The MZ-80c is based on the MZ-80K, but offers some enhancements to match the professional market of that time. The price was improved too ;-) It was the first MZ-80 computer to be delivered assembled as opposed to first MZ-80k which were sold as kits.
The RAM size is now of 48 KB. The keyboard which was so strange on the MZ-80K because of its matrix organisation, has now a more common layout with a large spacebar key. The numeric keypad is separated.
Another major change is that the monochrome monitor now displays black & green instead of black & white. Useful addons were available such as a disk-drive, a printer and a color & graphic expansion unit (PCG).