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Version 3.00C
SCSI 2 Secure Digital Card
The Nimbus PC-186 came with the option of a SCSI controller and multiple Hard Drive configurations.

The standard equipment Hard Drives were:
Drive
Capacity
Tracks
Heads
Sec/Track
Blocks
Rodime RO652-20
20MB
306
4
34
41616
Seagate ST225N
20MB
615
4
17
41721
Seagate ST125N
20MB
407
4
26
41921
Miniscribe 8425S-30
20MB
41004
Conner CP3020
20MB
623
2
33
41118
Seagate ST225NP
20MB
615
4
17
41720
Conner CP3040
40MB
1026
2
40
82080


A fully populated card was required. If only half populated, its functionality was limited to just floppy drives.
RM IBM Mode Utility Board 

Other examples of the controller boards are as follows:
PN12865 RM Nimbus HDD SCSI Controller Card 2 PN12865 RM Nimbus HDD SCSI Controller Card RM Nimbus Floppy Controller Card 23731 PN12865 RM Nimbus HDD SCSI Controller Card external Connector RM Nimbus AX Board Winchester Controller RM Nimbus Floppy Controller Card 12865 Xebec SCSI SASI to MFM controller for RM Nimbus pc-186
SCSI 1 hard drives are now difficult to get hold of and fragile.

Technology now exists to impersonate a SCSI 1 Hard Drive via a controller and SD card:

Developed by an Australian guy called Michael McMaster http://www.codesrc.com

Here are some images of the controller fitted in a Slimline PC-186:

scsi2sd-rm-nimbus-top-view-3 scsi2sd-rm-nimbus-top-view-2 scsi2sd-rm-nimbus-front-2 scsi2sd-rm-nimbus-top-view scsi2sd-rm-nimbus-front scsi2sd-rm-nimbus-top-view-closeup

The Version 5 unit allows upto 4 devices.
Unfortunately the way in which the device adds drives, it does so on a 'per controller, 1st drive' basis
The Nimbus has it hard coded that the 2nd external drive must be on the 2nd drive of Controller 1.
This renders the 2nd external drive (E:) unusable, you do however get C: D: & F:



Using the maximum native sized drive available, the Conner CP3040 you get 40Mb per drive.

Booting from drive C: works perfectly


The process of establishing a new drive (real or SCSI2SD) is as follows:

I used a 2gb microsd from SanDisk, configured in the following way:

The Firmware used was 4.6 and the configuration file can be downloaded from here

Run 'config' and indicate how many internal & external winchesters the Nimbus has


The hard disk then needs to be prepared
There are limitations on the SCSI drives that can be used, refer to the list at the top of this page.
This is due to the proprietary way in which the drive is prepared, using the RM Software, HDFORM.


Select the appropriate controller and drive

...after a countdown timer of 5 minutes (presumably to give you time to abort should you think better of wiping the drive) the hard disk should then start formatting (not to be confused with a DOS format)

Next step is to run 'stamp', which prepares the partition.


After a reboot the drive is then required to be DOS formatted in the normal way (if its the boot drive, format c: /s).

A video of the process is as follows:

Information on SCSI to SD conversion
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