Sharp PC-1270 Pocket Computer Specifications


Developing Programs



The Sharp PC-1270 is a run-time-only pocket computer that executes programs written in SBC BASIC. It can execute complex, lengthy programs and yet provides an extremely easy-to-use and un-intimidating interface for the user.  It is a "dedicated purpose" tool that is quite powerful yet very cost-effective.

The programs installed in the PC1270 cannot be changed, deleted, or even read by the user.  With the PROM CF-Series Flash cards, the program is stored permanently and will not be lost even if the calculator's batteries are completely dead.

The calculator uses a very accurate arithmetic calculation method that is ideal for financial and insurance institutions.  Complex financial calculations can be performed with 10-digit floating-point BCD precision.

Developing Programs

Programs were developed for the PC-1270 by two methods.

For simpler programs, the program were developed on one of the other Sharp Pocket Computers that has a full qwerty keyboard (PC-1250A, etc.).  These calculators allowed you to enter, edit and run a program.

When the project is complete, the program was transferred to the PC-1270 using either a cassette player interface (included with the CE-123P Printer System) or an EA-129C interconnecting cable.  The program was stored on a RAM card in the PC-1270.

PROM's SBC Development System allowed the development of programs on a PC, using conventional text or programmer's editors.  Programs written using the enhanced SBC language does not require line numbers and allowed the use of long variable names and labels (without consuming any space in the target calculator).  This system could be used for both Flash cards and RAM cards.



Sharp CMOS SC61720D16 ESR-J CPU (4 bit)
Clock speed: 1.024 MHz

2.8 times faster than PC-1250(A) series.


16 alphanumeric character (5 x 7 dot) monochrome LCD,
contrast adjustment control.

Display symbols: BUSY, DEG, RAD, GRAD, E, M.

User Interface

Numeric keyboard.
Yes, No & Enter keys.
8 User-defined function keys for programs
Power off.
Card eject switch (also disconnects batteries).

Keyboard calculator functions

Addition, subtraction, multiplications, division, constant, percent, percent increase/decrease, power series, fraction, keyboard memory.

System Memory

System ROM (inside CPU): 14,224 10-bit steps.
System RAM provided with plug-in card, uses 850 bytes from RAM.

Program & Data Memory

This memory is provided by a card that fits into the back of the calculator.

There are two types of cards: Sharp RAM cards in the following sizes: 2K, 4K, 8K & 16K.

PROM CF-Series Flash cards in the following sizes:
      32K ROM + 8K RAM  (8K-page x  4)
      64K ROM + 8K RAM  (8K-page x  8)
    128K ROM + 8K RAM  (8K-page x 16)
    256K ROM + 8K RAM  (8K-page x 32)
    512K ROM + 8K RAM  (8K-page x 64)

BASIC Interpreter

Built into system ROM.  Very efficient 1-byte per token system maximizes storage.  See SBC Reference Manual for language reference.

Language is compatible with other Sharp PC calculators: PC-1245, 1246, 1247, 1250(A), 1251(H), 1255,  1252(H), & 1253(H), which can be used to develop programs.

Program Development

Programs can be developed for RAM cards only on a PC-1250A/PC-1251H calculator.

Programs were developed for RAM and Flash cards on a PC using PROM's SBC PC-1270 Development System.

Program Storage and Protection

Programs stored in a PROM CF-Series Flash card cannot be erased or read by any combination of keys on the calculator (a separate  product is required to program Flash cards).

Program stored in a Sharp RAM card can be erased by pressing the ALL RESET button.  There is a backup battery in the RAM card that will hold the program in memory when the card is removed from the calculator.

Numeric and String Storage

A-Z and numeric arrays hold floating point numbers stored in BCD with 10 significant digits and a range of 9.999999999 E +99 to -9.999999999 E -99.

BCD math results in exact calculations ideal for financial calculations.  Internal calculations are performed to 11 significant digits, and the result is adjusted to 10 digits before being stored in a variable.

A$-Z$ variables hold strings up to 7 bytes.
B$()-Z$() variables hold string arrays up to 255 elements.  String length is fixed within an array and can be set from 1 to 80 bytes (subject to memory limitations).

Arrays can be multi-dimensioned.

There are 25 arrays available for numbers, each with 255 elements, and another 25 available for strings, plus a special purpose array (A$()).


2 x CR2032 Lithium Batteries (2 x 3 v.)
Life:  Approx 120 hours of normal use at 20°C/68°F
Power consumption: 0.04W

Current draw (with CE-210M RAM card)
Power switch on: 275 µa;;  off: 7 µa

Automatic Power Off

If no key is pressed within about 10 minutes, the PC-1270 automatically is turned off.  Press the [CA] key to resume operation. No data is lost.

Operating Temperature

0°C to 40°C (32°F to 104°F)

W x D x H

135mm x 80mm x 9.5mm


85g including batteries

Included Accessories

Hard case
2 CR-2032 Lithium batteries
Operation manual

26 Jun 2014