IIgs does not see anything but 5.25 drive

[mpfjr]

Messing around where I shouldn't have I was making my own cable for a Duo drive that I found at a garage sale without cable.  Easy enough to make a cable but I could have made a mistake?  Anyways let me tell you how this all went down and maybe you can tell me that my IIgs can be saved.

So I've been playing around with ADTPro the last couple days when I had time to sit down.  I was making disks and what not.  Well this morning I decided next on my list was getting that DUO drive that has been in a box for a month or so working.  All it needed was a cable.  I found the pin-out guide online and so I found a db25 double ended cable I have plenty of ( I have maybe 10 of these cables) and snipped off one end.  Then I exposed all 25 wires and matched up the colors with the pin assignments.  Then I took the DB19 end that I got from amazon and started soldering each wire where it goes. 

Once I was done I connected it to the IIgs, turned it on,  IN#2 - Control A  -  14B and then started up ADT Pro on my PC and connected and started prodos quick boot.  It booted up no problem and I then placed two blank 5.25 disks into the two drives and formatted them.

Initially drive B was giving me problems.  It would say check disk or drive door.  Then it would say disk write protected.  Tried a few more times, rebooted and started everything over again and it all worked fine!  I was able to format both disks from each drive and I copied over  disk 1 and 2 of Conan halls of volta.

Considering that a success I got out my floppy EMU with daisy chainer.

I plugged the daisy chainer into the back of the iigs, plugged the floppy emu ribbon cable onto the top and the duo drive into the 19pin slot at the rear.

Booted up .. can not find start disk or whatever the language is.  Oops, I had it in smartport unit 2 from a few days ago. Ok, put it back into smartport disk (floppy emu) and tried again.

Still would not boot up.

Ok, this is weird.  Remove the duo and try again.  Still does not find any device.

Hmm, ok remove the daisy chainer and go back to the regular 19pin to ribbon cable adapter it came with.  (floppy emu)..  Fire it up and still can not boot/find device.  Ok now I am getting worried...

Thinking maybe I zapped the floppy emu, I flash the firmware to mac mode, put it on my mac and it worked fine!

Flash it back to Apple II

Ok maybe there is a bad smart0.po file.  So I used my backup disk.  Still no go. 

I then put it into 3.5 800k mode, still will not boot/load any .dsk file Nothing happens at all.  Says no device found.

BUT when I put the floppy EMU into 5.25" emu mode, it loads stuff just fine!

So as a sanity check I got my physical 5.25 drive (not the duo) and plugged that into my iigs.  The disks I made boot fine.

So then I unplugged that one and put my 3.5 on there alone.  No light comes on, no disk access, nothing.  no device found.

BTW, I am turning it off and back on after I make these changes.  Just so you understand I am not hot swapping anything.

Theory, my soldering job on the duo cable may have left a strand of a wire not tucked in and it may have shorted across a two pins and burned up the IWM chip in some way.  Or at least in whatever way that prevents anything above the 5.25" drive controller from working.

It is like a slot issue or something.  I checked the slots in control panel. They are correct and default.

Someone suggested a low battery can cause weird things to happen so I removed the battery. It tested at .3 volts.  Not 3.0 volts but .3.  Yikes.

I unplugged the machine and gave it 20 minutes without power and tried it again (not sure why I thought that would do anything) and still same result.

So I am guessing I am going to need a new IWM chip which is the square soldered on 344S0041B VTI chip. 

 

[joethezombie]

Since 5.25 drives work fine, the IWM is most likely working as it should.  More than likely, especially if your were hot plugging drives, or speculate shorting pins, the VGC has been damaged.  It provides the HDSEL and 3.5DISK lines.  I was never able to find a replacement chip alone, but a sharp eye on eBay I found a complete replacement logic board for $15.   I decided to leave well enough alone, and not transplant the chip.  As such, I can't qualify that the VGC was the culprit.

 

[mpfjr]

I just read that thread  thank you for posting it.  Yep, that is exactly what I have going on but I don't know what the VGC looks like. I'll try and figure it out.  In the mean time, if someone has a iigs board that works they want to sell me cheap, get in touch?

 

[joethezombie]

VGC is a PLCC located under the power supply at position UF2.  Should be marked as such on the silkscreen.  Depending on your revision, it can either be socketed, or soldered directly to the logic board.  Best of luck!

 

[mpfjr]

Socketed.  I have AMI 344S0046-2

So the video controller has control of 3.5 ports?  What about smart port because that isn't working either.  Someone said on facebook that the smartport uses 5.25 part of things so if the 5.25 is working then the smartport should work.  Can anyone confirm this?

 

[joethezombie]

So the video controller has control of 3.5 ports?

Yes, among some other non-video related signaling-- it's a multi-purpose part.

I'm not an expert on Smartport, and I stopped troubleshooting after the replacement logic board worked.  It is my understanding that the HDSEL line is instrumental in identifying Smartport devices prior to assigning a Smartport address.  Corrections welcomed.

 

[mpfjr]

Well I mean it is kinda good news and kinda bad news I guess. I still need the chip but since it is socketed and I have the puller I should be able to remove it and replace it with another.  But the bad news is that I can't find one.   I need a damaged or non-functional iigs board to pull one from.  This might take me a while.  You seem to have taken all the good luck with your rom 3 $15.00 board. 

 

[mpfjr]

Yes, among some other non-video related signaling-- it's a multi-purpose part.

I'm not an expert on Smartport, and I stopped troubleshooting after the replacement logic board worked.  It is my understanding that the HDSEL line is instrumental in identifying Smartport devices prior to assigning a Smartport address.  Corrections welcomed.

I did the same thing you did Joe, I just bought a new board. Got a Rom3 with a Woz edition top cover.  Now I can take my time and find a $15.00 board on ebay like you did and get the broke one up to 100% again and re-sell it to recoup some of my costs.  Thanks for all your hard work and help.  It was very much appreciated.