Tools for analysing files

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pixelblip
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Tools for analysing files

Post by pixelblip » Sun Aug 09, 2020 10:24 am

Hi
What are the best tools on windows for analysing files types for the BBC?
I am trying to peer into files to get an idea of how they are made up. I've been using DFS explorer and Hex Mode but it's really hard to make out what the file does.
Sorry a general question just curious.
Thanks

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tricky
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Re: Tools for analysing files

Post by tricky » Sun Aug 09, 2020 10:45 am

*INFO and if the run address is &8023 or &801F, it is probably BASIC.
MODE 0 *LOAD 3000 look for graphics, patterns often means data or noise is usually code.

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pixelblip
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Re: Tools for analysing files

Post by pixelblip » Sun Aug 09, 2020 10:52 am

Thanks a lot.
The reason I ask is I am still trying to unlock the format of Movie Maker files.
I have spent many evenings staring at HEX.
Movie maker is very good at sprites in Mode7 - it has all the tools needed....but there is no picture import.
It means drawing everything on the keyboard.

What I was hoping was that I could draw pics on my teletext app on the ipad (backgrounds) and save them and load them into Movie maker.
The trouble is Movie maker works by splitting an image up into parts and it's knowing and understanding how it does this.

I can always use a traditional video editing package to merge two screens together but it's not the same as real animationa and real teletext.
I wish they had an import function in it for whole screens but it is just individual objects or sprites. So I am trying to decode that and it is hard going.

A few tried to help me before with it........
Last edited by pixelblip on Tue Aug 11, 2020 11:38 pm, edited 1 time in total.

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0xC0DE
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Re: Tools for analysing files

Post by 0xC0DE » Sun Aug 09, 2020 12:07 pm

I use HxD all the time on Windows: https://mh-nexus.de/en/hxd/
0xC0DE
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pixelblip
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Re: Tools for analysing files

Post by pixelblip » Sun Aug 09, 2020 12:19 pm

Cheers. I'll take a look.

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tautology
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Re: Tools for analysing files

Post by tautology » Tue Aug 11, 2020 6:59 pm

After hexedit died I moved to 010, which offers a template structure using a C type language so you can mark out areas. I also used this professionally for other reverse engineering (alongside Ghidra), enough that I ended up buying a licence.

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Re: Tools for analysing files

Post by julie_m » Tue Aug 11, 2020 10:51 pm

There's a lot to be said for using the video system as a diagnostic aid, by loading a file directly into screen memory -- especially now we're not using fuzzy CRTs anymore, but precise LCDs, where each individual pixel shows up with beautiful sharpness.
  • Graphics data will be pretty obvious if the screen mode has the right colour depth.
  • Text will have vertical lines going down it; all capital letters have bit 6 set, all lower-case letters have bits 6 and 5 set, most punctuation marks have both these bits clear.
  • With some practice, you can even pick out common opcodes such as &A9 for LDA#imm and &60 for RTS in blocks of instructions.

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pixelblip
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Re: Tools for analysing files

Post by pixelblip » Tue Aug 11, 2020 11:36 pm

Thanks a lot Julie. That's great advice.
In one way it's not so bad as we are dealing with Mode 7 and characters....but I can't understand alot of things.
Basically the shape has a name, corners ( I guess specified by characters wide by depth )and then the data followed by a byte to signal the end of the shape.
If I can work out how to make a shape that fits a quarter sof the screensize I can then possibly load a teletext screen into it. I am trying to find patterns in the shapes to see where the corner handles are for it. None of it makes sense at the moment looking at the files. I've been looking at pages of hex for days now :(

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