B&B Electronics Parallel Port Input/Output Converter PPIO Benutzerhandbuch

6 

PPIO2899 Manual 

 

 
 

There are three port addresses that are normally used on a PC 

for parallel ports: 3BCH, 378H, and 278H. When your PC is reset or 
turned on these three addresses are scanned by the BIOS in the 
order shown above. The first one that the BIOS finds with a parallel 
port installed is assigned the logical name LPT1. The second, LPT2, 
etc. You can connect the PPIO to a port located at any of these 
three addresses. During power up the computer will assign that port 
a logical name but we will ignore it and communicate to the port 
directly. 
 
 

If you are using a base address of 0278H the I/O port addresses 

in Table 1 would change to 0278H, 0279H, and 027AH. With a base 
address of 03BCH the addresses are 03BCH, 03BDH, and 03BEH. 
Check your computer manual to find out which address your parallel 
port has. It is also possible to purchase a special parallel port from 
B&B Electronics that can be set at any address in the I/O port 
address space from 0000H to 03FFH. 
 
 

The above parallel port information is true for the vast majority of 

the PC compatible ports. However, a few computer manufacturers 
have chosen to make their parallel ports non-standard. On some 
battery powered computers pins are disabled to save power. Some 
ports may also have extra “direction control” bits. If you have 
problems where one or more bits are always on or off you should 
check your owner's manual. You may have to enable the port or set 
the “direction bit” correctly to get the port to work with the PPIO. If a 
pin is missing you may have to install a different parallel port card to 
get the PPIO to work properly.