
A   standard   X(E)1541  cable  won't work with _this_ driver. In
fact, there will probably never be a multitasking OS which  works
with one  of these. Anyway, the necessary modification is simple:


    Exchange pins 10 (ACK) & 11 (BUSY) on the parallel port.
    --------------------------------------------------------

The ACK line is the only line on a PC parallel port that can gen
erate a hardware interrupt. This way, we get  an  interrupt  when
the  device  releases the DATA line to signal "ready to receive".
Without an interrupt, you would have  to  poll  for  this  signal
about  every  100us,  which  is inacceptable for any multitasking
system.

Be sure to have your parallel port configured to use an IRQ, usu
ally 7 or 5, but both are often also used by soundcards.

(ASCII art taken from the StarCommander README :))


The PC parallel plug (male DB-25 connector):

        PaperEnd   Busy
    SelectIn   |   |   Ack        Data 7 - Data 0       Strobe
           |   |   |   |   +-------------+-------------+   |
           V   V   V   V   |                           |   V
        +------------------------------------------------------+
        | 13  12  11  10   9   8   7   6   5   4   3   2   1   |
        |  o   o   o   o   o   o   o   o   o   o   o   o   o   |
        +-+                                                  +-+
          |  o   o   o   o   o   o   o   o   o   o   o   o   |
          | 25  24  23  22  21  20  19  18  17  16  15  14   |
          +--------------------------------------------------+
             |                           |   ^   ^   ^   ^
             +-------------+-------------+   |   |   |   |
                        Ground          Select   |   |   AutoFeed
                                              Init   Error

The Commodore drive serial bus plug (male 6-pin DIN connector):

                                 Reset
                                   |
                                   V
                          +-------+ +-------+
                        +-+       +-+       +-+
                        |     5         1     |
               Data --> |     o    6    o     | <-- SrqIn
                        |          o          |
                        |     4         2     |
                Clk --> |     o    3    o     | <-- Gnd
                        |          o          |
                        +-+                 +-+
                          +-----------------+
                                   ^
                                   |
                                  Atn


This is the standard XE1541 cable (won't work with this driver):

    CBM drive serial port   PC parallel port

        2  Gnd ---------- 18-25  Ground
        3  Atn --------+---- 13  SelectIn
                       +->|-- 1  Strobe
        4  Clk --------+---- 12  PaperEnd
                       +->|- 14  AutoFeed
        5  Data -------+---- 11  Busy
                       +->|- 17  SelectIn
        6  Reset ------+---- 10  Ack
                       +->|- 16  Init


This is the modified one (pin 10 & 11 on the p.p. exchanged):

    CBM drive serial port   PC parallel port

        2  Gnd ---------- 18-25  Ground
        3  Atn --------+---- 13  SelectIn
                       +->|-- 1  Strobe
        4  Clk --------+---- 12  PaperEnd
                       +->|- 14  AutoFeed
        5  Data -------+---- 10  Ack          <-+
                       +->|- 17  SelectIn       |
        6  Reset ------+---- 11  Busy         <-+
                       +->|- 16  Init

