Tài liệu Parallel Port Complete- P2 doc
Tài liệu Parallel Port Complete- P2 doc
... clues.
1
0
Parallel Port Complete
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Table 2-2: Parallel port bits, arranged by register.
Accessing Ports
Parallel Port Complete
1
9
Data ... current, and if your parallel port has weak outputs, you may have
problems in using other devices on the same port as the key.
Alternatives to the Parallel...
Tài liệu Parallel Port Complete- P1 doc
... (SPP)
The parallel port in the original IBM PC, and any port that emulates the original
port& apos;s design, is sometimes called the SPP, for standard parallel port, even though
the original
port
had ... early PCs, the parallel port had a base address of 3BCh. On newer systems, the
parallel port is most often at 378h. But all three addresses are reserved for parallel
por...
Tài liệu Parallel Port Complete- P4 doc
... other waveform by connecting a parallel port& apos;s
outputs to the inputs of a digital-to-analog converter (DAC, and writing a repeat-
ing series of bytes to the port. One way to generate the ... remove this watermark.
Programming Issues
Ports that support ECP mode can use direct memory access (DMA), where data
can transfer between memory and a port without intervention by the CPU. The...
Tài liệu Parallel Port Complete- P3 pdf
... 0;
Pascal programmers can use the port function to access parallel ports.
To write
AAh
to a Data port at 378h:
port[ 378h]:=AAh
To read a Status port at 379h:
value: =port[ 379h]
Delphi 2.0
The 32-bit ... ability.
EPP and ECP Support
A port that supports EPP or ECP modes of data transfer has the best chance for
fast parallel- port transfers. An SPP requires four port writes to...
