I also have multiple ESDI controllers, more than one these flavors: Dilog DQ686 http://www.bitsavers.org/pdf/dilog/2120-0137-1_DQ686_Nov89.pdf
Emulex QD21 http://www.bitsavers.org/pdf/emulex/QD2151002-J_QD21_Jun90.pdf Sigma SCD-RQD11-EC (There seems to be multiple versions from different vendors of this same basic board). http://www.bitsavers.org/pdf/sigmaInformationSystems/400740-B_SDC-RQD11-EC_Disk_Ctrl_Man_Jul88.pdf They all support block mode DMA transfers, and command queuing with seek optimization. The Dilog DQ686 and Emulex QD21 are dual wide boards. The Sigma SCD-RQD11-EC is a quad wide board and has 1MB of cache memory (which takes up about a quarter of the board area). The examples I have might only be populated with 512KB of cache memory. I might have had close to a dozen working full height 5.25-inch ESDI drives at one point. Unfortunately most of them have failed while sitting idle over the last few years. Without checking now I don't know if any of them still work. So the dozen or so Q-Bus ESDI controllers don't have any use for me now. (Fortunately I also have more Q-Bus SCSI controllers than backplanes to put them in). I also have a single Andromeda ESDC ESDI controller. Never found a manual for that one. Did eventually figure out how to get into the on-board configuration utility. On Tue, Apr 19, 2022 at 8:56 AM Douglas Taylor via cctech <email@example.com> wrote: > > Once upon a time I used an Emulex QD21, but I sold it because the actual > ESDI disks I had were a pain in the butt. Always crashing. > I still have a Webster (quad board) SRQD something. > I think I had a Dilog board also. It's been a while, probably 20 years. > Doug > > On 4/18/2022 9:12 PM, Chris Zach via cctech wrote: > > Interesting, what kind of ESDI controllers do you have? They got > > advanced features like cache, ordered seeks, and burst mode/block mode > > DMA?