Early
Electronic
Calculator		 Texas Instruments TI-2550 Calculator

Manufacturer: Texas Instruments
Model: TI-2550
Year: 1975
Form: Pocket
Functions: Basic four, memory, percent
Number of Digits: 8
Display Type: LED
Logic Technology: LSI
Diodes: 11
Transistors: 5
IC Complement:Texas Instruments TMS 0601 NC
Texas Instruments SN75493 (2)
ITT (?) 27914 (2)
(5 total)
Batteries: 3 AA NiCd or 4 AA
Power Connector:8.2 VAC, sub-mini audio
(alternate/no batteries: 6 VDC, + tip)
Tech. Data Level: 2
Tech. Data Source: RE
Tech. Data Pages: 1
Tech. Data:Schematic (pdf)

- Unit Log -

Serial Number: 618408
Year of Manufacture: 1975 (TMS0601 IC stamped with 7536.)
Accessories: With carrying case and manual.
Date of Receipt: 02 May 2001
Source: Main & 12th second-hand store.
State upon Receipt: Good physical condition. Segment 'a' of digit 6 does not work. Minor corrosion on battery terminals. This unit uses 75494 digit driver ICs also stamped with 27914. The 75493 segment drivers are absent.
Current State: Fully functional except for segment a of digit 6 (03 May 2001).

Date: 03 May 2001
Procedure: Cleaned. Battery terminals rewired. Faceplate reattached with double-sided tape.

- Unit Log -

Serial Number: 365091
Year of Manufacture: 1975 (TMS0601 IC stamped with 7505.)
Accessories: With box, carrying case, manual and power adapter.
Date of Receipt: 13 May 2001
Source: Burnaby/Hastings flea market.
State upon Receipt: Good physical condition. Segment b of digit 8 (MSD) does not work. Minor corrosion on battery terminals.
Current State: Fully functional except for segment b of digit 8 (16 Mar 2002).

Date: 16 Mar 2002
Procedure: Cleaned.


  Texas Instruments TI-2550
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EEC 		bhilpert