Epson Stylus Color 660 Manual page 58

Note:
If your printer is connected to LPT1, only the LPT1 tab is available.
Resources Settings (IRQ and DMA)
If you have connected your printer to LPT2 or LPT3, making IRQ
and DMA settings here may speed up printing. Input the same
configuration numbers for IRQ and DMA which you have made
with your expansion board. See your computer documentation to
determine the settings for IRQ and DMA.
Use DMA transfer
Using DMA transfer to send print data to the computer may help
you speed up printing. If the Use DMA Transfer check box is
dimmed, you must first enable DMA transfer in your computer
settings. For details, see your computer documentation.
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