'xemag fat tracks on a c128d'
Author:J Achernar (registered user: 36 posts )
Date: Fri, Nov 18th, 2011 @ 22:15 ( . )

I have finally had a chance to step through Tass Times to completion to see if it does any additional copy protection checks after startup, and can verify that it does not. With my 36 track D64 image, I made it to the end of the game without any problems. Side 1 of the original floppy included an XEMAG fat track. Side 2 was not copy protected.

To run the program in VICE, true drive emulation must be enabled. Also NTSC mode should be selected. It will work in PAL, but the title tune will play too slowly (HVSC file is NTSC). Either setting for the CIA chips, old or new, works.

When my 36 track D64 image of side 1 is run under VICE (x64sc v2.3), the drive slews to track 35, then to 35.5 and back to 35 before continuing to load the program and showing the title screen. After a bit, it requests insertion of side 2 and then starts the game. Side 2 is then used for the entire game.

When I try to run it as a 35 track D64, the drive slews to track 35, then to 35.5 and then to 36 and hangs.

I have not been able to get the D64 image to start on either CCS64 v3.8 or HOSX64 v1.0.7.2 (after padding to 40 tracks). They hang just after start up (at track 35 for CCS64) and never reach the title screen. I have also made two G64 images, one with only full tracks, and one with all half tracks. Both G64s work identically in VICE. With these, the drive slews to track 35, then to 35.5 and then to 36 and then continues to successfully load the program. CCS64 only works with the half track image. HOSX64 does not work with the full track image and does not support the half track image.

I have looked at the D64 image of my backup floppy and verified that it matches the original. I never made a NIB of the backup.

I have not tried to get under the hood and don’t know why a 36 track D64 satisfies the copy protection check under VICE, but not under the other emulators. For EA’s Music Construction Set with a fat track, a G64 image is required to run it under VICE and even then it takes two full loading passes to satisfy the check.

Hyper active, making another floppy backup of the original is still on my to-do list. I will post the results when I finish it.

Lord Crass, I don’t believe VICE actually does read half tracks correctly. It does work with fat tracks (at least sort of), but I believe that is just sends the data from the nearest full track. It works the same with fat tracks whether or not the half tracks are included in the G64 image. I have made them both ways. For a little more on this, see my comment in the thread “Fat tracks in emulation”.


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--* xemag fat tracks on a c128d
11/19/2011 @ 22:55--Nate
11/07/2012 @ 20:06----hyper active
11/07/2012 @ 22:35------hyper active
11/13/2012 @ 23:13--------hyper active

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