M/A-COM struggled financially themselves and sold the division in 1983 to Kendata Inc. of Trumbull, Connecticut, who immediately renamed it back to Ohio Scientific.

Kendata, previously only a corporate reseller of computer systems, failed to maintain Ohio Scientific's manufacturing lines and subsequently sold the division to AB Fannyudde of Sweden.

[10][9] The latter, called the Microcomputer Trainer Board and incorporating a MOS Technology 6502 microprocessor,[11] was designed by Mike, inspired by his experience with microprocessor-based minicomputers at his Ohio Nuclear job.

[5] Stan Veit, a business partner of Ohio Scientific as well as the founder of the first computer store in New York City, called the company poorly organized and hard to contact.

Chalmers beat out Chuck Kempton, a newly appointed marketing vice-president poached from Wang Laboratories, for the position.

While the company still operated as a subsidiary from its original headquarters in Aurora, the employees there soon became relegated to the status of a "support engineering group".

Spokespersons for the parent company cited M/A-COMM's decision to refocus on high-speed digital communications, as well as higher-than-expect costs of developing hardware and software for general-purpose computer systems.

[27] Kendata soon found themselves struggling to manage Ohio Scientific due a lack of technical and manufacturing prowess, however,[29]: D10  as well as dealing with stiff competition from IBM and Tandy Corporation.

[29]: D7  On October 3, 1983,[30] Ohio Scientific's Aurora's factory was shut down, and the inventory liquidated, after Kendata had foreclosed on the property.

[28] Kendata sold the remaining assets of Ohio Scientific to AB Fannyudde [sv] of Sweden in December 1983.

[35] Announced later,[36] but probably preceding the first Superboards in production, was the Model 300 Computer Trainer Board,[11] which features an MOS Technology 6502 microprocessor and 128 Bytes of RAM.

[37]: 94  In a design scheme similar to a number of trainer boards of its contemporary, a number of slide switches on the bottom of the board connect directly to the MOS 6502's data, read–write, and address select pins, allowing the microprocessor to be halted and the RAM loaded with machine code instructions.

[38] Ohio Scientific fully assembled each Computer Trainer Board, which came shipped with a manual; optional was a power supply and hardware and programming monographs.

[40][41] The Model 400 can be outfit with up to 1 kB of RAM, 512 Bytes of ROM, an ACIA chip for implementing RS-232 or 4–20 mA loop interfaces for serial communication, and a peripheral device adapter with 16 I/O lines.

The 430 Super I/O board provides two 8-bit DACs, one 8-bit ADC, an 8-bit parallel port, and a number of serial interfaces for terminal and teletype interaction and data storage, including Baudot, ASCII, FSK, and Kansas City standard.

This was a multiprocessor expansion board kit for the Model 400 Superboard that greatly expands its software library by supporting several different kinds of microprocessors, including the Intersil 6100 (a microprocessor-based implementation of DEC's PDP-8 minicomputer) and the Zilog Z80 (which is software-compatible with the Intel 8080 by design).

The 460Z supports only Model 400s running the 6502 but allows the latter to fully control the 460Z, including accessing each line of the 6100 and Z80 and setting those processors in either single-stepping mode or full-speed operation.

[45][46]: 98 If purchased with 4 KB of PROM, Ohio Scientific included a free roll of Microsoft BASIC on paper tape.

[45] In January 1978, Ohio Scientific began the Challenger I as part of an integrated bundle, including a custom video terminal using a Sanyo-manufactured CRT, a rebranded GSI 110 single floppy drive, and one of two Okidata dot-matrix printers.

[48] Kilobaud Microcomputing called the Challenger I "the first fully assembled mainframe computer which is priced competitively with hobby kits".

[46]: 99 [54] The Challenger IIP has an integral keyboard and RF video output board but only four of Ohio Scientific's semi-proprietary S-100 expansion bus slots.

[55] A later variant of the II proper includes the built-in cassette interface and video board of the IIP and came shipped with an external full-sized keyboard.

It supports dual drive configurations and sequential and random file access, while its BASIC implementation allows linked code.

[69] Ohio Scientific oriented the Challenger III as a development kit for students of computer science wanting to learn how to program for all three processor; as a small business or industrial machine, for organizations wanting to consolidate mission-critical applications for multiple platforms onto one unit; and for the extreme hobbyist.

To this end, Ohio Scientific provided a serial I/O board called the CA-10, allowing up to sixteen terminals to connect to the Challenger III.

[74][75] The company introduced it alongside the Challenger 1P, essentially the same as the Superboard II but enclosed in a case and including a power supply.

[80] As with the Challenger II, characters in the code page are redesignable, allowing for complex shapes to be drawn even in text mode.

[79]: 81  A "background mode" allows the user to run other applications in the foreground, while a timer resident in memory keeps track of X10 schedule and shuts appliances on and off accordingly.

The computer came stock with Microsoft 8K BASIC IN ROM, and 8KB of Static RAM, and it could have been expanded to have the home automation features of the 4P with the purchase of 630/10 expansion card.

The C1P MF was a variant of the computer that came packaged with a dual 5.25-inch floppy drive unit and OS-MDMS, a small database management system.