years the state ...
). It consisted of an
8-bit
In computer architecture, 8-bit Integer (computer science), integers or other Data (computing), data units are those that are 8 bits wide (1 octet (computing), octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) arc ...
and a
16-bit
16-bit microcomputers are microcomputers that use 16-bit microprocessors.
A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
and a Winchester disk controller. It was intended as a universal programming and development system for multi-user/multi-task applications. The initial list price of the P8000 was 172,125
East German mark
The East German mark (german: Mark der DDR ), commonly called the eastern mark (german: Ostmark, links=no ) in West Germany and after reunification), in East Germany only ''Mark'', was the currency of the German Democratic Republic (East Germa ...
s
(around 860,000–1.7 million DM).
There was also a budget version with only an 8-bit microprocessor.
The 8-bit microcomputer
The 8-bit version of P8000 was completely contained on a single 4-layer printed circuit board. The processor, with a clock frequency of 4 MHz, was based on the
U880 microprocessor (near clone of
Zilog Z80) and peripheral circuits along with the U8272
floppy-disk controller
A floppy-disk controller (FDC) has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC directs and controls reading from and writing to ...
.
Direct memory access was accomplished by
U858 DMA controller chip..
The system featured a main memory of 64 KB dynamic RAM, an 8 K
EPROM, and a 2 KB static RAM for boot code, system test routines and the system monitor. This extra memory could be moved or turned off in 4-KB-stages in the 64 K address space.
The 8-bit machine had four serial ports, designated tty0 to tty3. These interfaces could operate either as
V.24
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such ...
or IFSS (''Interface sternförmig seriell''–20 mA
current loop) signals. In addition the computer had a
parallel port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel ...
which allowed the connection of an EPROM burner. Another internal 32-bit parallel interface was used for the coupling the 8-bit to a 16-bit microcomputer card. Data exchange was via two built-in 5.25" floppy drives. Two additional 5.25" or 8" floppy drives could be connected externally.
The 16-bit microcomputer
The 16-bit version of P8000 was divided into two functional units: the 16-bit processor card and up to four plug-in memory cards with sizes of 256 KB or 1 MB. The 16-bit processor was contained on a 6-layer PC board. The processor operated at a clock frequency of 4 MHz and was based on the
U8001 (
Zilog Z8001
The Z8000 ("''zee-'' or ''zed-eight-thousand''") is a 16-bit microprocessor introduced by Zilog in early 1979. The architecture was designed by Bernard Peuto while the logic and physical implementation was done by Masatoshi Shima, assisted by a ...
clone) 16-bit microprocessor . Three U8010
memory management units (MMUs) augmented with special control logic handled the dynamic memory segment allocation and protected against unauthorized access. In addition the computer had 16 KB EPROM memory and 2 KB static RAM For the system Monitor and self-test routines. The peripheral circuitry was built around the U880 family. Dedicated control logic ensured the coordination with the U8001.
The 16-bit machine had four serial ports, designated tty4 to tty7. The interfaces handled both V.24 and IFSS signals. The 8-bit processor was connected to the 16-bit processor via an internal 32-bit parallel interface. Connection to the external Winchester disk was accomplished by another parallel port.
Winchester disk controller
The Winchester-Disk controller (WDC) is an intelligent disk controller and was located in a separate unit, the Winchester disk enclosure. This unit contains the Winchester disk controller and up to two hard drives.
The WDC was based on the U880 microprocessor. An 8 KB EPROM stored the firmware. A 6 KB static RAM served as a buffer between the host computer to the disk . The WDC communicated with the host over an eight-bit-wide parallel interface in conjunction with additional control logic. The interface handled transmission of data blocks plus the command and acknowledgment information.
The system could support up to two identical drives using an
ST-506 interface. The initial drive parameters were stored in the firmware, however with firmware version 4.2 it was possible, to use any
MFM disk. From version 4.2 up the first sector of the disk stored the disk parameters in addition to bad sector information,
The terminal
The P8000 terminal served as the input and output device of the P8000. It consisted of a green screen, a keyboard and a controller. The terminal could operate as an ADM-31 or VT100. It could switch between two character sets, which were stored in separate EPROMs. The interface operated in either V.24 or IFSS mode. The controller was based on a U884 and the graphics controller on o KR580WG75 (Intel 8275) chip. It used a
piezoelectric speaker
A piezoelectric speaker (also known as a piezo bender due to its mode of operation, and sometimes colloquially called a "piezo", buzzer, crystal loudspeaker or beep speaker) is a loudspeaker that uses the piezoelectric effect for generating sou ...
to issue audible alerts.
P8000 Compact
Developed in 1989, the P8000 Compact was an enhanced version of the P8000. In this system the Winchester disk controller and hard drive were contained within in the housing of the host computer, eliminating the extra cabinet. In contrast to the P8000, the P8000 Compact was a 16-bit system with a battery-backed
real-time clock standard. Optionally the P8000 Compact was also available with a third CPU, the
U80601
The U80601 was a 16-bit microprocessor made in 1989-1990 by Kombinat Mikroelektronik Erfurt in the former German Democratic Republic of East Germany. It was manufactured in NMOS technology and encased in a PLCC or ceramic (CLCC) package (first ...
(
Intel 80286 clone). The P8000 Compact was the last computer developed by EAW.
Operating Systems
The following operating systems were available for the P8000:
* UDOS – compatible with
Z80-RIO
The Z80 Operating System with Relocatable Modules and I/O Management (Z80-RIO) is a general-purpose operating system developed by Zilog in the late 1970s for various computer systems including the ''Z80 Micro Computer System'' (MCZ-1) series and th ...
* OS/M – compatible with
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/ 85-based microcomputers by Gary Kildall of Digital Research, Inc. Initial ...
* IS/M – compatible with
ISIS-II
ISIS, short for Intel System Implementation Supervisor, is an operating system for early Intel microprocessors like the 8080. It was originally developed by Ken Burgett and Jim Stein under the management of Steve Hanna and Terry Opdendyk for the ...
* WEGA – compatible with
UNIX
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...
* IRTS 8000 – a real-time operating system
* DCP (only with the third CPU under WEGA ) – compatible with
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...
References
External links
* {{cite book, last1=Elektro-Apparate-Werke, title=P8000 Compact, url=http://www.pofo.de/P8000/notes/P8000_compact.pdf, accessdate=Sep 12, 2016, language=German
Science and technology in East Germany
Microcomputers
Goods manufactured in East Germany