This information was originally composed by Reginal Cross. He also summarized the 264 article in the CMD Issue #9, Vol 2 Number 4:
The series was originally to be the 264 and 364. They had 60K to basic, and 64K RAM total. This was a very good ratio, and was obviously done by having bank switching between ROM and RAM. They ran on a 7501 or 8501 CPU, which was 6502/6510 compatable. The heart of this line was the TED, or Text Editing Device. It comprised 320 x 200 Pixels, and text of 40 x 25. It had 128 color settings; 121 colors actually (8 blacks). It was made of 16 colors each with 8 luminance settings. The sound, as with the VIC-I used on the VIC-20, was integrated into the graphics chip, and consisted of 3 voices; 2 sound & one noise. Basic was upgraded quite a bit, and new easier to use disk commands were integrated into the new BASIC 3.5, as well as windows, and the graphics commands the C=64 so desperately needed. Also they included TEDmon, a machine language monitor in ROM to write and debug programs.
The plan changed and the 264 became the plus/4, integrating the 4-in-1 software by TRI-Micro including a word processor, spreadsheet, graphing tool, data manager. These applications were not much more than barely usable. The 364 project was scrapped and the lower-end C=16 and C=116 were produced. The C=16 looked like a black ViC-20, and the 116 was a C=16 with a chicklet keyboard in a plus/4 case. They had a shameful 16k of RAM, with only 12k usable by BASIC. This was, however, a better ratio than the VIC-20, with only 3k to BASIC. The C=16 and 116 had no user port; thus no communications or parallel devices. These machines were to target business use, since the C=64 and VIC-20 had strayed from the original Commodore Business Machines goal of business computers.