Tetras

Use this forum to submit new files for the download section of the archive. I will check each submission and upload it to the archive on a regular basis.
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Sarah
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Tetras

Post by Sarah »

I noticed that the copy of Tetras in the archive seems to be cracked, with the loader & loading screen removed, or perhaps originated as a raw file sent to a disc user. It also has an ?IO ERROR in the final block for some reason although it does seem to run okay with EXEC.

So just leaving a complete/original format copy here for now. I'm pretty sure this loaded okay with T3 although I spent some time trying it with Xroar Online tonight without success, even when padded with extra leader bytes in a few places. I'm not sure if the issue is just the leader bytes, the multiple non-standard block types & lengths that it uses, or perhaps another reason. Inserting leader bytes before blocks 7 and 32 does seem to help, although doing that at another likely location around block 16 actually seems to make things worse instead, or is unusually critical... I don't remember exactly how the loader works, but there are 3 main phases (initial standard text/autorun part, a brief semi-graphics display whilst the 'Gorbachev' picture data loads, then it switches to PMODE 4 whilst the game loads). I'll upload a replacement if I make progress with Xroar compatibility another day...!

If you play the game, pressing 'C' or 'B' on the title page chooses colour (semi-graphics) or black & white (PMODE 4) display option.

Edit: Now updated with correctly fixed and trimmed copy! :D
Attachments
TETRAS.CAS
TETRAS.CAS by Sarah Burgin
(25.38 KiB) Downloaded 34 times
Last edited by Sarah on Tue Jun 23, 2020 8:53 pm, edited 1 time in total.
sixxie
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Re: Tetras

Post by sixxie »

Here's a hack of that that loads in XRoar. Here's how far I had to get to make it load:

### File 1

"Long save" over CHRGET, vectors and basic command line.

Loads $00a6-$03ea inclusive.

Points CHRGET to $02f3, which contains (tokenised) :CLOADM

AFAICT no vectors pointed to anything crazy.

Returns to BASIC, that CLOADM is then kicked off.

### File 2

Starts with a long header block (255 bytes).

Filename is: 08 1f 08 04 20 03 07 08
Binary.
Load to $0167, exec $10ce.
Followed by extra data

but... the next block come in as a filename block only 2 bytes long.

There were no leader bytes after the checksum byte of that block - inserted a run and voila!

I can see that there was more to work through there, but that's all that was needed to get XRoar happy with it.

Edit: run that through tape-rewrite. Looks ok!
Attachments
TETRAS.cas
(26.95 KiB) Downloaded 31 times
sixxie
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Re: Tetras

Post by sixxie »

Ooh you can play in colour! (Yeah I saw the word "COLOUR" in the tape image and got curious). That looks excellent - how come it wasn't the default?
Sarah
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Re: Tetras

Post by Sarah »

Awesome, thank you! Nice to see it working properly! :D

The hires graphics were implemented first and stayed default as I still preferred the extra detail. You're right though, I should've at least mentioned the colour option on the title page instead of leaving it as an Easter Egg!
sixxie
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Re: Tetras

Post by sixxie »

I know Windows users don't get to see this (yet - I'm slowly working out how dialogues work in the Windows API), but here's XRoar getting confused about your non-standard block types:
tetras-file-list.png
tetras-file-list.png (32.32 KiB) Viewed 829 times
Sarah
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Re: Tetras

Post by Sarah »

Haha, cool!

Looking at your analysis, I've realised that 'File 1' on this copy is actually some kind of quick-fix or tweak that can be skipped. Its purpose might be to change the PMODE 4 colours in PC-Dragon II or work around something emulator related (sorry, can't remember or check right now; if no code runs then it was probably just to insert a recognisable/matching filename); in which case it wouldn't have been on the original tape.
.mad.
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Re: Tetras

Post by .mad. »

The loading screen with the Dragon birthmark made me chuckle. :lol:

Thanks for the original upload and fixed version.
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Sarah
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Re: Tetras

Post by Sarah »

Thanks. It was kinda disrespectful, but I'm no artist so still quite proud of that screen! :D
Sarah
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Re: Tetras

Post by Sarah »

Updated the first post attachment with a fixed and trimmed file!
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