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Sharp PC-1211

Date of introduction:  June 1980 Display technology:  LCD dot matrix 
New price:  $229.00 (MSRP 1980) Display size:  24 characters
Size:  2.8" x 6.9" x 0.65"
 70 x 175 x 17 mm3
   
Weight:  6.1 ounces, 172 grams Serial No:  97016936
Batteries:  3*MR44 Date of manufacture:  mth 01 year 1981
AC-Adapter:  n.a. Origin of manufacture:  Japan
Precision:  12 Integrated circuits:  CPU: SC43177, SC43178
 RAM: 3*TC5514P
 DISPLAY: 3*SC43125
Memories:  26    
Program steps:  1.4k Bytes Courtesy of:  Ken H. Meine

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:

Micro Compet QT-8D (Oct. 1969): World’s first electronic calculator incorporating LSI ICs
EL-8 (Nov. 1970): World’s first battery operated portable calculator
EL-805 (May 1973): World’s first COS electronic calculator
EL-8020 (1976): World’s first calculator using Film Carrier System and yellow LCD
EL-8026 (1976): First electronic calculator with solar cells (disputed)
EL-8130 (1977): World’s first touch key calculator
EL-8152 (1979): World’s first 1.6mm-thin electronic calculator
PC-1211 (1980): World's first Pocket Computer with BASIC programmability

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:

Product Description MSRP (1980)
CE-121 Cassette Interface $49.00
CE-122 Mini Printer & Cassette Interface,
up to 16 characters per line
$149.00

Dismantling this Sharp PC-1211 manufactured in January 1981 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.

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:

SC43177: CPU 1 - 4-bit microprocessor manufactured by Sharp in a CMOS process and using a 62-pin QFP (Quad Flat Pack) package
SC43178: CPU 2 - 4-bit microprocessor manufactured by Sharp in a CMOS process and using a 62-pin QFP (Quad Flat Pack) package
3*TC5514P: 1k*4 Bits Bytes RAM manufactured by Toshiba in a CMOS process and using an 18-pin DIP (Dual In-line Package) encapsulation
3*SC43125: Display driver with built in RAM (128*4 Bits), manufactured by Sharp in a CMOS process and using a 62-pin QFP (Quad Flat Pack) package

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:

Key input routine
BASIC Interpreter
Execution of manual operation
Power shut-0ff control
Clock stop control

CPU 2

Display processing
Arithmetic routine
Character generator
Cassette routine
Print routine
Buzzer
Power off
Clock stop

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:

PC-1500 (1982): Hand-held Computer with Z80 compatible Sharp LH5801 microprocessor in CMOS technology
PC-1250 (1982): Pocket Computer with Z80 compatible Sharp LH5801 microprocessor in CMOS technology
PC-1401 (1983): First combination of a Scientific calculator with a Pocket Computer with BASIC programmability



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If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, January 23, 2021. No reprints without written permission.