BeebEm does not seem to care about tape parity

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vanekp
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BeebEm does not seem to care about tape parity

Postby vanekp » Sat Apr 08, 2017 5:35 pm

Seems BeebEm does not worry about parity on tape data, I have an image of a BBC game (Psycastria) which has some special data blocks, now if i create an .uef image from the images (on beebem) i have extracted from the original so that I can reproduce a 100% copy of it I can load it without a problem in BeebEm but if i try to load it on a BBC it does not see the data from the special blocks which as far as i know has some other parity, not 100% sure which but think its 8e1 as when i make a uef i have to use -z 16 8e1 to decode the special blocks. Have noticed it with other tapes as well like Joust copy works on beebem but on a real bbc does not see the data.

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Pernod
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Re: BeebEm does not seem to care about tape parity

Postby Pernod » Sat Apr 08, 2017 5:42 pm

How are you loading the uef into a real Beeb? I'm not aware of any uef2wav converters that actually handle all uef blocks.
- Nigel

BBC Model B, ATPL Sidewise, Acorn Speech, 2xWatford Floppy Drives, AMX Mouse, Viglen case, etc.

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CMcDougall
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Re: BeebEm does not seem to care about tape parity

Postby CMcDougall » Sat Apr 08, 2017 6:51 pm

Use the .CSW for the actual beeb

not uef / hqUef as only 30% success...
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Coeus
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Re: BeebEm does not seem to care about tape parity

Postby Coeus » Sat Apr 08, 2017 7:13 pm

Is there info on the CSW format somewhere? I found the spec for UEF.

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hoglet
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Re: BeebEm does not seem to care about tape parity

Postby hoglet » Sat Apr 08, 2017 7:28 pm

Coeus wrote:Is there info on the CSW format somewhere? I found the spec for UEF.

My secret index of the interet suggests you try this for size:
http://ramsoft.bbk.org.omegahg.com/csw.html

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vanekp
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Re: BeebEm does not seem to care about tape parity

Postby vanekp » Sat Apr 08, 2017 9:05 pm

I have extracted the raw data for the tape blocks with a program and have my own program that then run from disc to either create a uef file if run on beebem or if i run it on a BBC i can capture the tape output directly to pc to get a high quality wav file. just find it odd that the same data works on am emulator but on a bbc it will not load special data on some games that have different parity on the data blocks.

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CMcDougall
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Re: BeebEm does not seem to care about tape parity

Postby CMcDougall » Sun Apr 09, 2017 9:51 am

^ could be your actual beeb, my Iss7s won't read 'stream' blocks at all, but Iss4s & 3 do.

try using Space Hi-Way by Amcom, Revs by AS, Stardrifter by Firebird & Mr Mephisto by Euro byte

Its not the LM324N chips fault at back of beebs, as swapped & same
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vanekp
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Re: BeebEm does not seem to care about tape parity

Postby vanekp » Sun Apr 09, 2017 8:13 pm

Don't think its the BBC as Matchday, Alien8, Fortress, NightShade, Wizador all work fine to mention a few protected games I have successfully reproduced and they work fine, I guess I am missing something with Psycastria that it wont start loading, I will just have to carry on digging.

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vanekp
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Re: BeebEm does not seem to care about tape parity

Postby vanekp » Wed Apr 19, 2017 7:55 pm

Now managed to make a 1 to 1 original working copy (created on the BBC written to a .wav file from images of the tape blocks) of Psycastria that runs on the BBC, the data from block 16 is 8o1 parity creating the tape image switching parity from 8n1 to 8o1 at the begin of block 16 it then works 100%.

Which proofs that BEEBEM does not care about parity as I was creating it with 7e1 as I though that was the correct parity and it still works on beebem but on not a real BBC.


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