I sometimes use 20090304 instead of 20141107 for downwards-compatibility (e.g. TR+AF behaves differently in 20130803 and newer builds etc.) and because we had dualSID support cut out in the public 20130803 version at that time.
Notice 1 - the lack of end-pattern marker (red dots) bug always coexists with no copy+paste pattern bug (shift+N = the screen flashes red but nothing happens). I guess they are connected somehow (defMON not being able to recognize start+end of the pattern to copy because of missing end-pattern marker?). It also causes the affected pattern to skip (jump to next pattern) prematurely/at random.
Notice 2 - the bug will never happen if you start a new tune. It always happens after you load a tune from a disk. It looks like the end-pattern marker is not written to unused patterns. And after loading a tune from the disk it's simply not there because defMON doesn't automatically fill end-pattern markers into unused patterns.
To reliably reproduce it: 1) Start editing any tune. 2) Save it to disk. 3) (optional) Restart your C64. 4) Load the tune from the disk. 5) Voila.
No red-dot markers in any new pattern. And no copy+paste possible.
A quick video (edit: corrected link):
http://youtu.be/uSNeIQdu7WU
Solution I tried:
I hoped that in both 20090304 and 20141107 it would be possible to work around the bug by copy+pasting existing empty pattern (00) with the end-pattern marker into new pattern that became corrupted (force override). That would be easy solution but when the bug happens - copy+paste doesn't work at all either (the border flashes red color only but the pattern is not copied - like at the end of the vid).
It happens both on real C64 (10+ different mobos+chips tested dating from 1982 up to 1993) and in emulated environment (Vice/CCS64/whatever) but I really don't think it's cycle/hardware-related issue.
Last edited by F7sus4 (Oct 26, 2017 5:36 am)