Siemens PC-D

Siemens PC-D

Type	Personal computer
Release date	PC-X: 1982 (1982) PC-D: 1984 (1984)
Discontinued	1986
Media	5¼″ floppy disk, hard disk
Operating system	PC-X: SINIX, PC-D: MS-DOS 2.11
CPU	Intel 80186 @ 8 MHz
Memory	128 KB – 1 MB
Successor	PCD-2

The PC-D and PC-X were personal computers sold by Siemens between 1982 (PC-X)/1984 (PC-D) and 1986. The PC-D was the first MS-DOS-based PC sold by Siemens, though it was not fully compatible with the IBM PC architecture. It was succeeded by the PCD-2.

Hardware

Most of the hardware was identical. While the PC-X was equipped with 1 MB of RAM, a hard disk and a MMU, the PC-D came with 128 kB of RAM and a single 5¼″ floppy disk drive in its basic configuration. More powerful configurations with 256 kB, 512 kB or 1 MB and either a second floppy disk drive or a hard disk with a capacity of 13 or 20 MB were also available. The keyboard layout differed between the two models.

The PC-D had a certain level of compatibility with the IBM PC architecture but differed in a number of aspects:

• Intel 80186 processor
• Double-density floppy disk drives with a proprietary 80-track format (729,088 bytes)
• Proprietary monochrome graphics adapter with a resolution of 640×350 pixels and black-on-white text mode (which could be inverted through a software tool)
• 12″ monochrome monitor, powered through the graphics card
• V.11 serial ports for keyboard and mouse (the latter being optional)
• Different keyboard layout: among others, the PC-D had a Help key and keys to control a connected printer but only five cursor keys (←↓↑→ and Home)
• Both V.11 and V.24 ports for printers
• A parallel port was available only as an add-on; if not installed, LPT1: and LPT2: would address the serial ports
• Proprietary VG96 Local Bus
• The power switch could be inhibited in software
• A debug button (located next to the reset button) to display the contents of the processor registers
• The mainboard had a SCSI interface, although hard disks had a ST506 interface and were connected to a separate controller board.

Optional hardware included:

• a two-button mouse
• the PT20 daisy wheel printer, the PT88 (available as ink jet or pin printer) or the PT89 (the A3 variant of the PT88)
• the UTC 101, UTC 421-1 or UTC 424-4 teletex controllers, the latter of which could also be used to network up to four PC-Ds
• a tape drive with a capacity of 45 MB

Software

The PC-D shipped with MS-DOS 2.11 (version 3.20 became available later), which was extended with a menu system through which users could launch applications without having to use the command line. Application software included:

• Microsoft Word
• Microsoft Multiplan
• Microsoft Chart
• dBase,
• GW-BASIC interpreter and compiler
• Lotus Spotlight, an application suite which consisted of a notepad, calculator, calendar, card file, phone book and file manager which could be launched on top of other running DOS applications
• Open Access, an office suite which included a database, a spreadsheet application, a charting tool, a calendar and a BBS terminal
• A 9750 terminal emulation for BS-2000 mainframe access
• Some simple games
• Microsoft Windows 1.0

Hardware calls on the PC-D differed from those on fully IBM compatible PCs, causing most DOS applications to crash on the PC-D unless they were recompiled or patched, making them incompatible with IBM PCs. Windows applications could usually be exchanged between both platforms.

The PC-X shipped with SINIX.