Virtual Museum of Calculators
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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 1984.

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
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.

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