• Please review our updated Terms and Rules here

Macintosh Plus 1Mb question -- boot from floppy emu

Dokken

Experienced Member
Joined
Feb 27, 2018
Messages
249
Location
TN
I picked up a Macintosh Plus from craigslist. When I got there to pick it up the lady said it just stopped turning on. it would chime but nothing on the screen. She asked if I'd give her $20 for it. has keyboard and mouse and is pretty clean.

I change most analog board electrolytics, had it showing the boot screen for a period, then no display. turned out the be cracked/cold solder joints on the connector that goes to the main board. it now boots reliably.

I have no Macintosh boot floppies.

I have a couple of other old Macs but am a nooby on using them (never owned one for use). I have an SE/30 and a Classic if they would be of use in making floppies. Also have a floppy emu and blue scsi.

With my Classic and SE/30, the floppy emu works great. plug it in, select a system disk, and it boots. I tried the same with the Plus using several OS images. System 2 (and possibly others) will change from a question mark floppy to a smiling floppy. The floppy emu will do its accessing then go to idle, but it does not load the OS.

Am I doing something wrong? or are there other things I can check?

thank you.
 
Just curious why your title says Plus 128? Those are two very different computers. I assume you have a plus. The floppy emu should work just fine one it, the Floppy emu works fine on my MAC plus models. You may have an issue with the external connector. Have you tried plugging the ribbon of the floppy emu into the internal connector?

IF that worked and you were able to boot, yes you coud use an SE or Classic to make disks compatible with the plus.
 
oops. it says Macintosh Plus 1Mb on the back label. my mistake.

I have tried the floppy emu on the internal connector and the external, same result.
 
Yeah its just a MAC plus.. They all came with 1MB. And you are definitely trying to load an 800KB or 400KB disk image? Not the high density disk images? Try with the mouse and keyboard disconnected in case of possible short. If it still doesnt load you have a hardware fault, possibly IWM/Swim chip.
 
I notice this resistor is cut.
 

Attachments

  • macplus1.png
    macplus1.png
    2 MB · Views: 15
success! reconnected the ram selector resistor.
 

Attachments

  • macplu3.png
    macplu3.png
    560.7 KB · Views: 4
thats nuts why would it have been cut?!
This resistor is disabled when using RAM SIMMs larger than 256k, so it would have been cut when a previous owner upgraded the RAM beyond the factory 1MB. @Dokken - seeing that you've now got 2.5MB installed (looks like 1MB SIMMs in bank A), that resistor at R8 should remain cut....

As for the Floppy EMU - did you get it working? It won't work with the Plus in 1.4MB mode, just 400k and 800k
 
2.5mb, does this seem correct? resistor is still connected
 

Attachments

  • macplusmem.png
    macplusmem.png
    957.6 KB · Views: 5
Back
Top