of VisiCalc development, Ed Esber, Roy Folk, Visi On's product marketing manager, among others. This was referred to as "corporate civil war". It was Mitch Kapor's departure that would prove most devastating to the company, however. Kapor, developer of VisiPlot and VisiTrend, had been pressing for the development of a greatly improved spreadsheet to succeed VisiCalc, but Opdendyk was uninterested. This was during a time when VisiCorp and VisiCalc's developers were at an impasse, and VisiCalc was growing increasingly outdated. When Kapor decided to leave, the other executives pressed for a clause forbidding Kapor to work on an "integrated spreadsheet", but Opdendyk couldn't be bothered, exclaiming Kapor is a spaghetti programmer, denigrating his abilities. Kapor would go on to release Lotus 1-2-3, which became a major competitor to VisiCalc in 1983. By the end of the year, sales had been cut in half. Combined with the exodus of major portions of the senior executive staff and the ongoing battle with VisiCalc's developers, VisiCorp was soon in serious financial difficulty. All hopes for the company's future were placed on Visi On. The October 31, 1983 InfoWorld, in an article titled, "Finally, Visi On is here," flatly stated: "the... publisher is putting the product on computer store shelves... Visi On was scheduled to be available during the last week in October". The November 14, 1983 issue said: "VisiCorp has just released Visi On." However, the July 2, 1984 issue says: "By the time Visi On was actually shipped on December 16, 1983,..." and PC Magazine reported in the February 7, 1984 issue that they still hadn't received the product in its commercially available form. Release The operating system, known as the Visi On Applications Manager, was released in December 1983 and sold for $495, requiring a mouse for another $250. Reception The main disadvantage of Visi On was its extremely high system requirements by 1982 standards. It needed 512 kilobytes of RAM and a hard disk at a time when PCs shipped with 64k-128k and IBM did not yet offer a hard disk with the PC (IBM's first model with a hard drive, the PC XT, didn't ship until March 1983). Third-party drives were however available at the time, typically 5MB units that connected to the floppy controller and were treated by the operating system as an oversized floppy disk (there was no subdirectory support). This brought the total cost of running