mainly is possible to install a normal QL board in the case, you only need to take care that original power supply conector do not have a hole in the case and the keyboard.
* The TOP board is a unmodified QL board, or perhaps minimun modifications, CPU and ROM can be removed if used the 68020 board.
* The 68020 CPU + ROM board is not mandatory, you can have the normal 68008.
* The Power Supply is a +5v, +12v, -12v, all DC and stabilized , it need to supply to the aditional boards and disk drives, a Spectrum +2A or +3 can be replacement in case of emergency.
* The "Back Plane" is a expecial one, you can not connect anything to the botton conector, because it wire the signals in a diferent way, and it do something similar to the Qplane, where supply +5V to the QL and other boards without use the internal regulator.
* The botton PCB is a sum of other boards, something similar to 512Kb of RAM + SCSI interface + Floppy Disk Interface + PS2 keyboard + QIMI like Mouse + ICE + Roms in the free memory area, CST sell some of this previously as separate boards. as a note it provide the correct voltajes on the expansion slot, so not need to do modifications like in qplane.
Should be posible to create a new backplane that allow to conect a 512k Kb ram + Qubide + CST Floppy + ICE cartridge and you will have some similar to a CST Thor 20, lack of the expansion board and the aditional ROM, but nowday is posible to load exchange from a hardisk, the main problem is the keyboard. a diren interface or something similar is need.
This seen to be a good project for a future
