Microchess for the Kim-1 (2006)

> Microchess was sold for $10 per copy, in either US or Canadian currency; $12 for a copy that included a paper tape; and $13 for a copy on cassette tape.[9]

> Chuck Peddle, president of MOS Technology, offered to buy the rights to the game for $1,000, but Jennings refused to sell, believing his mail-order sales would make more.

> Over 1,000 copies of the game were sold by mid-1977, leading Jennings to quit his job and run Micro-Ware full-time. The game's success grew as Jennings released it for more microcomputer systems and the overall microcomputer market expanded. The game made Micro-Ware over $1 million by 1978, and was claimed in 1981 by Personal Software to have been the first computer program of any kind to do so.

> Microchess led to the creation of Micro-Ware, possibly the first software publishing company. In 1978, Micro-Ware merged with software publisher Personal Software, operated by Dan Fylstra, who had seen the game at the November 1976 show and bought the third-ever sold copy, with Fylstra and Jennings as co-owners. The resulting company, still named Personal Software, paid royalties to Jennings for Microchess, but Jennings soon funneled that money into funding the development of VisiCalc (1979), the first spreadsheet software. This led the company to rebrand as VisiCorp in 1982.

[1] https://en.wikipedia.org/wiki/Microchess

[2] https://en.wikipedia.org/wiki/1K_ZX_Chess

What hasn't changed is software taking up all the available memory!

I remember tying in hex during the 80s. What a relief when they started to add checksums and you knew you've made a typo in that hex data line.

http://www.6502.org/source/games/uchess/uchess.htm

Now THAT would be software to behold. No mention by the author as to whether the code of these emulators still exist.

The thing appears to have 128KB RAM and it can do time sharing... Impressive!