Jump to content
Opry99er

Red Baron/SPAD XIII docs

Recommended Posts

Here's what the copy protection looked like on Red Baron back before it was put on cart... :)

 

Anders actually figured out some of this protection that Larry Hughes with Quality 99 Software did another variant of before. It was actually pretty ingenious... and he changed/improved it with Red Baron Flight Simulator on disk. Copy-C, if it was available back then, could have easily just copied the whole disk.

 

PC99 vs Red Baron.pdf

Share this post


Link to post
Share on other sites

I remember breaking the protection on SPAD13 mk2 by a much simpler method. The program is in 2 Xb programs: the first segment loads 8K into low memory and then runs the next program, which loads 24K into high memory. All I had to do was to first run the XB program that loads the low memory segment. (This is very slow because of the sluggish XB assembly loader.) Once the 8K is loaded the protection scheme cannot interfere - the code is already there! With the assembly code in low memory, it was easy to write a systex like loader that embeds the entire contents of low memory into an XB program. When that program runs it loads the 8K segment into low memory, then runs the high memory XB program which is all embeded code. It may be that the second program was protected by hiding the line numbers, but that is easy to defeat.That's all there is to it!

This is the version of the program that is posted on GameShelf.

 

(Edit) - I just dug out SPAD13 mk2 and tried it out. My memory was pretty close. It does not use the XB assembly loader after all, so the 8K segment loads faster than I remembered. It takes a while to load the second segment and during that time you just have to press and hold Fctn 4. The program will break before it starts up. You can list it and see one line of code. (the rest is embedded) You can save this program as PART2. Then type NEW - the code that was loaded into low memory is still there. Then OLD DSK1.PART2 and the high memory part of the program is loaded. Type RUN and it starts right up, using the already loaded code in low memory. So that shows that you just have to find a way to save the low memory as PART1 and the protection is defeated.

Edited by senior_falcon
  • Like 3

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...