| |
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.
|
|
| |
Oswald
Registered: Apr 2002
Posts: 5086 |
wasnt 16x the max ? afaik only warp goes beyond that. |
| |
tlr
Registered: Sep 2003
Posts: 1787 |
I haven't _measured_ the speed of this. It was named 25 x turbo, but it is very fast.
If it's faster than 16x, I guess the coder didn't know about that limit. ;)
Could it be the work of Dietz/Eikemeier/Joppich/Tempelmann?
|
| |
Yodelking
Registered: Apr 2002
Posts: 189 |
I had a 30x turbo that I believe said something like "Imported by Odenwall" or something, can't remember.
(and I don't know if it actually was 30x, but it was fast.)
It's used in our Bugs Bunny demo though.
Bugs Bunny |
| |
Graham
Account closed
Registered: Dec 2002
Posts: 990 |
Slower fast loaders are 6x speed, the average is 10x and the really fast ones are 15x. Without extra hardware it's quite impossible to be any faster.
I guess "25x" is a result of wrong measurements.
|
| |
Yodelking
Registered: Apr 2002
Posts: 189 |
Arghh.. now I clicked on the 25x turbo URL, and saw that it's the same turbo. :)
But it was called 30x turbo on the disk we got it... :) |
| |
Graham
Account closed
Registered: Dec 2002
Posts: 990 |
The "Imported by BKS Odenwald"-loader is just a text-modified "Most Access II" from Oliver Stiller.
|
| |
tlr
Registered: Sep 2003
Posts: 1787 |
Quote: Slower fast loaders are 6x speed, the average is 10x and the really fast ones are 15x. Without extra hardware it's quite impossible to be any faster.
I guess "25x" is a result of wrong measurements.
Or just bragging by someone spreading it. :)
Anyway, I want to know the origin of it...
EDIT: @Graham: Ah! :) Could you add it here? |
| |
Graham
Account closed
Registered: Dec 2002
Posts: 990 |
@tlr: Get an AMICA Paint original disk, the loader is used there. |
| |
tlr
Registered: Sep 2003
Posts: 1787 |
Quote: @tlr: Get an AMICA Paint original disk, the loader is used there.
I found a couple of Most Access II+ downloads which are similar in some ways, but very different in others.
I haven't found an original Amica paint disk yet, does anyone have a link?
Anyway, the ones I found automatically loaded something when started, so I guess Most Access II was not a loader intended for standalone use.
Did someone (BKS?) standalonify (is that a word? :) the BKS version?
|
| |
Graham
Account closed
Registered: Dec 2002
Posts: 990 |
Back in the days loaders were simply ripped out of other productions. Nobody cared where the loader came from since it was not really considered to be part of the demo, it was just a way to keep loading times low. |
... 23 posts hidden. Click here to view all posts....
|
| Previous - 1 | 2 | 3 | 4 - Next |
