WTB: ISA riser for a IBM PS/1 2011 or 2121 model

[nestor]

I'm looking for a ISA riser card for a IBM PS/1 model 2011 or 2121. Most 2121 came with it, but it was part of an upgrade in the 2011 model.

 

[Stone]

I have two standard 16-bit ISA riser cards. One has 5 16-bit slots on it -- 3 on one side and 2 on the other. The other card has 3 16-bit slots on one side and 2 8-bit slots on the other. If you want pics, lemme know.

 

[nestor]

Standard ISA risers will not work in these machines.
The edge conector to the motherboard looks like a PCI connector:
http://i208.photobucket.com/albums/bb147/fjk61011/PSslash1/DSC00605.jpg (photo by fjk61011)

 

[Stone]

Nestor, that is *not* ISA*. It looks more like microchannel.

 

[nestor]

Perhaps IBM reused MCA-type slots where the riser is connected to the motherboard, but only for the connection. Inside signals are ISA for sure. In the picture you can see only the bottom connector, in the upper part there are standard ISA slots.

 

[Stone]

Perhaps IBM reused MCA-type slots where the riser is connected to the motherboard, but only for the connection. Inside signals are ISA for sure. In the picture you can see only the bottom connector, in the upper part there are standard ISA slots.

If that's the case why won't standard ISA risers work?

 

[nestor]

Because a standard ISA will not fit into a MCA shape slot...

 

[invoke]

nestor Is that the photo of an actual 2011 riser card? Do you have any other photos? I'm trying to find the schematics of what the ACU looked like or contained.

 

[luizapper]

The riser photo that was posted before by @nestor is for the 2011 model (physically similar to a MCA 16-bit connector).
The 2121 riser card has a connector that is physically identical to "MCA 16-bit with AVE" connector (MCA Pinouts)