The HP Series 80 was a line of personal computers, accessories, peripherals and software introduced and developed by Hewlett packard during the early 1980's, which marked such company's entry into the personal microcomputer marketplace.
The first computer in this Series was the HP-85, which was introduced in January 1980, and which fit a small CRT, a small thermal printer, and a small tape cartridge drive into a 20 pound package that resembled a small typewriter.
The second computer in the Series was the HP-83 which was introduced in the spring of 1981 ans which was identical to the HP-85 except that it lacked the built in printer and tape drive, obviously in an attempt to lower the price for that portion of the personal computer market that needed a disc drive and full width printer
In the spring of 1982 Hewlett-Packard came out with the third computer in the Series, the HP-87 which was similar to the HP-83 in that it lacked the HP-85's built-in printer and tape drive, but was dissimilar to the HP-83 in that the HP-87 had a full screen built-in unlike the HP-83's tiny built-in screen. The HP-87 also had more memory capability, a built-in HP-IB inferface, and its built-in ROM based operating system had enhacement extending its BASIC language.In the fall of 1982 Hewlett-Packard released the next computer in its Series 80, the HP-86, which was the first in the series not to have a built-in CRT. Purchasers could choose between a 9" or a 12" monitor which attached to the HP-86 by a special cable. The HP-86 also had a built in centronics printer interface, and a pair of built-in specialty disc interfaces which could only connect to HP-9130A disc drives. The HP-86 also had more standard memory than the HP-87.
Virtually simultaneously with its introduction of the HP-86, Hewlett-Packard also introduced an upgraded version of the HP-87, which it called the HP-87XM. The "XM" stood for "extra memory". The HP-87XM had 128K standard user RAM which was more than any previous Series 80 computer. At the time Hewlett-Packard released the HP-87XM the older HP-87 became known as the HP-87A.
The last two computers introduced by Hewlett-Packard to complete its Series 80 line, wer the HP-86B and the HP-85B.
The HP-86B was a revised version of the HP-86. The HP-86B replaced the centronics interface and the two HP-9130A disc drive interfaces, with a built-in HP-IB interface, The HP-86B had as much memory as the HP-87XM but also had built-in e-disc capabilites. At the time the HP-86B was intriduced the HP-86 became known as the HP-86A.
The HP-85B was identical to the the original HP-85, except that it had 32K standard user RAM built-in, and had built-in e-disc and mass stroage ROM capability. At the time the HP-85B was introduced the HP-85 became known as the HP-85A. ROM operating system
These overview descriptions don't disclose and explain every detail and difference between the various Series 80 computers, but, rather, narrates the broad picture. The Series 80 computers had qualities and features which made them stand apart from the crowd of microprocessors of that era. In computer folklore the Series 80 deserves historical recognition.