I have a set of the system disks available from Daves Old Computers - System / Install Disks. These are revision 1.1 of the 1050 BIOS for CP/M 3.

Does anybody have a later BIOS revision that could share? I am looking for a version that had support for an external hard drive off the winchester port, e.g. the presence of the file WINCH.ASM on the BIOS source disk would indicate this.

I know revision 1.3 had this support, not sure about other versions.