An Exidy Sorcerer ROM-PAC diagnosis

Ok, progress on checking out this Sorcerer BASIC ROM-PAC.. I diescovered there was no way you could exit to the monitor program if you had a hung ROM-PAC plugged in BUT....I figured out a way to check the content of the ROM-PAC ROMS. In the Sorcerer the ROM-PAC occupies space from C000-DFFF using 4 chips. Reading the docs I saw that the boot up sequence jumps to DFFD or DFFA depending on if it's a warm or cold start. However, if it finds nothing there, it assumes there is no ROM PAC attached and boots up the monitor. YES! This means all I needed to do is remove the number 4 IC (D800-DFFF) and I should be able to boot to the monitor and then examine the contents of the three lower ICs. I could then substitute the number 4 IC for one of the lower ones and examine its contents too. I removed the number 4 chip, plugged in the ROM-PAC and booted. Success, I was in the monitor. I then dumped the memory locations corresponding to the ROMS. The two lower ICs (C000-CFFF) showed all different hex numbers. In other words it looked like it contained good code. However, the third IC (D000-D777) contained all zeros!! I then swapped over the D800-DFFF chip I'd removed into the socket which originally contained the D000-D777 and checked that number 4 chip. The code looked good and I could even see the bootstrap code at the end at DFFD and DFFA (of course it was at location D7FD and D7FA as I had this number 4 chip in socket 3). Conclusion. It's the number 3 IC which is faulty. Next task. Unpack the EPROM burner and try to figure out how to use it.