IBM PS/1 type 2133/2168 ROM

Dumped from a 2133-540, 486SX-25, VLB CL-GD5424
IBM P/N 65G9498, dated 21/11/93

Compatible with PS/1 2168 models with the same system board, like the 2168-552.

Modified by Major Tom (https://www.ardent-tool.com) to enable the internal and external system caches when a 486 DX4ODP75 or DX4ODP100 CPU is installed on the CPU upgrade socket.
