Number | Name | Date | Kind |
---|---|---|---|
2435130 | Cunningham | Oct 1944 | |
2484866 | Henry | Oct 1949 | |
4100402 | Lundstrom et al. | Jul 1978 | |
4769516 | Allen | Sep 1988 |
Number | Date | Country |
---|---|---|
2152437 | Aug 1985 | GBX |
Entry |
---|
Shelkofsky "Changeable Keyboard" IBM Technical Disclosure Bulletin vol. 21, No. 10 Mar. 1979 p. 4098. |