First Alert T-1000 Parallel Interface

Technical Specifications

Parallel Interface

Connector pin assignments and a description of respective interface signals are shown below and on the following page.

Signal	Return
Pin	Pin	Signal		Direction	Description
1	19			IN		pulse to read data in. Pulse
		STROBE			STROBE
					width must be more than 0.5 µs at the
					receiving terminal.
2	20	DATA 1		IN	These signals represent information of
3	21	DATA 2		IN	the 1st to 8th bits of parallel data,
4	22	DATA 3		IN	respectively. Each signal IS at HIGH level
5	23	DATA 4		IN	when data is logical 1 and LOW when it IS
6	24	DATA 5		IN	logical 0.
7	25	DATA 6		IN
8	26	DATA 7		IN
9	27	DATA 8		IN
10	28			OUT	Approximately, 12 µS pulse.
		ACKNLG
					LOW indicates that data has been
					received and that the printer is ready
					to accept more data.
11	29	BUSY		OUT	A HIGH signal Indicates that the printer
					cannot receive data. The signal goes
					HIGH in the following cases:
					1) During data entry (ea. char. time)
					2) During printing
					3) When off line
					4) During printer-error state.
12	30	PE		OUT	A HIGH signal indicates that the printer is
					out of paper.
13					Pulled up to +5 V through 3.3 K
					resistance.
14		AUTO		IN	When this signal is LOW, the paper is
		FEED XT			automatically fed 1 line after printing.
					(The signal level can be fixed to this by
					setting DIP switch 2-4 to ON.)
15	-	NC	-		Unused.

Technical Specifications 6-5