Texas TI-66 Programmable: Toshiba skills to rescue Texas...

[jebem]

So I saw this nice Texas TI-66 Programmable calculator for sell in one of our local auction sites, complete with documentation, pouch, and original packaging.
The asking price was so low that I could not resist myself to acquire yet another machine, even if it is coming from the dark side (I wonder why Texas is refereed as such in a few forums?)

The calculator itself is near mint condition, just showing tiny scratches here and there.
The manual is as new, probably never used, and the packaging is in excellent condition.

It seems that this calculator was outsourced to Toshiba. The main PCB has the Toshiba label screened to the copper layer and the SoC chip is a Toshiba T6875A from 1986.

The memory chip is a 1024 x 4-bit words CMOS static RAM TC5514AP-3 in a DIP-18 package from 1985.

As usual for machines that are not sealed (unlike many HP models using plastic rivets to seal the case and taking the fun away from this hobby), I have dismantled it piece by piece for inspection and cleaning.

To open the case it is enough to remove one single screw from the back cover.
To remove the pcb it is enough to remove a few screws.

One excellent engineering solution found by Toshiba is the LCD display connection to the main PCB - a metal bracket is used and maintained in place using 3 screws.
This method is efficient and expensive to manufacture, so Texas/Toshiba didn't cut costs here.

Another excellent feature are the costly injection molded keys. Considering that in the 80's most of the manufacturers were using painted keys, this is a nice touch from Texas.








Edit:
Here is a review in the Eddies's Math And Calculator blog

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