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tlr
Registered: Sep 2003 Posts: 1787 |
Release id #40365 : 25 x Turbo
Does anyone know the origin of this code...
Info:
Turbo at $e000-$e88d. ($e406 called by the small init at $014b)
Trackbuffer $e900-$fdff.
Transfer decode buffer $fe00-$ffff.
Quick analysis:
Init:
* There is no init except setting up the load vector.
* The load vector points to $014b.
* The routine at $014b copies some kernal routines ($ed00-$f0ff) to
ram under kernal and then jumps to $e406.
* At $e406 the filename is checked for '$' and device numbers below 8,
at which it skips out to $f4a6 for normal load.
* $e42c, print searching...
* $e433 loader init starts.
Loader:
* $e457 copy bootstrap to drive
At $e817 the drive code is stored, pre-M-W-encoded. Each command is
terminated with a $ff marker, and the last command is terminated by
an additional $ff marker.
This code is just a small bootstrap ($0706-$075f) waiting for the
rest of the code.
* $e489 copy the real drive code by high speed transfer.
Copies the code $e000-$e405 (inclusive) to $0300-$0705, resulting in
code from $0300-$075f.
The drive then jumps to $04af.
* $e4b2 speed load the entire track 18 for fast file finding.
* $e4d1 find the file with wild cards.
* $e529 file found, t/s to $b4/$b5
* $e542 print loading
* $e549 check for invalid track. Luxury! smile
* $e55c send track number
* $e566 load entire track.
* $e56d sector out of range for track?
* $e573 load sector data from track buffer until the track changes,
after each loop call $e59c to flush the buffer to memory.
* $e593 file loaded, flush buffer by calling $e59c a last time.
* $e599 exit out, done.
Load entire track at $e725:
* $e725, initialize sector count, set number of sectors to $a3. Start
on sector 0.
* $e742, call $e61f to get one block in two halves from drive to
$fe00/$ff00 and merge it into $e900+sector number using the two 32
byte tables at $e7ab and $e7cb. Checksum to $d7.
* $e748 add interleave 3.
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tlr
Registered: Sep 2003 Posts: 1787 |
Quote: @tlr: Get an AMICA Paint original disk, the loader is used there.
Did this loader ever surface? |
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iAN CooG
Registered: May 2002 Posts: 3186 |
I think I found it, from coll\bugjam\Box103\disk082a.d64+disk082b.d64
https://www.dropbox.com/s/8ccceit14rnnzig/amicapaint.zip?dl=0
the file "MOST-ACCESS C000" in side A is exactly as Most-Access II+ and has nothing to do with 25xturbo, no matches in code. Some more evidence is needed to prove this was by Oliver Stiller, other than "trust me bro" |
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tlr
Registered: Sep 2003 Posts: 1787 |
Quote: I think I found it, from coll\bugjam\Box103\disk082a.d64+disk082b.d64
https://www.dropbox.com/s/8ccceit14rnnzig/amicapaint.zip?dl=0
the file "MOST-ACCESS C000" in side A is exactly as Most-Access II+ and has nothing to do with 25xturbo, no matches in code. Some more evidence is needed to prove this was by Oliver Stiller, other than "trust me bro"
Exactly. The claim that "Most Access II" on an original Amica Paint disk is the BKS Odenwald branded turbo is unsubstantiated as no turbo called "Most Access II" has surfaced so far.
I've seen only "Most Access II+" and this "MOST-ACCESS C000" on the Amica Paint disk, and those variants are completely different.
Good find! |
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chatGPZ
Registered: Dec 2001 Posts: 11352 |
Quote:Some more evidence is needed to prove this was by Oliver Stiller, other than "trust me bro"
I don't quite understand what exactly that refers to - but Amica Paint (and Most Access) is from 64er Sonderheft 'Graphics', pretty sure it mentions who made what. Perhaps later versions were also published in 64er. |
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tlr
Registered: Sep 2003 Posts: 1787 |
Quote: Quote:Some more evidence is needed to prove this was by Oliver Stiller, other than "trust me bro"
I don't quite understand what exactly that refers to - but Amica Paint (and Most Access) is from 64er Sonderheft 'Graphics', pretty sure it mentions who made what. Perhaps later versions were also published in 64er.
This thread is about 25 X Turbo. Graham claims it's by Oliver Stiller in post #7. It may be so, but there's no real evidence of that so far. |
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Oswald
Registered: Apr 2002 Posts: 5086 |
most access was my fave turbo back in the days. |
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Krill
Registered: Apr 2002 Posts: 2969 |
Is it just me or is "Most-Access" one of the worst names ever conceived? =) |
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tlr
Registered: Sep 2003 Posts: 1787 |
Still no sign of the origins of this. I'm still wondering. |
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chatGPZ
Registered: Dec 2001 Posts: 11352 |
Did you check 64er disks? |
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tlr
Registered: Sep 2003 Posts: 1787 |
Quote: Did you check 64er disks?
I think I tried a bit a long time ago but couldn't find a comprehensive collection of them all.
EDIT:
Searched a bit again and eventually found somewhere that Amica Paint was originally published in 64'er Sonderheft 27 (1988).
The disk can be found here: https://www.planetemu.net/rom/commodore-c64-magazines-d64/64-er..
This disk contains the loader MOST-ACCESS C000, which surprise, is very similar to the other MOST-ACCESSes I've seen. It is however completely different to the BKS imported one discussed here so I find Graham's claim dubious. He does claim it's a text edit of MOST-ACCESS II though, so I guess that loader may be available somewhere else? |
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