So far, USB was only available for big Amigas with ZORRO (the Amiga's proprietary plug and play expansion slot system) or PCI slots and for the Amiga 1200's "clock port". The clock port is an internal port, only accessible after removing both the Amiga 1200's case and its metal shield. Primarily this port was only added by Commodore for internal model change purposes, e.g. selling Amiga 1200's with less memory etc, but it was never used. But as the clock port offers all necessary lines and is easy to implement it has recently seen some popularity to upgrade Amigas. Several clock port exansions have appeared, the Subway USB card, the Delfina sound card, fast serial ports etc. among them. And as more and more expansion cards for Amigas with ZORRO slots offer clock ports themselves for further expansion, the clock port has become a fairly attractive solution even for Amigas whose 5 or 6 ZORRO slots are already in use but need further expansion.

The Amiga 600 however does neither offer a ZORRO slot nor a A1200 compatible clock port. Therefore the expansion of this little Amiga with USB (or other clock port cards) seemed to be impossible.

For my upgrade plans however, I managed to get a prototype board that was never officially sold. This little board shown on the picture below expands the Amiga 600 with a Amiga 1200 compatible clock port and thus creates the necessary prerequisite to expand the Amiga 600 with all sorts of clock port expansion cards -- the Subway USB card (which was kindly given to me for testing purposes by KDH Datentechnik. Thanks!) being one of them.

However, there was a problem. Following our own advice we had thoroughly glued the Apollo onto the A600's mainboard. Of course, as we had to find out, the clockport expansion card was supposed to go underneath the Apollo onto the "Gayle" chip which with the Apollo glued into place seemed to be simply impossible. After all sorts of "How much can an Amiga 600 motherboard be bent without cracking" experiments that you really shouldn't repeat at home, the glue finally decided to let loose of the Apollo with a loud cracking nose. You can probably imagine the relief when we realized that it was NOT the A600's main board or the even the Apollo itself that had cracked... %-\

This shows a closeup of the prototype expansion board, expanding the Amiga 600 with a clock port (as always, click on the pictures for large versions):

This shows, how the clockport card sits between the A600's mainboard and the Apollo card.

And this shows the fairly small "Subway" USB card connected to the new clock port:

And this shows the Amiga 600 reassembled with the disk drive, the USB ports connected to the case and everything professionally held in place with duct tape ;-)

The following picture shows the GUI of the "Poseidon" USB stack which is already running fine with a special version of "subwayusb.device" (necessary because the A600's clock port resides at a different address space than the standard Amiga 1200's. Many thanks to Chris Hodges, developer of Poseidon, for that!). As you can see, the Poseidon stack has successfully found my USB optical mouse and has found and mounted my 128 MByte USB stick as an additional drive (click on picture for large version).

I have benchmarked the USB sticks speed with SysInfo. The average speed of the USB stick was 208023 bytes / sec which I think is a pretty good result for an old Amiga 600 with USB... B-)

This shows the back of the Amiga 600 with the USB ports nicely integrated with the case and my USB memory stick inserted. Cool, isn't it? B-)