3 Dec
2023
3 Dec
'23
7:19 p.m.
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… -
marketing info
--
John H. Reinhardt