Zida Tomato BIOSes for Socket 7
Socket 7 (321pin) is a physical and electrical specification for an x86-style CPU socket on a personal computer motherboard. It was released June 1995. The socket supersedes the earlier Socket 5, and accepts P5 Pentium microprocessors manufactured by Intel, as well as compatibles made by Cyrix/IBM, AMD, IDT and others.
See: https://en.wikipedia.org/wiki/Socket_7.