This may explain your problem.
http://en.wikipedia.org/wiki/Micro_Channel_Architecture
It was a replacement slot design made by IBM to remove
limitations in the older ISA slot type.

They were not too popular and did not go too "main stream".
26 years later I still have fairly new machines (2002?) that
still used the ISA bus instead... (At most, one slot.)

I saw limited numbers of them, generally in a commercial
or business setting. Being IBM, everything was pretty
expensive.
                                      Rick Glazier


----- Original Message ----- 
From: "Greg Purvis"
> I've an AMBRA 486 Computer that I want to use to connect to a small 
> network shared with two other PCs.
> 
> I haven't found out much about 'Ambra' yet, but it seems to be a 
> hardware-software combination created by IBM, dating over to the early 
> 90's. 
> 
> I tried to insert a card for an ethernet cable, but the slots are 
> different, the card won't fit.
> 
> Did IBM, or some other company, build specially-shaped cards to plug 
> into these machines, and was an ethernet card/socket one of them?

               The NOSPIN Group Promotions is now offering
                 our special coffee mugs and mouse pads
              with the PCBUILD logo...  at a great price!!!
             http://freepctech.com/goodies/promotions.shtml