PC LP'T- (Line PrinTer ).
, /. , 386h, 378h 278h. 8- , 5- 4- .
BIOS LPT- (LPT1-LPT4) INT 17h, Centronics. BIOS , , .
Centronics
Centronics , 36- , . . 1.
1.
Centronics
| I/O* | |||
| Strobe | I | . | |
| Data [0:7] | I | 2-9 | . Data 0 ( 2) |
| Actt | Acknowledge ( ). | ||
| Busy | . | ||
| PaperEnd | |||
| Select | |||
| Auto LF# | I | . | |
| : , OFF-Line | |||
| Imt# | I | ||
| Slot In# | I | ( ). | |
| GND | - | 19-30 33 | |
| * I/O | (/) . |
Centronics , -.
LPT-
SPP (Standard Parallel Port) , Centronics. #. DB-25S (), ( ) . (. 2) Centronics.
2.
LPT-
| DB-25S | ||||
| I/O* | Reg.Bit** | |||
| 0/1 | CR: 0\ | Strobe# | ||
| 0(1) | DR:0 | Data 0 | ||
| 0(1) | DR: 1 | Data 1 | ||
| 0(1) | DR: 2 | Data 2 | ||
| 0(1) | DR:3 | Data 3 | ||
| 0(1) | DR: 4 | Data 4 | ||
| 0(1) | DR:5 | Data 5 | ||
| 0(1) | DR:6 | Data 6 | ||
| 0(1) | DR:7 | Data 7 | ||
| I | SR: 6 | Ack# | ||
| I | SR: 7\ | Busy | ||
| I | SR: 5 | PaperEnd | ||
| I | SR: 4 | Select | ||
| 0/1 | CR: 1\ | Auto LF# | ||
| I | SR: 3 | Error# | ||
| 0/1 | CR: 2 | Init# | ||
| 0/1 | CR:3\ | Select In# | ||
| 18-25 | 10, 12, 14, 16 | 18, 20, 22, 24, 26 | - | - |
|
|
|
* I/O (/) ; 0/I , .
** \ (1 ).
*** Ack# (10 ) +5 .
8- , /, (BASE).
Data Register (DR) , = BASE. , , . , , , .
Status Register (SR) , 5- ( SR.4-SR.7), = BASE+1. SR.7 , .
Control Register (CR) , =5+2. , 4- ( 0-3), . . , 1, 3 , .
( IRQ7 IRQ5) 10 (#) CR.4=1. , .
Centronics ( ):
(1 IOWR#).
( SR.7 BUSY).
, (2 IOWRff).
12 ( ), , 5 . , Nibble Mode. , Hewlett Packard Bitronics, 4 , .
