I designed the CA80 from scratch. Initially, I used SMD, but I changed the assumptions and adapted the project to RCbus. I used the Z80-MBC2 project and with its help I developed an additional data loader. I also made an additional mass memory module that stores programs in flash memory. The data format is compatible with that recorded on the tape recorder. LCD 2004 modules and a touch keyboard were also created. I also have a VFD display and a keyboard from an old calculator.