BlueSCSI - Open, Low Cost, DIY SCSI to SD device

[YMK]

I noticed on an image posted by a BlueSCSI user that the resistor nets aren't socketed and the assembly instructions confirm this.

It looks like the nets sit directly on the data lines. Is this correct?

 

[eric]

It looks like the nets sit directly on the data lines. Is this correct?

Yep, you can also download the KiCad project if you'd like to see how it's all connected.

 

[YMK]

Thanks for confirming. There's a problem with permanently installed nets...

Disconnecting the commons from VCC and ground does not remove the other pins from the circuit.

The lines are still connected to each other in a star arrangement.

I don't have a BlueSCSI to measure, but I'm betting you'll read somewhere around 264 Ohms between lines on the same net.

 

[eric]

Yes, it's a bit of a trade off for usability and in practice I've not seen this be an issue - and having the user remove & loose resistors or install them backwards or in the wrong position would be quite complex.

 

[YMK]

Yes, it's a bit of a trade off for usability and in practice I've not seen this be an issue - and having the user remove & loose resistors or install them backwards or in the wrong position would be quite complex.

Aren't many BlueSCSIs user-assembled? Seems they have to get it right at least once.

Passing current between data lines might not be an issue for a single BlueSCSI.

If you have two, that resistance drops to 132 Ohms. Three? 88 Ohms.

For that reason, on most devices, nets are either socketed or electrically disconnected from the circuit when termination is disabled.

 

[eric]

Aren't many BlueSCSIs user-assembled?

many are, many are not.

Three unterminated BlueSCSI's seems like an unlikely setup, but I suppose someone could set it up that way.

Just as an FYI this is the same termination setup RaSCSI uses as well.

Maybe it could be improved? Any pull requests or design improvements are welcome.

 

[YMK]

Just as an FYI this is the same termination setup RaSCSI uses as well.

Maybe it could be improved? Any pull requests or design improvements are welcome.

I did not know that about RaSCSI. I haven't looked at its design.

SIP sockets would be all that's needed.

 

[retr01]

SIP sockets would be all that's needed.

So, SIP as in Session Initiation Protocol, or is that something else?

 

[YMK]

So, SIP as in Session Initiation Protocol, or is that something else?

Single inline pin. It's a physical part. I don't think any DIP sockets will match the spacing on the current PCB.

 

[retr01]

Single inline pin. It's a physical part. I don't think any DIP sockets will match the spacing on the current PCB.

Duh me. Gotcha! Thank you, @YMK.

 

[wottle]

Anyone used a BlueSCSI in the tray mounted Macs (LC575 / Mac TV / etc) that use an edge connector? Thinking you'd need to pair one of the desktop versions of BlueSCSI by @Androda with a 3d printed mounting bracket that would align the SCSI connector at the right spot so you could plug the edge connector from the original drive into the BlueSCSI.

Only other option I can think of would be some type of SCSI extension cable plugged into the edge connector and then into a standard BlueSCSI. Really would love to have the internal mounted drive for my Mac TV. Thanks for any ideas y'all might have.

 

[Fizzbinn]

This is what I use in my 575.

CablesOnline 6 inch Internal IDC 50-Pin SCSI Male/Female Extension Ribbon Cable | eBay

CablesOnline Part Number: FR-5006M. Connectors: 2.54-Pitch 1x IDC 50-Pin Male, 1x IDC 50-Pin Female. This cable will extend the length of your IDC-50Pin SCSI Cable. IDC 50-Pin can be used for internal SCSI-1 / SCSI-2 applications, such as hard drives, cd-roms, removable storage drives, etc.

www.ebay.com

…it’s a bit fiddly to get everything plugged in, I used some tongs to get the edge connector + extension cable plugged in, but works!

 

[wottle]

I ended up buying the extra long version of the extender (23 inch extender). I'll try doing the same with some tongs / tweezers to get it connected.

May order a desktop f4 and see if I can make a 3d printable mounting bracket for it. We'll see.

 

[retr01]

I think I'll need a longer SCSI cable in my SE/30 for my @Androda F4 Lite BlueSCSI. Perhaps the flexible cable from @Kay K.M.Mods would be best.

 

[Androda]

I'm hoping to have time soon to do all the calculating and get things in the right place for LC 520 and similar. With the SCSI port facing the right direction on my products, it should be easier. And I have yet another revision of the connector end that should make it even easier to line things up.

 

[eric]

Optical Beta ​

Release Optical Beta · erichelgeson/BlueSCSI

This is a beta release of optical support for BlueSCSI based on #130 by @mynameistroy You can now create SCSI optical drives with .iso, .bin, .toast, and other raw optical formats. BlueSCSI will tr...

github.com

This is a beta release of optical support for BlueSCSI based on #130 by @mynameistroy

You can now create SCSI optical drives with .iso, .bin, .toast, and other raw optical formats.

BlueSCSI will try to determine the correct block size for optical, but you may need to specify it in certain situations.

Reporting Success, Issues, and Questions in beta​

If you have Success, Issues, and Questions please use the discussion.

If you have technical feedback please report that in the Pull Request.

Usage:​

Follows the same naming conventions as Hard Disks, except using CD
CD30_2048-MacOS8.6.iso - SCSI ID 3, LUN 0, 2048 sector size.
Remember file names must be less than 32 characters.

Bootable Images​

Some images created do not have the proper bits to be detected as bootable on a Mac. We are compiling of known good images here https://github.com/erichelgeson/BlueSCSI/wiki/CD-Image-Support

Known behaviors​

Eject currently does nothing, we have some interesting plans around CD switching in the works.
If an image file has the read only attribute checked it is currently skipped (some CD images have this checked) - will be fixed in next beta.

Flashing​

USB Boot loader​

If you have the USB Boot loader you can flash any of the -USB firmware to your devices using this branch of the BlueSCSI-Updater or QMK Toolbox (generic DFU util for windows/mac)

ST-Link​

If you do not have a USB bootloader you can flash via ST-Link v2.

Gratuitous 7 CD images mounted at the same time:

 

[retr01]

@eric, is a video available illustrating the steps to flash the firmware on the BlueSCSI? I am a bit wary after my Floppy Emu got bricked. I have @Androda's BlueSCSI F4 Lite

 

[Andrew737953]

Hello,
I now have a fully assembled BlueSCSI and I’m not able to get it working. It worked fine for a while except that it didn’t boot up, but now it won’t turn on at all. It’s not my Macintosh I don’t think because my bad BlueSCSI I built myself still powers up and blinks. Any ideas on how to get it back on?

 

[eric]

I now have a fully assembled BlueSCSI and I’m not able to get it working. It worked fine for a while except that it didn’t boot up, but now it won’t turn on at all.

Can you disconnect it from the computer and power it via the MicroUSB on the BluePill? Is it possible you shorted it out while powering it? eg having it touch something metal while it was powered on.

Also you may want to start your own thread for troubleshooting. Please include as many details as you can about what mac you have, what you've tried, etc.

 

[Andrew737953]

It didn’t work over MicroUSB. What do I do if it’s shorted.