[Coco] Can't copy real floppy to CoCo-SDC on a CoCo 2

[Richard E Crislip]

On Fri, 27 Feb 2015 14:15:06 -0500 (EST)
mike at borncoco.com wrote:

> This issue is a floppy drive issue as I've removed the CoCo-SDC and
> replicated the same issue with real floppies. I changed disk
> controllers just to eliminate that as an issue. I reinstalled drive
> 1. It has no terminator and the DS jumper is set to D1. Same
> symptoms. I can read & write to each drive individually without
> issue, but the "BACKUP" command between the two drives (D0 & D1)
> fails with an "?IO ERROR". Ideas?

It may be the cable. Are you using a straight through cable or one with
a twist in it?