More calculators thinking Polish as a famous pioneer faces some rough competition

Only three short years ago, the HP-35 (featuring Reverse Polish Rotation) was introduced and soon won the praise and acceptance oof engineers everywhere at an initial $395. But on a struct cost/performance basis, the "veteran" of portable scientific calculators could be headed toward early retirement. Hewlett-Packard's latest pocket marvel, the scientific HP-21 at $125, retails $70 below the current price of an HP-35! Not only is the HP-21 cheaper, it also includes a degree/radian switch and handles inverse trig functions, two useful features its older brother lacks. Using fewer batteries and logic chips than any other H-P portable calculator, the HP-21 operates five hours on a full charge.

Contact Hewlett-Packard Co., 1501 Page Mill Rd., Palo Alto, Calif. 94304.

One calculator manufacturer just now entering the scientific arena is the Corvus 500 with a ten-digit mantissa and two-digit exponent display. Standard engineering functions are coupled wiht metric conversions, statistical capabilities, and easy transition between rectangular and polar coordinates. Like H-P, Corvus has chosen RPN for its scientific calculator. The Corvus 500, along with two other new calculators for business applications (Corvus 600 and 615) should now be entering the consumer market in quantity. The Corvus 500 lists for under $200, complete with rechargeable NiCad batteries.

For further information, write Corvus Corp., 13030 Branch View Lane, Dallas, Tex. 75234.

Also joining the RPN bandwagon are four new calculators from Novus, the consumer products arm of National Semiconductor Corp. Model 4510 at $69.95 features a three-level stack plus separate accumulating memory and an eight-digit LED display, but does not have scientific notation (keyboard includes trig, inverse trig, logs, exponents, and radian/degree conversion). A programmable version, Model 4515 at $139.95 has the same basic features as the 4510 combined with a learn-mode capacity of 100 steps.

A rollable four-level stack and scientific notation capability earmark Novus' Model 4520 at $99.95, and programmable Model 4525 at $169.95. While these two machines have no "dual-purpose" keys, they handle a full complement of scientific functions, excluding the degree/radian feature of their lower priced companions.

In every case, Novus' programmable calculators have a "delete" feature which allows correction of programs while they are being entered. All machines come with NiCad batteries and a charger.

Contact Novus, 1177 Kern Ave., Sunnyvale, Calif. 94086.

Meanwhile, Texas Instruments has bested its popular SR-50 calculator with the new SR-51. (Both machines feature algebraic entry.) Intended for scientific and statistical application, the SR-51 handles standard deviation, variance, linear regression, and factorials, in addition to its impressive slide-rule capabilities. The calculator also serves as a random-number generator, generating random two-digit numbers between 00 and 99. The SR-51's LED display is a 10-digit mantissa and two-digit exponent. Twenty commonly ised engineering conversions round out the SR-51's "can-do" list. Calculator, batteries, charger, and carrying case come complete for $224.95.

Need to know more? Write Texas Instruments Inc., P.O. Box 5012, MS 84, Attn: SR-51, Dallas, Tex. 75222.