On Tuesday, September 21, 2021, 09:15:20 AM PDT, Paul Koning via cctalk <cctalk@classiccmp.org> wrote: >> On Sep 21, 2021, at 12:00 PM, Jonathan Stone via cctalk >> <cctalk@classiccmp.org> wrote: >> >> The RD53s in both Microvax 2000s are dead. I'm reluctant to buy more 30+ >> year old rotating media. >> If I'm going to buy a disk emulator, I'd much prefer SCSI to MFM, for the >> obvious performance reasons. > > >Emulators presumably act, performance wise, like SSDs. Given that, an MFM >emulator will significantly outperform a SCSI hard >drive since it has no seek >delays. > >David Gesswein's MFM emulator works impressively well and is inexpensive, too.
My comparison was MFM emulators versus SCSI emulators. scs2sd is significantly cheaper than David Gesswein's MFM emulator; and higher performance. (IIRC, Gesswein's emulator transfers entire track images between SSD and RAM, but I may be remembering DREM documentation instead.). OTOH, for a machine which already has an MFM controller but no SCSI, an MFM emulator is cheaper than scs2sd plus SCSI controller. (At least for Qbus. At eBay prices, even RQDX3 plus distribution panel plus emulator, is cheaper than bootable SCSI controller plus SCSI emulator). SCSI performance will still be better.
