TD2TIP.008 -- TDD2/TDD1 Compatibility Test Results
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There is a fair amount of interest in TDD1-TDD2 disk compatibility. This
note reports some tests, conducted with DSKMGR.REL, and repeated with two
version of TS-DOS with the same results.

I've done the following tests, all with DSKMGR:

1. Started with disk in the TDD2 and used DSKMGR to format it. After doing
   List function of DSKMGR shows 202240K free.

2. Used DSKMGR to save a short file to the TDD2 disk in the TDD2 drive.
   Shows 200K+ free.

3. Moved disk and cable to TDD1. List shows 99K+ here. Loaded file into
   RAM from TDD2 disk using TDD1 drive. Ooops! I/O error.

4. Tried saving to the TDD2 disk in the TDD1: Worked fine. Put the disk
   back in the TDD2. Now only half the space is left.

Conclusion from all of this: Cannot load from a TDD2 disk with a TDD1 drive.
                             Can save to TDD2 disk with a TDD1.

Now try the same with a disk fromatted in the TDD1.

5. Used DSKMGR to format the disk in the TDD1. 101120K bytes free.

6. Saved file to TDD1 with DSKMGR

7. Moved disk and cable to TDD2.  List shows 99K+ free.

8. Loaded file from TDD1 disk in TDD2 -- successfully.

9. Saving file to TDD1 disk in TDD2: Get write protected error, even
   though is isn't!

So that does not work!

Then I repeated all the above steps using the two version of TS-DOS for
each drive, vers 2.01 for the TDD1 and vers 3.00 for TDD2.  Same results!

Bottom line is that you cannot:

   1) Load from a TDD2 disk with a TDD1
   2) Save to a TDD1 disk with a TDD2

Phil Wheeler -- 71266,125
7/19/87