The TK-80 was an 8080-based single-board computer kit developed by Nippon Electric Company in 1976. It was originally developed for engineers who considered using the μCOM-80 family in their product. It was successful among hobbyists in late 1970s in Japan, due to its reasonable price and an expensive computer terminal not being required.
History
In February 1976, NEC formed the Microcomputer Sales section in the Integrated Circuit division, and began to provide development environments for their microprocessors. However, they visited customers and explained, but it was difficult for them to understand how to use a microprocessor. At the same time, NEC received an order from a laboratory in the Yokosuka Communication Institute of NTT that they wanted an educational microcomputer product for their new employees. Tomio Gotō, a member of the section, proposed to his manager Kazuya Watanabe developing an educational kit. Goto mainly designed the TK-80, and Akira Katō did the detailed design work. Goto got an idea from a photo of the KIM-1. The KIM-1 can monitor and show the current address by the software, but the display disappears when the CPU is hanging. The TK-80 has the Dynamic Display using the 555 timer IC and interrupt the CPU, it can always show the current address. In addition, the TK-80 has a CMOS battery. He decided to document its manual with a circuit diagram and assembly code of the debug monitor, influenced by the PDP-8 which was an open architecture and was used as an IC tester at NEC. at Bit-INN The TK-80 came out on August 3, 1976. It was priced at 88,500 yen, an engineer's section manager could approve at that time. NEC had opened a support center at the Akihabara Radio Kaikan on September 13, 1976. They found many machines were sold to not only electrical engineers but also businessmen, hobbyists and students. The TK-80 was sold more than 2000 units per month, despite 200 units expected. Soon after its success, other Japanese microprocessor manufacturers developed an evaluation kit for their microprocessor. Power supplies and other peripherals came out from third parties. Watanabe and his members wrote an introductory book Mi-com Introduction in July 1977, it became very popular and sold more than 200,000 copies. Also, some computer magazines were founded, the ASCII, the :ja:I/O |I/O, the Monthly Mi-com and the :ja:RAM |RAM. In Japan, the Altair 8800 was sold in 1975, but not successful due to its high brokerage fee. Neither the Apple II nor the Commodore PET. Single-board computers had been popular until the successor PC-8001 came out in 1979.
Variants
The TK-80E was a cost-reduced version priced at 67,000 yen, introduced in December 1977. It contained the NEC μPD8080AF, fully compatible with the Intel 8080A.. Other specifications included 768 B of ROM, and 512 B of RAM. The TK-80BS was introduced in December 1977. It included a keyboard, a backplane and an expansion board for the TK-80 with 5KB RAM and 12KB ROM. It supported 8K BASIC. The COMPO BS/80 was a fully assembled unit of the TK-80BS, introduced in 1978. It was not a success because of its poor built-in BASIC and slow clock speed. The TK-85 was introduced in May 1980 and was the successor to the TK-80E. It contained the μPD8085AC processor and has a system configuration that is considered to some extent for compatibility with the TK-80. Other specifications included 2 KB of ROM, 1 KB of RAM, while the board size was 310 × 220 mm. It supported BASIC. The PDA-80 was a development platform for NEC's microprocessors. It had the μPD8080A processor, 8 KB of RAM, a teleprinter interface and a self assembler for its processor.
