Discussion:
On target with the IBM SCSI2SD!
(too old to reply)
Louis Ohland
2017-03-19 02:51:13 UTC
Permalink
Studd Gunn Productions brings you another innovation from a MAD scientist.

http://ps-2.kev009.com/ohlandl/IBM_SCSI/IBM_SCSI2SD.html

The design is compatible with Tribble, Spock, Corvette, and Enhanced
Turbo Corvette 50 pin edgecards.

All IBM SCSI controllers (non-RAID) have the 50 pin edgecard at the same
location. Ever swap a Spock with a Corvette? The socket for the edgecard
is >right there<.

I assume the 44/45 pair will support this. Earlier SCSI BIOS might be
limited to 1GB. Don't know if you can IML off this.

Oddly enough, the SCSI2SD can emulate a floppy drive.... Wonder what
size and how the heck to format that SD card... Though I have seen
floppy emulators that had like 70 floppy images on them to work with a
system expecting a floppy of 1.44MB
Louis Ohland
2017-03-19 02:56:23 UTC
Permalink
Some belated thoughts.

To remove an SD card while the system is up should be done with the SCSI
"EJECT" command, I bet.
David Wade
2017-03-19 10:29:03 UTC
Permalink
Post by Louis Ohland
Studd Gunn Productions brings you another innovation from a MAD scientist.
http://ps-2.kev009.com/ohlandl/IBM_SCSI/IBM_SCSI2SD.html
The design is compatible with Tribble, Spock, Corvette, and Enhanced
Turbo Corvette 50 pin edgecards.
All IBM SCSI controllers (non-RAID) have the 50 pin edgecard at the same
location. Ever swap a Spock with a Corvette? The socket for the edgecard
is >right there<.
I assume the 44/45 pair will support this. Earlier SCSI BIOS might be
limited to 1GB. Don't know if you can IML off this.
Oddly enough, the SCSI2SD can emulate a floppy drive.... Wonder what
size and how the heck to format that SD card... Though I have seen
floppy emulators that had like 70 floppy images on them to work with a
system expecting a floppy of 1.44MB
How does this compare with the RAID in in the P390 servers? I was
thinking of using one in my PC/Server but was a bit worried it would be
slow...

Dave
Kevin Bowling
2017-03-19 11:41:25 UTC
Permalink
Post by David Wade
Post by Louis Ohland
Studd Gunn Productions brings you another innovation from a MAD scientist.
http://ps-2.kev009.com/ohlandl/IBM_SCSI/IBM_SCSI2SD.html
The design is compatible with Tribble, Spock, Corvette, and Enhanced
Turbo Corvette 50 pin edgecards.
All IBM SCSI controllers (non-RAID) have the 50 pin edgecard at the same
location. Ever swap a Spock with a Corvette? The socket for the edgecard
is >right there<.
I assume the 44/45 pair will support this. Earlier SCSI BIOS might be
limited to 1GB. Don't know if you can IML off this.
Oddly enough, the SCSI2SD can emulate a floppy drive.... Wonder what
size and how the heck to format that SD card... Though I have seen
floppy emulators that had like 70 floppy images on them to work with a
system expecting a floppy of 1.44MB
How does this compare with the RAID in in the P390 servers? I was
thinking of using one in my PC/Server but was a bit worried it would be
slow...
Dave
The issue with these gadgets so far is that they are narrow SCSI so they
will bring a wide SCSI bus speed down to that. On the other hand you
eliminate head seek time. The flash and conceivable
FPGA/microcontrollers doing the glue should be able to saturate any
equipment from this era, so it'd be cool to see an ultrawide version
perhaps with CompactFlash.

I guess if you can spare enough MCA slots, if you software RAID-0 a few
Corvette+SCSI2SD pairings together (if your OS supports striping) you
might be able to hotrod a box past era performance.

Regards,
Kevin
Louis Ohland
2017-03-19 12:49:57 UTC
Permalink
Already we have feature creep and the product has not even hit the streets.

The v6 SCSI2SD is Fast/Narrow. A good match for the Corvette interior
edgecard.

The v5 and earlier should be a good replacement for DBA-ESDI with the
short Tribble. Some diddling will helping in using the Patriot, which is
a close match to the v5 SCSI2SD.

In the future? Weeellll... The idea of a stack of microdisks in a frame,
ready to be slid into a P75 would make it a Portable Server... Issue
would be the planar Tribble. RAID in software.

Interesting challenge of hooking up all those IDE interface drives.

As to the CF solid state on a RAID controller... Same edgecard
configuration (much smaller!). I don't have any alcohol to fuel cogitation.

If you really want to burst out of realspace, what about using a Cheetah
sidecard with a Corvette, and mount a SCSI2SD on that? These folks have
already fabbed an external HPDB50 enclosure with a 3D printer, Shirley
one could do the same with HPDB68...

Need coffee.
Post by Kevin Bowling
The issue with these gadgets so far is that they are narrow SCSI so they
will bring a wide SCSI bus speed down to that. On the other hand you
eliminate head seek time. The flash and conceivable
FPGA/microcontrollers doing the glue should be able to saturate any
equipment from this era, so it'd be cool to see an ultrawide version
perhaps with CompactFlash.
I guess if you can spare enough MCA slots, if you software RAID-0 a few
Corvette+SCSI2SD pairings together (if your OS supports striping) you
might be able to hotrod a box past era performance.
Regards,
Kevin
WBSTClarke
2017-03-19 13:22:12 UTC
Permalink
Post by Louis Ohland
Already we have feature creep and the product has not even hit the streets.
The v6 SCSI2SD is Fast/Narrow. A good match for the Corvette interior
edgecard.
The v5 and earlier should be a good replacement for DBA-ESDI with the
short Tribble. Some diddling will helping in using the Patriot, which is
a close match to the v5 SCSI2SD.
In the future? Weeellll... The idea of a stack of microdisks in a frame,
ready to be slid into a P75 would make it a Portable Server... Issue
would be the planar Tribble. RAID in software.
Different OSes have implemented "Fault Tolerant" (pseudo RAID-1?) drive support.
Post by Louis Ohland
Interesting challenge of hooking up all those IDE interface drives.
There already exist SCSI to IDE drive interface adapters, I have these (admittedly expensive) adapters in my Pioneer DRM-6NX CD-ROM servers.

I also have an ALogic SCSI to SATA interface adapter for a SATA DVD writer.
Post by Louis Ohland
As to the CF solid state on a RAID controller... Same edgecard
configuration (much smaller!). I don't have any alcohol to fuel cogitation.
If you really want to burst out of realspace, what about using a Cheetah
sidecard with a Corvette, and mount a SCSI2SD on that? These folks have
already fabbed an external HPDB50 enclosure with a 3D printer, Shirley
one could do the same with HPDB68...
Don't forget, it's not the connector but the control and data path logic needed to support SCSI Wide transfers. Negotiation of Wide support (not present in the IBM adapters' firmware) would be all that is required to allow Narrow and Wide DASD devices to co-exist on the same bus. Narrow tape and CD-ROMs are not a problem, being of a different class of SCSI device.
Post by Louis Ohland
Need coffee.
Likewise.
Post by Louis Ohland
Post by Kevin Bowling
The issue with these gadgets so far is that they are narrow SCSI so they
will bring a wide SCSI bus speed down to that. On the other hand you
eliminate head seek time. The flash and conceivable
FPGA/microcontrollers doing the glue should be able to saturate any
equipment from this era, so it'd be cool to see an ultrawide version
perhaps with CompactFlash.
I guess if you can spare enough MCA slots, if you software RAID-0 a few
Corvette+SCSI2SD pairings together (if your OS supports striping) you
might be able to hotrod a box past era performance.
Regards,
Kevin
Lorenzo Mollicone
2017-03-20 02:48:05 UTC
Permalink
Each SCSI2SD adapter can emulate four SCSI devices. You could create an entire array in one slot.

Of course I can't find the SD cards to save my life, so the madness will continue tomorrow !
David Wade
2017-03-20 10:24:35 UTC
Permalink
Post by Lorenzo Mollicone
Each SCSI2SD adapter can emulate four SCSI devices. You could create an entire array in one slot.
Of course I can't find the SD cards to save my life, so the madness will continue tomorrow !
but it wouldn't buy you anything...

Dave
WBSTClarke
2017-03-20 12:04:53 UTC
Permalink
Post by Lorenzo Mollicone
Each SCSI2SD adapter can emulate four SCSI devices. You could create an entire array in one slot.
Of course I can't find the SD cards to save my life, so the madness will continue tomorrow !
There are microSD to SD card adapters and SD cards here:

https://www.mymemory.co.uk/SD-Cards

but that's just a UK site. There must be many sites in the US too.
David Wade
2017-03-20 12:48:56 UTC
Permalink
Post by WBSTClarke
Post by Lorenzo Mollicone
Each SCSI2SD adapter can emulate four SCSI devices. You could create an entire array in one slot.
Of course I can't find the SD cards to save my life, so the madness will continue tomorrow !
https://www.mymemory.co.uk/SD-Cards
but that's just a UK site. There must be many sites in the US too.
My local Sainsbury's and Tesco both have a wide range of quality branded
SD Cards..
Lorenzo Mollicone
2017-03-20 13:30:28 UTC
Permalink
no, I have SD cards !

I just put them someplace "safe"...

"So they wouldn't get lost..."

And here we are... and they're missing in action... LOL
WBSTClarke
2017-03-20 13:57:25 UTC
Permalink
Post by Lorenzo Mollicone
no, I have SD cards !
I just put them someplace "safe"...
"So they wouldn't get lost..."
And here we are... and they're missing in action... LOL
Oh, can't find *your* SD cards. I know that kind of feeling... (I know I put them around here somewhere!) :-D
WBSTClarke
2017-03-19 12:40:26 UTC
Permalink
Post by Louis Ohland
Studd Gunn Productions brings you another innovation from a MAD scientist.
http://ps-2.kev009.com/ohlandl/IBM_SCSI/IBM_SCSI2SD.html
The design is compatible with Tribble, Spock, Corvette, and Enhanced
Turbo Corvette 50 pin edgecards.
All IBM SCSI controllers (non-RAID) have the 50 pin edgecard at the same
location. Ever swap a Spock with a Corvette? The socket for the edgecard
is >right there<.
I assume the 44/45 pair will support this. Earlier SCSI BIOS might be
limited to 1GB. Don't know if you can IML off this.
Oddly enough, the SCSI2SD can emulate a floppy drive.... Wonder what
size and how the heck to format that SD card... Though I have seen
floppy emulators that had like 70 floppy images on them to work with a
system expecting a floppy of 1.44MB
FWIW, the Patriot/MCS600/MCS700 could be accomodated fairly simply with a 50-pin IDC female on a slightly longer ribbon cable. I did something similar with floppy drive card-edge and pin connectors on a ribbon cable.

The later OS/2 FixPaks, with the "Removable Media Support" supposedly treated the SCSI Zip, Jaz and Sysquest drives as big floppies. Generally speaking those were pre-formatted, so I'm unsure about that aspect for SD cards.

Cheers,
WBST
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