DSD 4120 qbus floppy controller

Hi All, Digging through some more stuff. I found a DSD 4120 (NOT 4140) qbus floppy controller connected to two half-height 5 1/4 mitsubishi 4853-1112U flopppy drives. One of the floppy drives had a diskette that read: Scotch 3M 744-0 Diskette Single Head, Single side soft sector, single density A quick google didn't land any hits for the DSD 4120, but a few, including bitsavers had info on the 4140, They appear to be very similiar, but with a few differences. The 4140 is a RX02 controller. Is this another RX02 clone?? It's a 5 1/4 " not 8" and the floppy drive itself is capable of over 700MB. Could this be a RX50 clone?? Anybody senn one of these, any info?? Thanks Cheers Tom -- --- Please do not read this sig. If you have read this far, please unread back to the beginning.