The PC-5000 was largely IBM PC-compatible, with the same 4.77-MHzIntel8088processor as the IBM PC, and ran MS-DOS 2.0 (in ROM). It had 128 kilobytes of internal memory (it was one of the few computers to use bubble memory), which could be expanded by the use of plug-in cartridges. The cartridge slots also accepted ROM cartridges containing software, such as the Extended BASICprogramming language and the EasyPac software suite, which contained the EasyWrite II word processor, EasyReport reports program, and EasyComm terminal software for use with the internal modem. It featured a 640×80-pixel (80-character by 8-line) LCD display, a full-transit keyboard, and an external dual 5.25-inch floppy disk drive. A notable feature of the computer was its built-in thermal printer, which could also be purchased separately and attached to the machine. It is perhaps due to this attachment that the case design of the PC-5000 owes much to that of electronic typewriters of its time.