Posted By
Plus4fan
on 2010-08-12
04:55:46
|  HER turbo & autostart
Hello,
I'm searching for information about HER Turbo. A precise description is required:
1. how HER Turbo handles the autostart?
2. how can be disabled autostart manually?
Please respond to this topic if You know the correct answer.
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Posted By
Chicken
on 2010-08-12
08:25:01
 | Re: HER turbo & autostart
1. Just like any other turbo tape (that does not require some code to be in RAM/ROM). The loader code is "hidden" in the file name, using the tape buffer. Then this loader code is started by overwriting vectors.
2. The actual program is not "autostarted" but the loader code is. And this usually ends with some kind of JMP. If I remember correctly, in HER this is located at $0390. Just JMP to some copy/save routine for best results.
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Posted By
Plus4fan
on 2010-08-12
13:07:29
| Re: HER turbo & autostart
Please specify which vectors are overwritten? Provide as much detail as You can.
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Posted By
MMS
on 2010-08-12
16:15:05
 | Re: HER turbo & autostart
Yes, Sir! Will happen, Sir! :-D
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Posted By
Chicken
on 2010-08-12
16:47:09
| Re: HER turbo & autostart
It's much easier to be specific if you would just tell us what you intend to do.
Do you want to copy a program from a tape? Don't worry about the vectors because you need the loader code anyway (it's the loaded program that you don't want to start).
If you are using an emulator like YAPE, it's a piece of cake. Just LOAD the program. When you see FOUND ... on the screen, go to the YAPE monitor (not TEDMON) right away.
The tape buffer starts at $0332, usually, there's some name and sometimes some empty bytes before the actual loader code starts.
D0390 (or somewhere near) should show some JMP, that's the startaddress of the program. JMP to a copy/save routine instead. Exit the YAPE monitor and loading will continue.
If I remember correctly, the HER turbo "saver" resides in video ram so you don't really have to worry about the location of the loaded program because it won't start below $1000.
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Posted By
Plus4fan
on 2010-08-13
07:11:06
| Re: HER turbo & autostart
Thank You for the information. It was very useful.
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Posted By
Chicken
on 2010-08-13
11:54:36
| Re: HER turbo & autostart
You are welcome 
You could still let us know what you are trying to do. If you retrieved some long lost programs feel free to upload them.
Also, you might want to register. Just write a mail to Csabo and include your desired password. He'll set up an account for you.
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Posted By
Plus4fan
on 2010-08-14
04:48:32
| Re: HER turbo & autostart
The theory of operation of auto starting / auto turbos always interested me, but I never had a chance to understand it (in 1987-1990 period).
Now I have analyzed it:
1. On the initial stage (after load + play) the tape buffer is filled with the:
$333 - load start address: $314, the IRQ vector
$336 - load end address: $336, only 2 Bytes are loaded
$338 - file name (16 Bytes)
$348 - turbo loader code
2. After the 2 Bytes are loaded at $314 ($48 $03), the IRQ calls the loader code at $348.
The 1st stage loader loads the 2nd part of the loader $200. The 1st stage loader calls the 2nd stage loader (jmp $200) at $390.
3. The 2nd stage loader loads the turbo saved program to the final address (> $1000) and starts it with direct jump at $236 (or with JSR to $8xxx if it has to be started with RUN command).
Some HER versions use the $700 area for the stage 2 loader.
This is what I always wanted to know about HER. :)
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Posted By
Csabo
on 2010-08-14
18:54:52
| Re: HER turbo & autostart
I have an idea for an interesting and hopefully useful project. I might do it someday if no-one else does. Anyway, I think it would be cool to test all existing tape turbos. Take some big executable (something like "Mercenary" or "Elite"), and save that file from YAPE to TAP files using all the turbos. Then we can compare their actual loading speed and the resulting TAP file sizes (which I assume would be related - shorter files would mean faster loads, but I'm not 100% sure).
Anyone up for it?
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Posted By
Plus4fan
on 2010-08-15
00:56:55
| Re: HER turbo & autostart
One more HER specific issue:
If I save any file from BASIC with SAVE "filename",7 command, the saved file name is always corrupt. What causes this issue? From monitor it is working properly.
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Posted By
Chicken
on 2010-08-15
10:49:35
| Re: HER turbo & autostart
I haven't tried this but you could check if SAVE"FILENAME",7,1 works properly.
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