Texas Instruments - Calculator - 1970-1980 - TI-1250 1970s LED memory

The Texas Instruments TI-1250 is an early-1970s electronic calculator, produced during a pivotal transitional phase in the history of electronic computation.
Belonging to the early pre-LCD era, this model features a red LED seven-segment display, a technology characteristic of first-generation portable electronic calculators, prior to the widespread adoption of low-power liquid crystal displays.
The TI-1250 represents Texas Instruments’ move toward compact, mass-market professional calculators, contributing to the standardisation of calculation logic, keyboard layout, and integrated memory functions that would later define modern electronic calculators.
At the time of its introduction, the inclusion of dedicated memory functions marked a significant advancement for office and professional environments.
The presence of the original box is particularly noteworthy, as packaging from this early period of consumer electronics was often discarded and rarely preserved, enhancing both historical documentation and collectability.
Technical Description
Manufacturer: Texas Instruments
Model: TI-1250
Period: Early 1970s
Technology: Early integrated electronic calculator circuitry
Display: Red LED, seven-segment, multi-digit
Functions:
Basic arithmetic operations
Memory functions (M+, M-, MR)
Keyboard: Mechanical push-button keys with individual contacts
Power supply: Battery operated (pre-LCD, high-consumption technology)
Dimensions: approx. 13.8 × 7.0 × 3.5 cm (approx. 5.5 × 2.8 × 1.4 in)
Original box included
All frontal inscriptions and markings are clear and legible.
Functionality and Tests Performed
The calculator has been fully tested and is in working condition.
Memory function test procedure:
Entered 50, pressed M+ to store the value in memory
Cleared the display using C
Pressed MR → display correctly recalled 50
Entered 25, pressed M+
Pressed MR → display correctly showed 75
Entered 10, pressed M-
Pressed MR → display correctly showed 65
These tests confirm that the memory functions (M+, M-, MR) are fully operational.
The LED display is stable and clearly readable, and all keys respond correctly.
Internal Inspection Notes
The internal components have been visually inspected.
The calculator features an original early LED display module with individual optical lenses, consistent with early-1970s electronic calculator technology.
The internal circuitry and keyboard mechanism appear original, with no visible signs of modification or repair.
The internal construction reflects early integrated electronic design, prior to the widespread adoption of fully encapsulated display modules and membrane keyboards.
Condition
Fully functional
Memory tested and confirmed working
Original box included
Normal signs of age consistent with period
No restoration or modification performedThe item offered is original, vintage, and pre-owned, and is described accurately and in good faith.
Before listing, the item is carefully cleaned, tested, and documented with detailed photographs and. All functions mentioned in the description are tested and verified and are tested again before shipment as a final quality check.
Photographs form an integral part of the description and accurately represent the condition of the item at the time of listing.As this is a vintage item, minor signs of age and normal wear are to be expected and are consistent with its age. Any structural damage, missing parts, or non-functioning features are clearly disclosed in the description and/or visible in the images. Colours may vary slightly due to lighting conditions and screen settings.
The item will be professionally packed using protective materials, and double-boxed where appropriate. Shipping is tracked and insured. The item is handed over to the carrier in the same condition as documented prior to dispatch. This is a vintage electronic item. Due to its age and original components, slight variations in performance, accuracy, or behaviour may occur over time, even if fully functional at the time of testing.
The item has not been modified unless explicitly stated and is intended for normal use consistent with its age, or for collection and display.
By placing a bid, the buyer confirms that they have carefully read the description and reviewed all images.