Texas Instruments TI-30-II (First edition)

It took a long time to give the slimline calculators a similar keyboard like the original TI-30. Both the TI-25 and TI-35 introduced 3 years resp. 4 years before added some statistical functions not known on the TI-30.

Using the electronics of the European TI-30 LCD and the two shell housing of the TI-35 created this TI-30-II. Within one year this model was replaced with the stylistic enhanced TI-30-II sporting a different calculator chip.

If you dig deeper into the early slimline calculators you'll notice two different designs of the keys itself. The cheap looking keys like the ones on the left or the engraved keys started in the year 1978 with the TI-50. Some calculators used both keyboard:

In the year 1978 Texas Instruments introduced the first C-MOS calculator chips based on the TMS1000 Microcomputer family. The TP0320 architecture is similar to the TMC0980 chips introduced two years earlier for the TI-30 calculator. Main disadvantage of this family was the limited capacity with just 2k*9 bits ROM and 64*13 bits RAM resulting in simplified and sometimes inaccurate calculating algorithm.

The next generation of enhanced C-MOS calculator chips was introduced in 1981 with the TP0455 resp. TP0456 family. The second edition of the TI-30 II received during its production time an upgrade to the CD4565 chip which survived in the TI-35 II.

We discovered recently with the Sharp EL-503 a scientific calculator with the TP0327 single-chip calculator circuit, closing the missing link between the TP0326 located in the TI-38 and the TP0328 known from the Jeppesen Sanderson avstar.

If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, March 5, 2002. No reprints without written permission.