Programming documentation for the X-Surf ethernet board

This document is freely distributable as long as it is not changed, and one
of the sources www.jschoenfeld.com, www.jschonfeld.com, www.siliconsonic.com
is mentioned.

Last updated: June 28th, 2000

Vendor ID: 4626 ($1212)
Product ID: 23 ($17)
Serial ID: 0
          Other IDs are reserved for future use, if you write your drivers
          for any of the expansion ports, check this document regularly.
          Some options of the board may be removed in order to save money.
          This will be represented in the serial ID.

The autoconfiguration of the X-Surf is completely implemented as Commodore
has defined. All the features are available, including shutup_forever and
storage of the whole address word, meaning, the card can be mapped anywhere
in the 24-bit memory space. Even computers with bad or missing clock-signals
are supporded.


Memory map:

$0000-$007c     Config-Nibbles.
                in config nibbles:
                $0040 Bit 7 and bit 5 represent the status of the
                Ethernet IRQ. Bit 5 and Bit 7 are always identical, it's
                implemented this way because Commodore has specified these
                bits as IRQ bits. See autoconfig docs for further info.
$007e           bit 7 represents the status of the IDE IRQ line. Both
                IDE ports use the same IRQ, so you shouldn't start more than
                one IOrequest at a time.
                Writing to this register controls the A11 line of the local
                ISA bus. This is necessary because of the limited address
                space on the Amiga side (only 4K for the ISA). A11 adds $800
                to the address of the ethernet card, allowing you to reach
                the Plug'n'play registers. Writing $80 adds $800 to the
                address, while writing $00 gives you the normal IO address 
                space of the ethernet board.
                !!Be careful: Reading this register may also affect the A11
                line, so after a read, the A11 status must be restored!!
                Since the normal status of the A11 line is 0, writing 0 to
                this register after the status read is recommended. For
                further security, you should disable all IRQs during the
                Plug'n'play isolation phase. If you want to make it
                Amiga-like, only disable the IRQs while the A11 line must
                be high.
$0080-$7fff     mirrors of the above. Do not access, it's reserved for future
                use, don't rely on these mirrors!
$8000-$8fff     ISA bus IO addresses. All addresses are "times two", so if
                you want to access 0x300, the address is located at $8600 on
                the Amiga side. All read-accesses allowed (even and odd
                bytes, words, long-words), writing should only be done with
                word-accesses.
$9000-$9ffe     26-pin expansion port. This port is 8-bit wide, and it uses
                even addresses. 
$a001-$afff     clock-port 1. The clock-port is 8-bit wide, this one uses
                odd addresses. Spare_CS only. Address lines used are the same
                as in the Amiga 1200.
$b000-$bfff     2,5 inch IDE port. Lower CS only (IDE-fix style).
                Alternate status register and reset register are not
                available with this style of controller.
$c000-$cffe     clock-port 0. The clock-port is 8-bit wide, this one uses
                even addresses. Spare_CS only. Address lines used are the
                same as in the Amiga 1200. 
$d000-$dfff     3,5 inch IDE port. Lower CS only (IDE-fix style).
                Alternate status register and reset register are not
                available with this style of controller.
$e000-$efff     ISA bus memory mapped area. Since only the memory area from
                0x0000 to 0x0800 can be accessed, this address space can be
                considered as "nirwana" - writing will not access anything,
                and reading will give random data. Totally useless.
$f000-$ffff     Unused. 

If you have any questions, feel free to ask via e-mail:
jens@siliconsonic.de