The HP-83 was second model introduced in the Series 80 line of personal computers, coming out in the spring of 1981, several months after the introduction of the HP-85A.
The HP-83 was completely compatible with the HP-85A; interfaces, ROMs, and all else were interchangeable between these two products. In fact, they were indentical except that the HP-83 did not come with the tape cartridge drive and the thermal printer that were integrated into the HP-85A.
The HP-83 was designed for business and technical professionals who required disc storage and a high-speed, full-width printer, but who had no need for the tape drive and thermal printer that were built into the HP-85. The HP-83 consequently was priced significantly less than the HP-85. The two functional additions to the HP-83 were autostart from disc and peripheral paper advance control from the keyboard.