MIO with cartridge ports?

My MIO doesn't have any, but http://www.atarimuseum.com/faqs/HARD_FAQ.HTML#ddmio says that it should:

 

MIO

ICD manufactured this wonderboard in 1987. Connected to the PBI or ECI, it provided either 256k or 1Meg of RAM, an RS232 port, a parallel printer port and a SCSI hard drive port. The RAM can be configured as a RAMdisk or printer buffer, or via software as a hard disk cache. To connect it to a 130XE ECI required a special adapter that would convert the 130xe's cartridge/ECI to an 800XL compatible PBI. The little board had two cartridge slots (the rear of the two works for some cartrige types only, like Rtime This looked better than having a tower of stackable cartriges coming out of your 800XL! (Spartados X, Rtime8, and Action all plugged on top of each other is rather obtrusive on an 800XL  

Am I confused on what they are talking about?