BlueSCSI Issues - Bus Error

[rjkucia]

This is a continuation of an old thread: https://tinkerdifferent.com/threads/macintosh-se-wont-boot-system-7.792/

tl;dr - Booting System 7 off of my BlueSCSI didn't work. I got a RaSCSI instead, and that worked.

Since then I put the BlueSCSI away and didn't think about it too much. I've upgraded to an SE/30 board in my SE, and have been pretty happy with the RaSCSI. I wanted to try out the BlueSCSI again and see if I was still having the same issues. Using an image containing 7.5.3 that is confirmed to work when booting from my RaSCSI, I got a "bus error" bomb during boot. I've tried multiple SD cards with similar results.

Since the common denominator at this point is the BlueSCSI itself, what would you all recommend for starting to troubleshoot?

 

[rollmastr]

Has the BlueSCSI ever worked? Who assembled it? Do you have a picture of the PCB?

 

[eric]

The Troubleshooting guide is the best place to start - has almost everything we've come across. Don't skip any steps even if you think you've tried it before.

Troubleshooting

A small SCSI device based on stm32. Contribute to erichelgeson/BlueSCSI development by creating an account on GitHub.

github.com

 

[JDW]

@rjkucia
I quickly skimmed through the older thread you linked for us, and the resounding theme I spotted was LIDO.

I suggest trying another formatter to see if that helps, such as the patched Apple HD Setup 7.3.5. Not sure if Disk Jockey will be a help to you, but you should check that out.

The 3 questions by @rollmastr are also important to answer.

Lastly, is BlueSCSI the only device in the SCSI chain? I ask because SCSI Termination Voodoo could be at work.

 

[rjkucia]

Has the BlueSCSI ever worked? Who assembled it? Do you have a picture of the PCB?

It did work with System 6 on my SE; however there were still some weird issues that popped up occasionally, so I think the extra overhead of loading System 7 is what triggered it. @Drake assembled it. I can get a picture of it later today.

I suggest trying another formatter to see if that helps, such as the patched Apple HD Setup 7.3.5. Not sure if Disk Jockey will be a help to you, but you should check that out.

Should this be an issue even if the images work fine with a RaSCSI? I did try a new Disk Jockey image with System 7 on it, but no dice. I forget if it was the same error or a different one - I can try that again and double check.

Lastly, is BlueSCSI the only device in the SCSI chain? I ask because SCSI Termination Voodoo could be at work.

It's the only SCSI device installed, and the termination jumper is set. I've tried both on the internal bus and on the external bus with an OverEasy.

The Troubleshooting guide is the best place to start - has almost everything we've come across. Don't skip any steps even if you think you've tried it before.

Troubleshooting

A small SCSI device based on stm32. Contribute to erichelgeson/BlueSCSI development by creating an account on GitHub.

github.com

Thanks - I went through those originally, but I can do them again.

 

[pfuentes69]

Could it be a bad solder joint?
I had this is issue in a couple of units I made myself. Apparently after plugging/unplugging several times it stopped working and desoldering the 50-p connector worked again. I also had issues with the soldering of the SD-Card socket.

 

[JDW]

There is an easy solution, but it will take time, cost money, and you would need to cooperate with @Drake to do it -- send it to Drake so he can perform his own testing, and if he finds issues on some of his own Macs which are different from yours and which he knows that BlueSCSI works fine with, then there could be a dry solder contact somewhere which needs to be resoldered to fix the problem. You have done a fabulous amount of testing which shows that something very well could be wrong on the PCB itself.

 

[rjkucia]

Here are some pictures of it - let me know if I should look at something further!

 

[JDW]

I cannot see anything bad from those photos. I would assume that @Drake tested it since he build it, but to what extent he tested it prior to shipping to you should be discussed with him. Clearly, you are having some serious problems and you have also done some serious testing to determine what that problem is, yet you've come up with nothing. So that leads us back to the hardware.

Now, I've heard about fake and genuine chips being used on BlueSCSI devices, but I had the understanding it would function fine with either. @eric knows more about that than I do though, so perhaps he can share some thoughts. But for now, it doesn't appear that you are doing anything wrong.

 

[Drake]

Here are some pictures of it - let me know if I should look at something further!

This is from the first set of PCBs I ever did!
literally a collectors item (kidding).

I do recall there being a termination issue with the early revision of bluescsi and there should be photos pertaining to the bodge required on the wiki!
let's check:

BlueSCSI/docs/1.0b-to-1.0c.adoc at main · erichelgeson/BlueSCSI

A small SCSI device based on stm32. Contribute to erichelgeson/BlueSCSI development by creating an account on GitHub.

github.com

 

[eric]

Also if it is that old please check the firmware version - and update to the latest. Easier said than done as it was before we had USB bootloader. We'll update and flash the USB bootloader for the cost of shipping if it was from any authorized seller.

Since drake was cheeky and removed the version number on his first order (before becoming a authorized seller!) It's hard to know if that is a b or a c - reading the doc he posted should give you the info you need to tell (if you get continuity between the 5v on the bluepill and the 220 resistor net, you'll know it's a c, if not it's a b and you should bodge (or make drake bodge and update it for you

 

[Drake]

@rjkucia I'm also keen on sending you a parts kit if you're able to solder?
Pm me if that's something you'd like to pursue

 

[Borgmac]

Here are some pictures of it - let me know if I should look at something further!

Sorry to jump in the middle of the discussion, but I do not see much solder on B12. Difficult to be sure as the picture is not focused on that area. May be you could make another picture focusing on B12?

 

[retr01]

Hi @rjkucia!

Looking at the picture more closely, I have found that some of those thru holes have not been filled. While the four holes for the side 4-pin 90-degree header may not be significant if you are not planning to use the Molex cable, some spots along the rows need to be checked. I have circled those in red.

I agree with @Borgmac that some areas in the picture are blurry, so unable to see all the holes clearly. I even thought maybe there was a fine bridge between a couple of spots on the back side for the 50-pin SCSI header, but perhaps just hair?

 

[rjkucia]

Thank you everyone for the advice & ideas so far! In no particular order:

Difficult to be sure as the picture is not focused on that area.

I can try to get a better picture later - my phone camera did not like focusing on something that close/small. My "real" camera should work better.

but just perhaps hair

Yeah there's some cat hair on it

I'm also keen on sending you a parts kit if you're able to solder?

I'm pretty novice at soldering but if we think it's just a matter of cleaning up those through-hole solders I can probably do that. Otherwise let me know what it would involve and how technically complex you think that would be.

Also if it is that old please check the firmware version - and update to the latest. Easier said than done as it was before we had USB bootloader. We'll update and flash the USB bootloader for the cost of shipping if it was from any authorized seller.

I figured it was out of date, and I checked the wiki but didn't see instructions for updating it. What's the process for updating this model's firmware?

I do recall there being a termination issue with the early revision of bluescsi and there should be photos pertaining to the bodge required on the wiki!
let's check:

From the link it sounds like this is only an issue for systems without TermPower (like the Mac Plus), and the bodge provides TermPower from USB power - is that correct?

I would assume that @Drake tested it since he build it

I assume he did as well lol - it *does* work pretty well with System 6, so if he tested with that it wouldn't have been caught unless he was doing heavy I/O testing. IIRC I did run a sort of disk check utility on this a while back, and it failed that test even on System 6.

 

[eric]

I figured it was out of date, and I checked the wiki but didn't see instructions for updating it. What's the process for updating this model's firmware?

Under the Flashing section it'll link to the updater repo - which will tell you what you need to know - jist of it is you need an ST-Link v2 to flash since you dont have a USB bootloader installed https://github.com/erichelgeson/BlueSCSI-Updater#bluescsi-updater

 

[rjkucia]

Under the Flashing section it'll link to the updater repo - which will tell you what you need to know - jist of it is you need an ST-Link v2 to flash since you dont have a USB bootloader installed https://github.com/erichelgeson/BlueSCSI-Updater#bluescsi-updater

Thanks! I don' t have one of those but it looks like they're super cheap so I'll order something like this: https://www.amazon.com/HiLetgo-Emul...1_2?keywords=st-link+v2&qid=1668524108&sr=8-2

 

[eric]

Yep, they're handy and lots of things can use it - something to have in the drawer

 

[rjkucia]

Here are a few more pictures - hopefully at least one of these is better than the first one lol

 

[JDW]

There's not enough resolution for me to determine if there is crud between the pins or if it is just blurring and lighting...

What I am forced to do whenever I use my iPhone 7 (yes, I'm poor) to shoot Macro photos is use my left hand to place a macro lens in front of the iPhone lens to shoot. For example, here are a couple shots on a totally unrelated SMD PCB...

1. With Macro lens in front of iPhone 7 lens, digital zoomed to 90% of max:


2. Raw iPhone 7 lens, digital zoomed to 90% of max:


Compared to my Panasonic G5 with Macro lens, the iPhone stinks. But the iPhone 7 photo with the Macro lens does allow me to get up closer to the tiny SMD chip. I do that all the time at work when I need to sent shots to the factory in Taiwan.