Hi Jim,
I no longer have a serial ThinkJet and I can only give you the information contained in the book related to the HP2225C Centronics printer.
It appears that the Centronics printer expects to be connected to HP, IBM or Apple IIe computers on the market at the time when the book was published in Nov. 1984.
DIP 5 switch has some special meaning and if in the HP mode, switch 5 should be down. If switch 5 is up, the printer is said to be in the Alternate Mode.
Switches 1 and 2 define the CR and LF action.
If 1 is up, CR does CR and LF. If 1 is down, CR does CR only.
If 2 is up, LF does CR and LF. If 2 is down, LF does LF only.
Switch 3 is perforation skip mode. Up, 1 inch skip; down, no skip.
Switch 4 is page length. Up, 12 inch. Down, 11 inch.
Switches 6, 7 and 8 control the character set.
6 down - 7 down - 8 down = Roman-8
6 up - 7 down - 8 down = USA ASCII
6 down - 7 up - 8 down = Swedish
6 up - 7 up - 8 down = IBM 8
6 down - 7 down - 8 up = French
6 up - 7 down - 8 up = German
6 down - 7 up - 8 up = UK
6 up - 7 up - 8 up = Spanish
Switch 5 seems to be software dependent, so I cannot give you very good instructions at this time.
Because I am old and living on borrowed time anyway (14 years), I will be placing my 4 HP-IL and 2 Centronics ThinkJet printers and my 15C, 16C, 75C, 41CX and much more on the on the market in the near term.
Hank - professorkscc@netzero.com