First Alert ACTION T-1000 - Manual (Page 83)

#8143 New Serial Interface Board
If you are using an optional interface, it may be necessary for you to
alter the communications protocol of the printer or the computer so they
can communicate properly. In most cases, you should use the
information in your optional interface manual or your computer’s
manual to match the computer with the interface.
For the #8143 optional interface board, use the DIP switch settings
shown below. These switches are on the interface board, not on the
printer.
#8143 DIP switch settings
DIP sw Function O N O F F
1 - 1 Selects baud rate See following table
1-2 Selects data length 7 bits 8 bits
1-3 Selects baud rate See following table
1 - 4 Selects baud rate See following table
1-5 Selects EVEN ODD parity EVEN O D D
1 - 6 Enables /disables parity check Enabled Disabled
1-7 Selects baud rate See following table
1-8 Enables/disables #8143 mode Enabled Disabled
Appendix A-9