HP-85A - Introduction The desktop calculator / computer HP-85A was introduced in January 1980. It contains by HP customized CPU keyboard 16 kB dynamic RAM (expandable to 32 kB with external 16 kB module) 5" black-white CRT (16 lines of 32 characters, or 256×192 pixels) tape drive for DC-100 cartridges (210 kB capacity, 650 B/s transfer) thermal printer . The CRT and printer display graphics in addition to text.The printer has print screen function, it can copy anything shown on the screen. On the rear of the HP-85A are four slots for expansion modules for RAM or ROM extensions, or interfaces such as RS-232 and GPIB.