| Number | Name | Date | Kind |
|---|---|---|---|
| 4669053 | Krenz | May 1987 | |
| 4725244 | Chewning et al. | Feb 1988 | |
| 4769764 | Levanon | Sep 1988 | |
| 4862327 | Ansell et al. | Aug 1989 |
| Number | Date | Country |
|---|---|---|
| 2143117 | Feb 1985 | GBX |
| Entry |
|---|
| "Industrial Personal Computer for Class C Industrial Environment", IBM Technical Disclosure Bulletin, vol. 28, No. 7, Dec. 1985, pp. 2785-2798. |