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.[1][3] 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.[1][4] 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[1]
- Double-density floppy disk drives with a proprietary 80-track format (729,088 bytes)[1]
- 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)[1][3]
- 12″ monochrome monitor, powered through the graphics card
- V.11 serial ports for keyboard and mouse (the latter being optional)[1]
- 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)[1]
- Both V.11 and V.24 ports for printers[1]
- 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) issued an NMI, by default dropping into a monitor ROM 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[5]
- the PT20 daisy wheel printer, the PT88 (Siemens' ink jet printer) or the PT89 (the A3 variant of the PT88)[4][5]
- 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[4][5]
- a tape drive with a capacity of 45 MB[4]
