Unidisk 3.5 compatibility

[fimbulvetr]

I was hoping to be able to use my SE/30 as a stepping stone to get software for my Apple IIc, but I seem to have run into a compatibility problem. I'm using DS/DD 3.5" disks, but 800 kb disks formatted on the Unidisk 3.5 attached to my IIc are not recoginsed by the SE/30 and vice versa. Does anyone know if these disks should be compatible or not? Too bad that the Unidisk drive cannot be connected to the SE/30, as that would be a simple solution to the problem.  Thanks!

 

[Elfen]

In the "newer" Systems (7.5 and on) when you format a disk, you have the option of Macintosh, MS DOS, and Pro DOS. You need to make sure the proper extensions are loaded in (PC Exchange and other helper extensions).

 

[ScutBoy]

Are they formatted with ProDOS? You may need an extension or two to be able to read/write them on a Mac.

Might just be the "PC File Exchange" extension/Control Panel, but could be different depending on the version of System Software you are running on the SE/30.

If they're not ProDOS, then I don't have enough info to tell you how to proceed....

 

[Elfen]

They need to be ProDOS. Apple II 800K drives can't read anything else. There was a IIgs Utility that will read a 800K PC Format Disk but details on that is sketchy at best.

Damn thing is, the formatting is the same between Mac 800K and ProDOS. Its the sectors themselves that are different. That's why they cant be read on either machine without proper extensions on them.

 

[fimbulvetr]

I formatted them with AppleWorks 2.0 on the IIc. The SE/30 is running System 7.1 with update 3. It gives me the option of 800 kb or PC 720 kb when I format a disk with it. 

 

[olePigeon]

You should be using ADTPro with your more recent computer.  Connect a serial cable or from your computer to your Apple //c's serial port, then follow the directions.  Alternatively, you can even use the audio port if you don't want to deal with serial connections.

If you want to use your SE/30 just because it's fun, then you'll need to track down a copy of the original ADT for System 7.  Hopefully someone better at Google can find it (or if they have a copy, post it.)  Works nearly identically to the most recent version.

 

[Elfen]

I formatted them with AppleWorks 2.0 on the IIc. The SE/30 is running System 7.1 with update 3. It gives me the option of 800 kb or PC 720 kb when I format a disk with it. 

As i remember, System 7.1 does not have the ProDOS option formatting. System 7.5 should, I know it does on system 7.5.5 on my PB 190.

You could take the PC Extensions from a System 7.5.5 and put it into System 7.1 but I doubt that will work.

 

[fimbulvetr]

I wanted to use the SE/30 and disks because it seemed easy compared to getting/building a serial cable and messing about with connecting computers that are on opposite sides of the house.  Sneakernet!  PC -> SE/30 -> IIc

 

[Elfen]

What other Mac you have? Until you get that SE/30 upgraded to System 7.5.5 or juggle extensions about, this might be a hard proposition to fulfill.

 

[fimbulvetr]

I have a Classic II and a Cube, so no help from either of those.

 

[Gorgonops]

To back up a little: what are you trying to do again? Are you trying to format a "data disk" and drag Apple II programs to it on the SE/30? As noted, that just isn't going to work unless you have a ProDos file extension installed.

However: if you can find 800k ProDOS disk images in DiskCopy format you should be able to generate usable disks. The problem there mostly comes in finding software in that format; it seems like most of it on the web is in the "Universal disk image" format generated by the "Asimov" software for the IIgs and widely used in emulators. It *may* be possible to convert the .2mg files to Diskcopy format, but don't ask me the best program to use for that. Alternatively, if there's an emulator that can deal with DiskCopy format you could do something arduous like:

1: Format a blank Prodos disk on your IIc

2: Image it with Disk Copy 4.2 on your SE/30

3: Transfer the blank image to something powerful enough to run an emulator, mount a copy of it in a virtual drive, and use the emulator to copy programs onto it.

4: Copy the populated Disk Copy image back to the SE/30

5: Write it back to a disk.

6: Cross your fingers and see if it works on the IIc.

Maybe the program Ciderpress would be of some use in generating a usable Disk Copy image?

 

[fimbulvetr]

I was exploring all of the above possibilities.  I've been using Ciderpress and HFVExplorer on my PC.  I got stymied at the step where I put the IIc formatted disk into my mac. I guess I should look into getting the prodos file extensions installed or getting a serial cable.

Macs certainly can be mysteriously confusing creatures!  Most of my 1980's vintage computer experience is with ancient DOS computers and ti99/4a's (which is surprisingly straightforward for a 35-year old system)

 

[olePigeon]

You can also use an audio cable if you're intimidated by the serial cable.

 

[Gorgonops]

You can also use an audio cable if you're intimidated by the serial cable.

IIc's don't have cassette jacks, so that only works for IIe's and older.

(I've been using the snot out of the Apple II Disk Server generating disks for my II+. I do have a serial card for it but it's missing the dongle so, well, audio is the lazy solution.)

 

[NJRoadfan]

The Unidisk 3.5 should work with any 800k formatted ProDOS disk. For best performance they should be formatted for 4:1 interleave. By default, Macs likely format them at 2:1 or 1:1 interleave. Formatting them in a Unidisk should give the desired 4:1, and ProDOS should install boot blocks.

The SE should have PC Exchange or the older "ProDOS File System" extensions installed (comes with the Apple IIe card) to natively mount ProDOS disks.