CompuSource Compatible Systems Inc.^[1] was a short-lived privately held American computer company active in the 1980s and based in Minneapolis. It sold a variety of clones of the Apple II, including one portable that was also an IBM PC compatible and a CP/M machine.

CompuSource was incorporated in December 1982 and co-founded by Joel Ronning in Minneapolis, Minnesota. The computer's first product was a Apple II clone called the Orange Peel. Ronning commissioned original equipment manufacturer Orange Computers, out of Toronto, to manufacture the computer.^[2] It was able to run software for the Apple II but had slightly altered capabilities; as well, it used a custom ROM that was a clean-room design of Apple's BIOS for the Apple II.^[3]

Around 95 Orange Peel units worth US$76,000 were sold between late 1982 and early 1983,^[4] before the computer was the subject of a confiscation at the Minneapolis–Saint Paul International Airport in February 1983, when guards of the U.S. Customs Service seized four units from a cargo plane coming from Toronto. Executives of Apple had appealed to the Customs Service to look out for potential counterfeits of Apple's products in the years prior;^[5] almost 2,000 such counterfeits had been confiscated up to that point in total.^[2] Ronning stated that the Orange Peel did not contain any of Apple's copyrighted code nor infringed on Apple's trade dress, with an entirely different external appearance and detachable keyboard.^[6] Customs eventually cleared CompuSource of any wrongdoing in March 1984, calling the incident a mistake, but by that point Orange Computer had dissolved, and CompuSource moved on to another supplier. The company continued selling the remaining inventory of Orange Peels, at roughly $300,^[7] down from $795 in 1983 (both prices being a fraction of what Apple charged for their Apple IIs at the time).^[2]

Shortly after CompuSource lost its first appeal against Customs in August 1983, the company switched to a different supplier of hardware for their next family of clones. Called the Abacus, these computers were manufactured by General Fabrication Corporation of Forest Lake.^[8] The Abacus comprised both a standard desktop computer and a portable computer, the latter with a built-in 9-inch CRT monitor and keyboard. Both were compatible with software written for the Apple II and for CP/M; the company licensed Apple DOS 3.3 from Apple and CP/M 2.2 from Digital Research.^[9] Ronning was able to avoid charges of patent infringement by deviating from Apple's floppy controller card for the Disk II and schemes to generate artifact color on composite video signals.^[10]

Optional for both Abacus machines were a memory expansion card, a clone of the 80-Column Text Card, and an IBM PC compatibility card. The latter contained the circuitry needed to run software designed for the IBM PC running MS-DOS, including an Intel 8088 microprocessor. IBM compatibility was somewhat constricted by the Abacus' RAM ceiling of 192 KB.^[9] (CompuSource had been in negotiations with Microsoft to license MS-DOS for the computers but failed to get a contract by the computer's launch date.^[11]) The computers came with Compucalc, Compuword, and Compubase, spreadsheet, word processor, and database software respectively—all developed by ArtSci of Los Angeles—as well as three video games.^[12]

The Abacus portables were introduced to market in January 1984, with the first 100 units delivered to 100 different dealers for inspection that month.^[13] CompuSource achieved volume production around February, manufacturing around another 15,000 in the following months.^[14] The Abacus portables were optioned with one or two floppy drives; a 10-MB hard disk option was planned for mid-1984.^[15]