Sharp PC-1210

Sharp Corporation introduced in June 1980 with the PC-1211 (and its sibling PC-1210) the World's first Pocket Computer with BASIC programmability. While it looks at first glance like a continuation of the EL-5100, a keystroke Programmable Pocket Calculator introduced in June 1979, did the PC-1211 add another medal to the impressive list Sharp's Calculator Innovations:

We assume that both Hewlett Packard and Texas Instruments, leading in 1980 the market or Programmable Pocket Calculators were impressed by the Sharp PC-1211 and its identical twin Tandy Pocket Computer PC-1, the former company introduced roughly one year earlier with their HP-41C the successor of the ancient HP-67 and the latter was working on "Project X" with the goal to replace its legendary TI-59 and regain leadership in the cat and mouse game with Hewlett Packard.

Learn more about the demanding "Project X" initiated already in Summer 1977 and leading not only to the (failed) TI Programmable 88, but the TI-66 PROGRAMMABLE, failed TI-76 PROGRAMMABLE, Compact Computer CC 40, (failed Compact Computer CC 70) and last but not least the successful TI-74 BASICALC and TI-95 PROCALC.

With both Matsushita and Casio joining Sharp within 12 months with their Panasonic HHC series and FX-702P respectively, the market of keystroke Programmable Pocket Calculators plateaued in 1981 at 600k units and started to decline in 1982 to about 500k units. Hewlett Packard joined the market of Pocket/Hand-held Computers in September 1982 with the HP-75C and Texas Instruments followed in January 1983 with the Compact Computer 40, marketed as Advanced Language Computers.

Both PC-1210 and PC-1211 feature on the left side of the compact housing a small peripheral connector and Sharp introduced two fitting peripherals for the Pocket Computers:

Dismantling this Sharp PC-1210 manufactured in June 1980 by Sharp Corporation in Japan reveals a complex design based on two printed circuit boards (PCBs) stacked on top of each other. The larger of the two PCBs looks very familiar to us, it has a striking similarity with the PCB of the EL-5100 and is populated with a 4-bit microcontroller and three Integrated Circuits (ICs) to drive the alphanumeric LC-Display with 144*7 pixels. The real deal of the PC-1211 is the smaller of the two PCBs with a second 4-bit microcontroller and three RAM (Random-access Memory) chips. The PC-1210 is identical to the PC-1211 but sports only one of the RAM chips. Learn how to decipher the 09054506 Date code hidden in the serial number of the pictured calculator.

The two PCBs of the PC-1211 Pocket Computer hold an impressive list of ICs and Sharp proved again the leadership of Japanese companies in miniaturization:

The two 4-bit microcontrollers CPU 1 and CPU 2 share a common data bus with the three RAM chips and the three Display chips and share their tasks well balanced.

CPU 1:

CPU 2: 

Texas Instruments chose with the TI Programmable 88 in 1979 a different approach of balancing the tasks between the two 4-bit microcontrollers with CD2901 combining keyboard and display control and arithmetic functions and having CD2902 accessing the RAM and external ROM memory.

Sharp created in June 1980 with the introduction of their PC-1210 and PC-1211 an new market that we would reference today as "Affordable Pocket/Hand-held Computer". The cat and mouse game between Hewlett Packard and Texas Instruments during the second half of the Seventies for the leadership of Programmable Pocket Calculators was in the first half of the Eighties playing between Sharp and Casio for the leadership of Portable Computers.

Sharp Corporation continued the development of Pocket/Hand-held Computers and introduced within a few years: