Before John let me on to the Weller programming software, I found WinHex to split the files. While not intuitive, it did work and I was able to program the split ROMs with my other programmer.
Well, I had some minor success with this. I modified the 8086 monitor slightly to use different console I/O bits in routines CO and CSTS. I get the monitor banner so the output is fine. The monitor doesn’t accept any character input (it echos with “?” and rings the bell).
The monitor also complains that it can’t find the 8259 PIC. When I did the testing during the build, it passed so I don’t know what’s up there.
Since the EPROM section is working at least, I may try to program the original SCP monitor program and see if that works.