On 12/3/2023 10:27 AM, Douglas Taylor via cctalk wrote:
That is my question.
I have used a couple of versions of the SCSI2SD boards in the past with Viking,
Emulex QC07, DEC RQXZ1 controllers in the past, and also direct connections to
MicroVax SCSI buss's.
There are other manufacturers of these SD to SCSI emulators now. What is the
current SOA? What works, what doesn't work with DEC hardware?
Doug
State of the Art SCSI replacement is the ZuluSCSI RP2040 which is from the same
people as SCSI2HD (I think - at least the same US Store). In any case the
SCSI2HD is generally out of stock unless there is some NOS left. The ZuluSCSI
is what is in production now.
It's under continual development with fixes and new features are being added
(for better or worse). I have two in a MicroVAX3100-95. One is the main file
systems - I have a 256GB SD card where there are 4 drives allocated. There are
two 50GB main drives and 2 9GB system drives. I have them mirrored under VMS
Volume Shadowing. I aim to use about 50% of the capacity of the SD card to
allow plenty of space for the card's firmware to do wear leveling. They are
SAMSUNG PRO Endurance cards with an estimated endurance of 140k hours. The
other ZuluSCSI RP2040 card is mounted for external access and is the backup
device. This gets rotated regularly.
All that said, in the MV3100 they are still slower by a touch than rotating
disks. But after having several Ebay SCSI disks have controller issues
(shorting and burnt out controllers) I am hoping these are more trouble free.
I also have 2 older SCSI2HD in my AlphaServer DS10 systems for removable
storage. When I get a chance I am swapping them out for the ZuluSCSI RP2040
models because they are slightly faster and much easier to manage.
The ZuluSCSI is a hybrid of the SCSI2HD hardware and SCSI firmware and the
BlueSCSI management firmware. With the SCSI2HD you needed a utility (mostly)
to mange the settings of the SCSI2HD card. COpying the data to the card
usually meant using a utility like dd or something that could write to specific
places on the card. With the ZuluSCI you format the SD card in FAT or EX-FAT
(if your disks are bigger than 4GB) and put them on the card with a specific
name format. The documentation explains it all pretty clearly.
www.zuluscsi.com - US Store and some documentation
https://github.com/ZuluSCSI/ZuluSCSI-firmware/wiki/ZuluSCSI-Manual -
Documentation
https://github.com/ZuluSCSI/ZuluSCSI-firmware - firmware
https://www.amazon.com/gp/product/B09WB3D5GQ - Samsung PRO Endurance
https://semiconductor.samsung.com/consumer-storage/memory-card/micro-sd-pro-endurance/
- marketing info
--
John H. Reinhardt
