7/28/2019 Texas TI-66 Datasheed

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Texas Instruments TI-66.

Datasheet

Years of production: 1982-1985? Display type: Numeric display

New price: Display color: Black

Display technology: Liquid crystal display

Size: 3"5"" Display size: 10(8+2) digits

Weight: 4 oz

Entry method:

Algebraic withprecedence

Batteries: 2"LR44" button cell Advanced functions: Trig Exp Lreg Cmem

External power: Memory functions: +/-//

I/O: Printer port

Programming model:Partially mergedkeystroke

Precision: 13 digits Program functions:Jump Cond Subr Lbl Ind

Memories: 64(0) numbers Program display: Mnemonic display

Program memory: 512 program steps Program editing:Auto-insert programentry

Chipset: Forensic result: 9.000002294775

After the failure of the infamous TI-88 project,

Texas Instruments was stranded without a product

that could meet the challenge represented by

Hewlett-Packard's amazing HP-41calculator. Thesolution was to seek help from other manufacturers.

The TI-66, an obvious successor to TI's hugely

popularTI-58/TI-59 product line, is a calculator

built by Toshiba, with Toshiba components inside.

A less ambitious machine than the HP-41, the TI-66

was nevertheless a quite capable device. Like the

HP-41, it offered an alphanumeric display; its

programming model, however, is very similar to that

of the TI-59. It lacked the HP-41's fabulous expandability, but it did have a proprietary serial port that

allowed it to be connected to the PC-200 printer. (The same port appeared on the BA-55.)

Up to 512 program steps or 64 memories are enough for many complex problems. The machine contained

numerous improvements over the TI-58C, which can be considered its closest predecessor with its

continuous memory. In addition to the low power alphanumeric display, the calculator offered mnemonic

display of program steps, a program entry mode that always showed the most recently entered step (as

opposed to the next, usually blank, program step), and a pleasant shape and appearance in a small form

factor. About the only drawback, when compared with the TI-58C, is the lack of a module port; gone were

the solid state software modules that made the TI-58/TI-59 machines so versatile. (Then again, those

modules were never as popular as they could have been, so perhaps TI had a solid reason for dropping this

feature.)

Internally, these machines reflect the bold new age of extreme simplicity: a single circuit board that alsoserves as the keyboard backplate, with two surface mounted chips and a couple of discrete components. It

was somewhat of a surprise to me when I realized that the machine's memory chip is an off-the-shelf

component in a large, easy-to-solder DIP socket. However, this made it possible for me to repair one of my

TI-66s that had a working processor but dysfunctional memory.