Brief history of Híradástechnika calculators

Híradástechnika Szövetkezet (Telecommunication Cooperative) was established in 1951. They manufactured mainly measuring and testing equipments for televisions, and CCTV systems. The EMG (Electronic Measuring equipments Factory) was the only hungarian corporation who produced calculators in the early 1970s. Their models became obsolete at this time, but they planned pocket calculators from 1971. Due to burocracy and restrictions of the socialist system, these pocket calculators had been never produced. The first types of Hunor 85/86 pocket-sized calculators announced only in 1975/76 for a very high price comparing to other similar models. So in the early 1970s, there was a need for producing pocket calculators. Híradástechnika and Bowmar/Ali Inc. in Canada established a cooperation company called HírBow for producing licensed calculators in Hungary, mainly from imported parts. A new plant was in construction in Balatonlelle, which was decided to make calculators from 1974. At the Budapest International Fair '73, HírBow announced three types of pocket calculators and a desktop model. Interestingly, Hewlett-Packard announces their first scientific model (HP-35) in the same fair. Both were big success, so Híradástechnika started to assembly calculators from 1973.

Most popular HT calculators
Top: K-832 (1974), TK-1023 (1976), TK-1024 (1977)
Bottom: PTK-1072 (1977), PTK-1050 (1980), PTK-1096 (1978)

Belonging to this cooperation, the first calculator using algebraic logic (K-832) and the first scientific model (TK-835) were issued in 1974. These were the last produced Bowmar models due to bankruptcy of Bowmar/Ali Inc.

In 1975, a new supplier was found: General Instrument Corporation, which manufactures calculator chips and in this time, complete calculators too. A new four-function basic calculator was planned and built from parts (K-841), and the EZ-3500 scientific model (TK-891) were started to assemble at Balatonlelle. Inaccuracy, insufficient capacity and lack of some widely used functions made this scientific calculator unpopular. From 1976, National Semiconductor calculators with Reverse Polish Notation logic was produced: the first two models (TK-1023, ant the programmable version, PTK-1023) was originally an entry-level scientific calculator, the last (TK-1024) became one of the most reliable calculators of the HT family.

From 1978 to 1980, Commodore's most powerful programmable model and its OEM variants with and without programming capabilities were sold under the series PTK-1072. In 1977, Texas Instruments announced a new product line including three programmable calculators, these were added to the PTK line in 1979-80: the SR-51-II (US version: TI-55) as PTK-1030, the TI-57 as PTK-1050 and the TI-59 as PTK-1096, which has an optional cradle and printer KA-100 (PC-100A). The successors of the TI-57 had not been rebranded, these were sold with original model numbers: TI-57 LCD in 1984, and TI-57-II in 1985, which was the last calculator assembled by Híradástechnika.

Note that a SHARP-licensed pocket computer (PTA-4000) with a printer and cassette interface (KA-160) were manufactured by Híradástechnika from 1983.

Table 1: Híradástechnika calculators from 1973 to 1985

Model	Year	OEM	Type	Capacity	Logic	Memory	Display	CPU
K-83	1973	Bowmar 905	pocket	8	arithmetic	-	LED	Texas TMS0103NC
K-86	1973	Bowmar 901B	pocket	8	arithmetic	-	LED	Texas TMS0103NC
K-106	1973	Bowmar 901D	pocket	10	arithmetic	-	LED	Texas TMS0107NC
K-831	1973	Bowmar MX-50	pocket	8	arithmetic	-	LED	Rockwell 15332PC
A-100	1973	Bowmar TX-1000	desktop	10	arithmetic	-	Panaplex	Texas TMS0107NC (?)
K-106 P	1974	Bowmar MX-80	pocket	10	arithmetic	-	LED	Texas TMS0127NC
TK-835	1974	Bowmar MX-140	pocket scient.	10+2	algebraic	1	LED	MOS MCS2525-001 + MCS2526-001
K-832	1974	Bowmar MX-55	pocket	8	algebraic	-	LED	IDT LC1552B
TK-891	1975	General Instruments EZ3500	pocket scient.	8/5+2	algebraic	1	LED	GI C-596-1
K-841	1975	-	pocket	8	algebraic	1	LED	GI C-594
TK-1023 (TK-891-1)	1976	NOVUS 4520	pocket scient.	8+2	RPN	1	LED	NSC MM5758N
PTK-1023	1976	NOVUS 4525	pocket prog. scient.	8+2	RPN	1	LED	NSC MM5758N + MM5766N
TK-1024	1977	National Semiconductor 4640	pocket scient.	10+2	RPN	3	LED	NSC MM5782N + MM5751N
PTK-1060	1977	Elektronika B3-21	pocket prog. scient.	8+2	RPN	8	LED	K145IK501P + ..502P + ..503P
PTK-1072	1977	Commodore PR-100	pocket prog. scient.	8+2	algebraic	10	LED	MOS MPS7530-201 + MPS7543-001A
PTK-1030	1977	Texas Instruments SR-51-II	pocket prog. scient.	8/5+2	AOS	8	LED	Texas TMC1503
PTK-1096	1979	Texas Instruments TI-59	pocket prog. scient.	10+2	AOS	100	LED	Texas TMC0501E
PTK-1072-1	1979	APF Mark 90	pocket prog. scient.	8+2	algebraic	10	LED	MOS MPS7530-201 + MPS7543-001A
TK-1072-1	1977	APF Mark 56	pocket scient.	8+2	algebraic	10	LED	MOS MPS7530-201
PTK-1050	1980	Texas Instruments TI-57	pocket prog. scient.	8/5+2	AOS	8	LED	Texas TMC1501NL
TI-57 LCD	1984	Texas Instruments TI-57 LCD	pocket prog. scient.	8/5+2	AOS	8	LCD	Texas TP0456NL + CD4555BNL
TI-57-II	1985	Texas Instruments TI-57-II	pocket prog. scient.	8/5+2	AOS	8	LCD	Texas CD4572BN2 + CD4555BN2

Abbrevations: scient. = scientific, prog. = programmable, RPN = Reverse Polish Notation (with stack), AOS = Algebraic Operating System by Texas Instruments. In the row Capacity, number following the + sign was the capacity for exponent. Capacities with a slash: the first number is for the normal, the second is for scientific display mode.

Thanks to Attila Piros for informations about the TI-57-II.

K-831 (1)

1973