21 Sep
2021
21 Sep
'21
10:38 a.m.
On Tuesday, September 21, 2021, 09:15:20 AM PDT, Paul Koning via cctalk <cctalk at
classiccmp.org> wrote:
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.
On Sep 21,
2021, at 12:00 PM, Jonathan Stone via cctalk <cctalk at 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.