The Sinclair QL Forum

M68008 wrote:Based on Andrew's experiment, the two versions of the cartridge seem compatible as far as the copy protection goes.

I should be able to merge them into a single working master copy.

I'd love to know how that's done. Because we don't actually know what the copy check is checking for. Will you establish what the copy check is checking for and then make sure that feature is part of a new file?

Andrew wrote: It's compressed plain text, with some sort of a header, with a very simple compression scheme: all characters over 128 represent a group of 2 or 3 characters.
I have not checked all files, but for the file "people" the mapping is like this:

chr$(136) = ma
chr$(149) = ght
chr$(171) = ite
chr$(175) = ess
chr$(177) = ard
chr$(190) = en
chr$(211) = ie
chr$(201) = of
chr$(205) = an
chr$(206) = am
chr$(207) = ar
chr$(214) = ll
chr$(215) = ia
chr$(223) = d_ (d and space)
chr$(224) = n_ (a and space)
chr$(227) = t_ (t and space)
chr$(230) = pi
chr$(237) = be

Thanks for that.

Chr$ wrote: I'd love to know how that's done. Because we don't actually know what the copy check is checking for. Will you establish what the copy check is checking for and then make sure that feature is part of a new file?

The basic idea is to only copy over the damaged file sectors, leaving everything else alone.

In this case, the cartridge is so damaged that entire sectors are missing from the image, so I will first create a duplicate image with all sectors present.

I'll probably add commands to MdvMerge to perform these operations.

Here is the restored master cartridge: I also looked into the copy protection and it checks that sector 0 has not been changed.

Initially, copying the files from the backup to the master didn't work: it turns out that the file 'cross' has different contents! It's probably a key file that contains information matching the contents of sector0, and sector0 and the key file must have been different in Rich's copy. Overwriting the master cartridge files with those from the backup (while leaving the microdrive map unchanged) with the exception of 'cross' resulted in a working copy.

You've all jumped a bit ahead of me. I got the RWAP version to run yesterday, by doing a live patch with Qemulators debugger.

As Daniele says it does some kind of checksum of the microdrive map. In Chr$ game image, I altered the map when I repurposed two unused sectors to replace the missing sectors. Just to be neat and tidy. And so shot myself in the foot.

As for the two different questions images. I was wondering if there is more that one questions cartridge. It would make sense for Talent to be able to release new updated trivia questions. Leaving the main game the same.

I will have to see if I can patch Chr$ questions image together, and see if it's recognized.

Great work everyone - at least this one is now recovered and up and working.

I will check with Tom, but cannot see any reason why it cannot be released as public domain

Bit late to the game with this one. Just found a short review of Oxford Trivia in QL World June 1987. Attached, as scanned PDF. An advert in the same issue shows it being sold by TK Computerware for £18.00

dilwyn wrote:Bit late to the game with this one. Just found a short review of Oxford Trivia in QL World June 1987. Attached, as scanned PDF. An advert in the same issue shows it being sold by TK Computerware for £18.00
Oxford-Trivia-Review.pdf

Interesting. The ad mentions a further 16 question categories. My questionable questions cart has 22, so I'm still not convinced it belongs to Oxford Trivia.

Thanks Daniele, Martin, Andrew. It's great to see something up and running again that was previously lost to time.

Chr$ wrote:Interesting. The ad mentions a further 16 question categories. My questionable questions cart has 22, so I'm still not convinced it belongs to Oxford Trivia.

I was having a look at your questions cartridge to see if it's possible to recreate the three or four damaged sectors. By figuring out the way the question files are organised. And try to fill in the blanks. But I think you are right, that this cartridge does not belong to Oxford Trivia.

If you COPY FILE1 from the RWAP cartridge to the screen. You can see that the file looks nothing like the files on your questions cartridge. The file looks like it's been compiled. There are SuperBASIC keywords in it and a reference to FLP1_. Also if you try to use your questions cartridge, The game throws up a Pascal error.

Also Daniele's patched program, and Andrew's work round. Don't work on the old (V3.1.4) copy of Qemulator on my PC. It works OK on V3.3.1

Martin_Head wrote: Also Daniele's patched program, and Andrew's work round. Don't work on the old (V3.1.4) copy of Qemulator on my PC. It works OK on V3.3.1

Probably related to a tape emulation fix I did just after 3.1.4 for programs that read sectors without reading the sector header first.

I have done a copy protection patch bypass for Oxford Trivia.

It works OK in my old Qemulator. I have also created MDI and QLAY versions.

I tried the mdi version in QPC2, But it hung when it says insert the original mdv message. I don't know if I got something wrong, or the game does not like SMSQ/E