The Texas Instruments TI-74 Basicalc is a type of programmable calculator, which was released in 1985 to replace the Compact Computer 40.

ManufacturerTexas Instruments
Introduced1985
TypePocket computer
ProcessorTMS70C46
TI-74 BASIC Pocket Computer PCB
TI-74 BASIC Pocket Computer CPU
TI-74 Info Card
TI-74 BASIC Pocket Computer With Case

The TI-74's architecture is descended from the never-released TI CC-40 Plus. TI utilized the CC-40 Plus ROM to create the TI-74's BIOS; it removed the CC-40's internal debugger to gain enough space to add calculator mode to the TI-74. The CC-40 Plus' cassette routines were reused in the TI-74, and the CC-40's Hexbus port underwent a physical footprint change and was renamed to Dockbus. The Hexbus protocol is 100% compatible between the CC-40 and TI-74 with an adapter.[1]

One variant, the TI-74S, has a blank faceplate instead of secondary functions to allow for customization (otherwise it is the same as the 74). Both models accepted customized ROM-modules. The TI-95, released at the same time, was a keystroke programmable descendant of the TI-59 and TI-66, with the same general form factor, but a two-line display (the second line was for function key definitions).

Technical specifications

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  • TMS70C46 CPU[2] (C70009, another chip from TMS 7000 family also reported)[3]
  • 31 5×7 character LCD
  • 32+4 KB ROM
  • 8 KB RAM
  • RAM/ROM memory expansion port
  • Hexbus port
  • 80 characters per line (31 visible)
  • powered by 4 AAA-size batteries

References

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  1. ^ Good, Charles. "A Compendium of CC-40 Information". WHTech TI-99 Archive. Retrieved 5 December 2022.
  2. ^ TI-74 BASICALC Technical Manual (PDF). Texas Instruments. 1987. Archived from the original (PDF) on 2013-07-15.
  3. ^ "DATAMATH CALCULATOR MUSEUM". Retrieved 22 December 2013.
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  • TI-74 on MyCalcDB (database about 1970s and 1980s pocket calculators)