CPT 4200 Wordprocessor, implemented in TTL (opens in new tab)

I’ve been delving into CPT machines recently, and found the CPT4200 from the early 1970s. It is a console that attaches to a modified IBM Selectric typewriter and allows text to be saved and loaded on one of two cassette tape drives in the 4200. The text can then be edited and reprinted as required from the tape. The second tape can be loaded with text as well, for example names and addresses, and the two combined and printed out, giving a mail-merge facility. This machine is implemented in T...