I don't know if it will help, but Ensoniq ESQ-1 cartridges have an signature in the 192 last bytes, not used by the parameters.
The EEPROM is 8k X 8 = 8192 bytes.
Each patch is 100 bytes long and the cartridge can store 80 patches using 8000 bytes from the memory.
The synth verifies these bytes to assure that the cartridge belongs to that model of synth, but you don't have access to modify these bytes through the synth.
You need an eprom programer to copy an existing cartridge to that one (all the bytes). Then you may use this cartridge as you want, assuming your cartridge and synth are working properly.
The SD-1 may be the same. I'm not sure.