Number | Date | Country | Kind |
---|---|---|---|
63-240981 | Sep 1988 | JPX |
Number | Name | Date | Kind |
---|---|---|---|
3916177 | Greenwald | Oct 1975 | |
4390953 | Johnstone | Jun 1983 | |
4520233 | Smith | May 1985 | |
4695946 | Andreasen | Sep 1987 | |
4766548 | Cedrone | Aug 1988 | |
4823290 | Fasack | Apr 1989 | |
4823343 | Takahashi | Apr 1989 | |
4829560 | Evanyk | May 1989 | |
4893248 | Pitts | Jan 1990 | |
4962449 | Schlesinger | Oct 1990 | |
4974255 | Defay | Nov 1990 |
Number | Date | Country |
---|---|---|
61-6426 | Feb 1986 | JPX |
61-250715 | Nov 1986 | JPX |
62-95621 | May 1987 | JPX |
62-134750 | Jun 1987 | JPX |
1140260 | Jun 1989 | JPX |
Entry |
---|
Telecommunications, Apr. 1986, "ITT Security Modem", p. 101, vol. 20, No. 4. |
Electronics, Mar. 1984, "Call-Back Schemes Ward off Unwanted Access by Telephone", pp. 131-135. |
IBM Program Announcement, Jun. 16, 1987, Information Systems Group, North-Central Marketing Division, South-West Marketing Division, pp. 287-235 through 287-237. |