DLC Screen Protection?

snail_Created: ~7 years ago

I looked at the ACLS help entry and noticed something interesting.

The screen protection feature based on add-on content is disabled.

This seems to me that loading the Namco DLC GRPs sets some kind of "protect" flag on the target page, so you can't do any GSAVE/GCOPY/SAVE with it. I checked the entry for DLCOPEN, but in the NA release it just tells you there is no Namco DLC. If you check the entry for GCOPY, you find this.

Images with protected add-on content cannot be copied, and an error occurs.

So far, so good. GSAVE?

Images with protected add-on content cannot be copied, and an error occurs.

Same thing. GSPOIT?

Images with protected add-on content cannot be loaded, and an error occurs.

What about saving GRPs? Nothing is mentioned under SAVE, but I'm certain it throws an error. So at some point, they added protections against copying DLC graphics. The same can't be said for the music and sprite definitions because they aren't loaded the same way, so they're probably fair game. GCLS doesn't mention anything about clearing the protection flags, but it probably does. GPUTCHR makes no mention of blocking if DLC graphics are loaded to the font page, so I guess that's one hole left open. Anybody with a JP copy got more info to confirm if this all actually works? Which error does it throw?

~7 years ago

ChangeV #2

It seems loading sprite (SP.GRP) and background (BG.GRP) set the protection flag. Font (FONT.GRP) is not protected and can be saved (tested with PACMAN)
for SAVE command if you try to save in program, you will get this error with line number. if you try to save in direct mode, you will get this error. (I will use direct mode for all other examples) (trying to load sprite into font page and saving the font page will produce error too) GCLS will NOT clear the flag and you will still get error. (and of course, ACLS will reset everything)
for GCOPY command GCOPY will produce error if you try to copy from protected graphic into unprotected normal page. (example: load sprite into page 0. try to copy part of it into page 1) but, GCOPY will copy normally if both source and target are protected pages. there can be more than 1 protected page, so copying into other protected page is possible. (example: load sprite into page 0. try to copy part of it into same protected page 0)
for GSAVE command it will not work.
for GSPOIT command it will not work.
for GPUTCHR command if you load sprite into font page then try to rip graphic by piece by piece..... it won't work. (I used FONTDEF to reset the font to see the result.)

pretty much everything is well protected... (of course, capture device like "Nisetro Video Capture Kits" can simply capture the screen shot.)

~7 years ago

haloopdy #3

Wow, thanks for the extensive info, ChangeV!

~7 years ago

snail_#4

Oh wow, this is some great info! So the protection is per-asset and not just because it's DLC, then, since font files can be loaded without protection? Very fascinating. Also pretty disappointing that GCLS doesn't clear the flag. I recall seeing that Protected resource error in an older bindump and not knowing what it means. Now I do! I just wish the error list was more complete. Which ERRNUM is it?

~7 years ago

ChangeV #5

all errors produce ERRNUM 49