Parallel

From uCtrl.net

Contents 1 Information 2 Connection 2.1 Inputs 2.2 Outputs 3 Contacts 3.1 25-Pin 3.2 36-pin Centronic 3.3 Printer cable 4 Resources 4.1 Files 4.2 Links

Information

The parallel port is commonly known as the computer printer port, it uses two addresses, one for inputs (e.g. 887) and one for outputs (e.g. &h378). Inputs can be connected using a resistor to GND and the outputs using a NPN transistor with a pre-resistor.

Connection

Inputs

Pin D-Sub 25	Pin Centronics	SPP Signal	Input
10	10	nAck	4
11	11	Busy (Inverted)	5
12	12	Paper-Out/End	3
13	13	Select	2
15	32	nError/nFault	1

Outputs

Pin D-Sub 25	Pin Centronics	SPP Signal	Output
2	2	Data 0	1
3	3	Data 1	2
4	4	Data 2	3
5	5	Data 3	4
6	6	Data 4	5
7	7	Data 5	6
8	8	Data 6	7
9	9	Data 7	8

GND is in pin 18 trough 25 on the d-sub, and 19 trough 29 on the centronics.

Contacts

25-Pin

1. Strobe (out)
2. Data bit 0 (out)
3. Data bit 1 (out)
4. Data bit 2 (out)
5. Data bit 3 (out)
6. Data bit 4 (out)
7. Data bit 5 (out)
8. Data bit 6 (out)
9. Data bit 7 (out)
10. Acknowledge (in)
11. Busy (in)
12. Paper out (in)
13. Select (in)
14. Autofeed (out)
15. Error (in)
16. Reset (out)
17. Select (out)
18. Signal ground
19. Signal ground
20. Signal ground
21. Signal ground
22. Signal ground
23. Signal ground
24. Signal ground
25. Signal ground

36-pin Centronic

1. Strobe (out)
2. Data bit 0 (out)
3. Data bit 1 (out)
4. Data bit 2 (out)
5. Data bit 3 (out)
6. Data bit 4 (out)
7. Data bit 5 (out)
8. Data bit 6 (out)
9. Data bit 7 (out)
10. Acknowledge (in)
11. Busy (in)
12. Paper out (in)
13. Select (in)
14. Autofeed (out)
15. Select IN
16. Logic Ground
17. Shield Ground
18. +5 V DC (50 mA max)
19. Signal Ground
20. Signal Ground
21. Signal Ground
22. Signal Ground
23. Signal Ground
24. Signal Ground
25. Signal Ground
26. Signal Ground
27. Signal Ground
28. Signal Ground
29. Signal Ground
30. Reset Ground
31. Reset (out)
32. Error (in)
33. 0 V
34. Not used
35. +5 V DC
36. Select (out)

Printer cable

Line	DB25 han (PC)	Rettning	Centronics (printer)
Strobe	1		1
Data bit 0	2		2
Data bit 1	3		3
Data bit 2	4		4
Data bit 3	5		5
Data bit 4	6		6
Data bit 5	7		7
Data bit 6	8		8
Data bit 7	9		9
Acknowledge	10		10
Busy	11		11
Paper out	12		12
Select	13		13
Autofeed	14		14
Error	15		32
Reset	16		31
Select	17		36
Signal ground	18		33
Signal ground	19		19 + 20
Signal ground	20		21 + 22
Signal ground	21		23 + 24
Signal ground	22		25 + 26
Signal ground	23		27
Signal ground	24		28 + 29
Signal ground	25		16 + 30
Shield	Cover		Cover + 17

Resources

Files

• Parout-1.0.tar.gz (controlling parallel port outputs in linux)

Links

• Parallel I/O module
• Parallel cables
• Wikipedia article
• Parallel Port Prototypes