| Number | Name | Date | Kind |
|---|---|---|---|
| 3508356 | Ross | Apr 1970 | |
| 3701869 | Jacob et al. | Oct 1972 | |
| 3965599 | Ebner | Jun 1976 | |
| 4066850 | Heys, Jr. | Jan 1978 | |
| 4101884 | Benton, Jr. | Jul 1978 | |
| 4119839 | Beckmann et al. | Oct 1978 | |
| 4126855 | Alms et al. | Nov 1978 | |
| 4336530 | Koike et al. | Jun 1982 | |
| 4439757 | Gross et al. | Mar 1984 | |
| 4684940 | Charmeux | Aug 1987 |
| Number | Date | Country |
|---|---|---|
| 742756 | Jan 1956 | GBX |
| Entry |
|---|
| IBM Technical Disclosure Bulletin, "Keyboard with Changeable Encoding and Key Designation", vol. 13, No. 7, 12-1970. |
| IBM Technical Disclosure Bulletin, "Interchangeable Keyboard Character Indicator", vol. 14, No. 8, 12-1970. |