The SnarkHunter Disks

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The SnarkHunter Disks

Postby Alastair » Fri Aug 27, 2010 11:29 pm

I know SnarkHunter gave the history behind some of the programs on his disks, but that was on the old forum which is no longer available. So if Mr. Hunter, or anyone who remembers, is reading this I have a few questions about "Wings of War" and "White Cliffs of Dover" that appear on ADVEN04B.vdk.

First off, would I be right in saying that the version of "Wings of War" on this disk is a pre-release version of the game? If not, then why is it that the character's name is different to the name in the tape version, and the game talks about a sequel called "The French Connection"?

Then onto "White Cliffs of Dover" is this also a pre-release version, indeed did Salamander Software ever release this game? And finally, what is the proper procedure for running "White Cliffs of Dover"? So far, the only way I have managed to get it to run is by doing the following:

LOAD "CLIFFS"
RUN "UNBOOT.BIN"
EXEC
RUN

The "EXEC" on the third line puts the Dragon in D64 mode, but surely there is a way to run the game while in D32 mode, isn't there?
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Re: The SnarkHunter Disks

Postby snarkhunter » Sat Aug 28, 2010 8:23 am

Unfortunately, I'm unable to address most of your questions... sorry.

As a matter of fact, these are games I got "for free" from the previous owner of my Dragon Data disk drive, purchased second hand circa 1985-86. I only reorganised my collection, which led to a number of ".vdk" files I (much) later made available here.

Because of this, I do not have the slightest idea where some games originate from. As to adventures from "Salamander", I only own the "Dan Diamond trilogy" as tapes. There might have been earlier versions released, then more or less "improved upon" by the publisher.

Sorry about not being able to provide any actual information.

As to the second issue, i.e. running the game while remaining in D32 mode, you might try a PCLEAR1 command, but I cannot guarantee this will work, due to many text adventures written in BASIC being such heavy memory crunchers. Otherwise, your guess was right: you can use "Unboot" or "D-D" to release the memory used by the DOS before running the game.

Fact is: 32 KB only is kind of tight for "heavy" adventure games, and taking 1.5 KB off the overall memory might be asking too much. There used to be a way of embedding the "unboot" code within one executable program. And any BASIC program could easily be turned into pseudo-machine code, which in turn made it possible to generate one single executable that would disable the DOS first, then relocate the program down in RAM, then reset the RAM hooks for the BASIC program, and RUN the latter as a final step: that's just what we did with "The Ket Trilogy", for instance, for it generated the same memory issue.

I don't think you actually need to EXEC anything after RUN-ning UNBOOT: you should just RUN the program since it should already be acknowledged as a BASIC one.

[Edited]
Just tried the above and it did not work: the game crashed with an "OM ERROR" after the title screen was displayed (and PCLEAR1 did not improve anything there), so it seems the game might not work this way. I will try to run it within "T3" to make sure. Will post again about this later.

Best regards,
Lionel
Last edited by snarkhunter on Wed Sep 01, 2010 1:42 pm, edited 5 times in total.
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Re: The SnarkHunter Disks

Postby Alastair » Sat Aug 28, 2010 3:20 pm

Thanks for your answers. So did the previous owner of your Dragon Data disk drive have any association with Salamander?

As you have discovered PCLEAR1 does not clear enough memory. I have even gone so far as to create a cassette image of White Cliffs of Dover, load that with the disk drive emulation switched off, use PCLEAR1 and still there is not enough free memory. Only by putting the Dragon in Dragon 64 mode (which is the reason for using EXEC) is there enough memory for the game.

That was until I rediscovered 'PCLEAR0', as shown in the "Dragon Notebook" http://archive.worldofdragon.org/index. ... n_Notebook, about five minutes ago. Now I can get the tape I created to work in Dragon 32 mode, but the disk version still causes problems - when I try the instructions for 'disk pclear0' RUN stops working, which isn't very helpful.
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Re: The SnarkHunter Disks

Postby snarkhunter » Sat Aug 28, 2010 7:14 pm

Alastair wrote:Thanks for your answers. So did the previous owner of your Dragon Data disk drive have any association with Salamander?

Well, you're welcome... and ain't it the point in being here? That is, trying to help other Dragon enthusiasts, or at least keep in touch with them...

I couldn't tell for sure, but I seriously doubt the former owner of my disk drive ever had any relationship with any Dragon software developer. As far as I can tell, he didn't have any programming skills either. He was a medical student. The reason he was selling his Dragon stuff was to get the money to buy a more trendy Atari 520 ST and gather even more games and software!

Alastair wrote:As you have discovered PCLEAR1 does not clear enough memory. I have even gone so far as to create a cassette image of White Cliffs of Dover, load that with the disk drive emulation switched off, use PCLEAR1 and still there is not enough free memory. Only by putting the Dragon in Dragon 64 mode (which is the reason for using EXEC) is there enough memory for the game.

That was until I rediscovered 'PCLEAR0', as shown in the "Dragon Notebook" http://archive.worldofdragon.org/index. ... n_Notebook, about five minutes ago. Now I can get the tape I created to work in Dragon 32 mode, but the disk version still causes problems - when I try the instructions for 'disk pclear0' RUN stops working, which isn't very helpful.

Thanks for the interesting link. I would have to see whether or not this trick is also listed in "Inside The Dragon". I do believe most of the later Salamander games would use a m/c loader rather than the traditional LOAD/RUN manual scheme, which could have made it possible to include the PCLEAR0 trick as well, without the user ever noticing it. I'm not sure about this, though...

Alastair wrote:Now I can get the tape I created to work in Dragon 32 mode, but the disk version still causes problems - when I try the instructions for 'disk pclear0' RUN stops working, which isn't very helpful.

I guess this is because the RAM hooks used might not be the same in standard and DOS modes... perhaps we should check this vs the Dragon's "lower memory" maps? Anyway, I assume this game was designed to work in "32 KB" mode, so there must be a way.
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Re: The SnarkHunter Disks

Postby snarkhunter » Sat Aug 28, 2010 7:40 pm

... I just checked the game within "T3" and got the very same "?OM ERROR". Even after clearing as much memory as I could using standard commands. And yet I'm almost certain it was designed for the D32 computer (as all Salamander games), which is quite puzzling.

Never having had an original of this game, I cannot tell about the way of loading it. But it definitely looks like you'll have to cope with the "64" mode if you actually want to play! And it's not even the biggest game from Salamander: the file for "The Cricklewood Incident" is over 25 KB, and I did play that game from my original tape... well, kind of played it, if you like! Who would have been crazy enough to actually consider this a game one could play?!!! :lol:

Perhaps someone with a deeper technical knowledge of the machine, like Ciaran or Rolf, will come with a much better explanation than mine!

And sorry about not being able to provide any "better help" there...

Best regards,
Lionel

[Edited]
Just tried again... and it did work this time, but the game does require a PCLEAR0 in "no DOS" mode. So we now have an explanation. This also means there must have been some kind of loader for the game, unless the tape did include some instructions about the required POKE.
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Re: The SnarkHunter Disks

Postby zephyr » Mon Aug 30, 2010 10:45 am

Thanks to Steve Woolham, there is now a far better way to do a PCLEAR0 on the Dragon. The beauty of this method is that it can be used to perform a PCLEAR0 in a BASIC program. 8-)

I have added Steve's method to CLIFFS, trimmed the program down a little to help save some memory, and added EXEC36055 (force garbage collection) to help prevent OS errors. If you save the attached version back to disk, it should allow you to play the game on a Dragon 32 (after running DOSMATE.BIN or UNBOOT.BIN) directly from floppy disk. I haven't tested it with UNBOOT, but it works OK with DOSMATE.

NOTE: I played the modified version of CLIFFS for about 45 minutes. It seemed to work perfectly during the test period, but I can't guarantee that there will be enough memory free to play the game continuously without problems.

EDIT: I managed to squeeze quite a few more running bytes free. I think it's pretty unlikely that CLIFFS3 will have problems with not enough free memory being available.

Regards,
Steve

Code: Select all
0 ' PCLEAR0 FOR THE DRAGON 32/64
1 ' AND TANDY COLOR COMPUTER
2 ' BY STEPHEN J WOOLHAM
3 '
4 POKE188,PEEK(188)-6:POKE183,PEEK(188):PCLEAR1:POKE188,PEEK(188)+6:POKE183,PEEK(188)
Attachments
CLIFFS2.zip
(10.91 KiB) Downloaded 52 times
CLIFFS3.zip
(10.92 KiB) Downloaded 58 times
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Re: The SnarkHunter Disks

Postby rolfmichelsen » Mon Aug 30, 2010 9:17 pm

I'll pitch in since my name was mentioned...

I don't think I have ever played White Cliffs of Dover, but I have definitively played Wings of War and some other Salamander adventures. As far as I recall, these games didn't use a special loader. I have checked the manual for Franklin's Tomb, and that one is loaded and started by a simple CLOAD and RUN sequence. I don't have the original cassettes handy (stowed away in a box far, far away at my parents' place) but having a look at the source code for all of the Salamander adventures that I have reveal both PCLEAR and CLEAR statements, which indicates that no "special" tricks were played to make these games run on a D32. Again, I'm not sure if White Cliffs of Dover where different.

-- Rolf
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Re: The SnarkHunter Disks

Postby zephyr » Mon Aug 30, 2010 9:35 pm

I have also added Steve Woolham's PCLEAR0 routine to Wings of War. With a few slight modifications, this one now works perfectly even with DOS attached. 8-)

EDIT: The attached WINGWAR3 is modified version of the original from Alastair's 'Various Dragon Games' collection. It has been modified in the same way as the pre-release version mentioned above. It would be better to use this for gameplay rather than the modified pre-release version (WINGWAR2) taken from Lionel's ADVEN04B.vdk. Both work perfectly with DOS attached.
Attachments
WINGWAR3.zip
(10.01 KiB) Downloaded 52 times
WINGWAR2.zip
(10.18 KiB) Downloaded 56 times
Last edited by zephyr on Tue Aug 31, 2010 12:27 am, edited 4 times in total.
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Re: The SnarkHunter Disks

Postby Alastair » Mon Aug 30, 2010 10:14 pm

rolfmichelsen wrote:I'll pitch in since my name was mentioned...

I don't think I have ever played White Cliffs of Dover, but I have definitively played Wings of War and some other Salamander adventures. As far as I recall, these games didn't use a special loader. I have checked the manual for Franklin's Tomb, and that one is loaded and started by a simple CLOAD and RUN sequence. I don't have the original cassettes handy (stowed away in a box far, far away at my parents' place) but having a look at the source code for all of the Salamander adventures that I have reveal both PCLEAR and CLEAR statements, which indicates that no "special" tricks were played to make these games run on a D32. Again, I'm not sure if White Cliffs of Dover where different.

-- Rolf

Wings of War is loaded with CLOADM, a CAS image may be found in the zip file I uploaded (see viewtopic.php?f=7&t=271). WHATIS.EXE states that the image contains a machine language program and nothing else, perhaps Salamander compiled the BASIC program before releasing the game? The same could also be true of Fishy Business (also included in the zip).
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Re: The SnarkHunter Disks

Postby Alastair » Mon Aug 30, 2010 10:22 pm

Steve, thanks. I'll have to test your modified versions when I get the time.
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