Mac Plus & scsi2sd bizarro behavior.

[chu-oh]

I've got a weird issue with a scsi2sd and my mac plus. I followed this guide http://www.codesrc.com/mediawiki/index.php?title=HFSFromScratchand setup the scsi2cd with the suggested mac plus settings, but I'm getting some weird behavior. 

When I try to boot from the scs2sd one of 2 things happens, either I get a blank white screen or it a weird pattern ( looks like an untuned tv) with a repeating clicking noise. I thought it could have been caused by some old capacitors so I recapped the analog board, but it's still happening. 

Any thoughts? It doesn't do it when the sd card isn't inserted so I'm guessing it could be an issue with the way I've formatted the SD. Unfortunately I don't have any floppies to test with. 

 

[chu-oh]

So interesting enough I realised that BasiliskII was using a MacIIc rom and this was used to make the bootable image, I figure maybe System 7 is installing specific drivers for that computer, hence the garbled screen and the weird behavior (could be way off here). So I tried Mini vMac with a Mac Plus rom to do a System 6.0.8 install on an image and then write it to the sd card - completely different results: grey screen (no flashing on scsi2sd) then flashing question mark (the scsi2sd then constantly flashes). So this is more along the lines of what other people have experienced with the scsi2sd and the plus. My plus is a very late model plus so I'm hoping it's got the 3rd revision rom.

I'll double check the scsi2sd settings next and see what the utility log says is happening when it's flashing at the question mark stage. I found someone selling an original full set of System 7 800k floppies on ebay - hopefully these will come in handy too. 

 

[tjjq44]

Apparently, it isn't possible to boot a plus from scsi2sd... (many threads about this in the forum)

 

[chu-oh]

Yep looks like it - I figured because I have such a late Plus (serial number lookup says May 1990) that I should have the 3rd rom revision and I may have some better luck. 

When I bought it it came with a scsi drive - but it failed and I stupidly threw it out. But it did boot from that. 

Still I can't make heads or tails out of the screen issues I'm getting when trying to boot, done a lot of digging and can't find anything similar, even in the Dead Mac Scrolls.  

 

[techknight]

Does it do this when you remove the SD card, but leave the SCSI2SD in place? 

 

[chu-oh]

Nope! Only does the bizarro screen stuff with a drive formatted as per http://www.codesrc.c...=HFSFromScratch.

I did try with Mini vMac and 6.0.8 and it does the same thing.

 

[techknight]

That answers my question. 

The problem isn't the SCSI2SD, the problem is the disk driver written to the SD card itself. Best thing to do IMHO is use a DD image clone of a good known hard drive that works with the plus. 

This issue happens with Iomega zip disks too, there is a specific and older zip disk driver that works with the plus but newer ones dont. 

 

[chu-oh]

Ok thanks for your help. I don't have a working drive to clone - but my install disks just arrived so I'll how I go formatting and making the scsi2sd disk bootable from the patch version of disk tools. 

 

[chu-oh]

No joy unfortunately. I managed to get the System 7 installer to see the drive (by inserting the micro sd just after the happy mac) and it went through and installed, but on reboot it just did the same screen pattern loop.

Interesting enough if I try doing the same process with the Disk Tools disk the screen gets stuck and garbled at the welcome to Macintosh window - all very odd. But it must just be the drivers supplied by hfdisk. 

About to give up on this little project, I might order a 6.0.8 disk and the utility disks from Rescue My Mac as a last ditch attempt to get this going. I know I can probably solve all my issues by going with a Floppy Emu - but I'm not keen to waste any more money.

 

[CharlesT]

Are you using a V5 or a V6 scsi2sd card?

 

[techknight]

This almost makes me want to break out mine with my Plus and figure it out... 

 

[chu-oh]

@CharlesT V5 scsi2sd. 

@techknight - I'd love to see if you can replicate what's happening with mine. 

 

[just.in.time]

The Plus has a strange implementation of the SCSI protocol. Most of the time, not an issue. Except for when it is. Also, your partition sizes are less than 2gb right? I usually aim for 1.9gb to play it safe. Never seen your screen issue while using Zip disks. Never tried my SCSI2SD with my plus.

I’m pretty busy already this week, but post back if you haven’t figured it out next Monday. I have the older zip drivers and have made several bootable Zip disks for my Plus. I could probably do a clean install onto a Zip disk then use my G3 to make an image of the disk via dd. It would probably only be 10mb or so, easy email. Then you would just do as Techknight said in regards to using dd to write the image.

 

[chu-oh]

Yep tried lots of different combinations (as low as 20meg), if you could make an image that would be amazing. 

I've ordered the disks from rescue my mac, but it's going to take a week or 2 to make it to 'Straya.

 

[chu-oh]

So a minor update: I spoke to Michael who designed the scsi2sd and he seems to think it could be the cheap cable I'm using (it's a 2m serial cable not even a scsi cable) so I'll source a legit scsi one give that a go.

 

[68krazy]

If I’m not mistaken, Michael McMaster is from Australia as well?

He has been very responsive to the community regarding SCSI2SD issues and suggestions over the past few years. Seems like a really great guy! Also, I’m guessing, something of a SCSI guru at this point.

 

[techknight]

So a minor update: I spoke to Michael who designed the scsi2sd and he seems to think it could be the cheap cable I'm using (it's a 2m serial cable not even a scsi cable) so I'll source a legit scsi one give that a go.

you CANNOT use a serial cable! we could have avoided the whole rigamaroo of this thread if that was mentioned in the beginning. They are wired very differently. I remember trying one way back in the day when I was new and green, ended up losing the SCSI IC from it. 

 

[chu-oh]

you CANNOT use a serial cable! we could have avoided the whole rigamaroo of this thread if that was mentioned in the beginning. They are wired very differently. I remember trying one way back in the day when I was new and green, ended up losing the SCSI IC from it. 

Oh my I feel like an idiot! I didn't even realise it was a serial cable until Michael pointed it out after I sent him a link to the ebay listing, I very naively thought DB25 meant scsi. I should have known anyway as I used parallel port printers for years in the pre usb days.  Still super weird that I was able to install to the drive. Anyway I'll sit here in the corner with my dunce hat on for a bit
 
So today I went through a box of stuff I had in storage at my old place and found an actual scsi DB25 to centronics cable and the centronics to internal ribbon cable that I pulled from the original scsi drive that died (could have avoided all this if I bothered to look for these first sorry). I briefly tried the scsi2sd and the Mac Plus with this this afternoon, I'm not getting the reboot loop, but the drive isn't appearing as an install option on the Install 1 disk. The scsi2sd does flasheswhen I try and run the unpatched Apple HD utility disk - so I think it's at least being detected. I'll have a patched version in the next couple of days so I can format the drive with that and see what happens once I install to it. 

 

[techknight]

Well hopefully with the right cables and utilities, it will all work out.