AGD converted games: Pack #19

[pser1]

Hello, yet another release of AGD games for the 6809
It contains six games

Code: Select all

- Jumpcollision by Raul Naveros (C)2015			    'Q', 'A', 'O', 'P', ' ', 'T', 'R'
- Mysterious Dimensions by Yerzmyey et al (C)2016	' ', 'A', 'O', 'P', 'M', 'N', 'B'
- Nemo Kay by Aleksander Titov & Zlata (C)2016		'Q', 'A', 'O', 'P', ' ', 'Z', 'X'
- Night Stalker by Aleisha Beesher (C)2018		    'Q', 'A', 'O', 'P', ' ', 'M', 'T'
- Omelettes for Breakfast by Gabriele Amore (C)2017 'Q', 'A', 'O', 'P', ' ', 'Z', 'I'
- the Planet of Death by Mat Recardo (C)2017		  'Q', 'A', 'O', 'P', ' ', '1', '2'

To start each game you will do
- For CoCo simply RUN"SETAGD"
- For Dragon/Tano you should do
- RUN"SETAGD" if your DOS is *not* bigger than 8K
- RUN"SET8K" if it is greater (using CoCo-SDC with my DP50Extended)

When the game intro screen is shown, you will need to press a key to start the game after choosing the desired control mode (if available).

Cheers
Pere Serrat

[pser1]

some screenshots of these games
regards
pere

[pser1]

and yet some more
cheers
pere

[sixxie]

Planet of Death seems quite interesting... but I'm having trouble managing the inventory. I pick things up and it seem to cycle random stuff through it. It's definitely not the behaviour I see in a youtube video of the speccy version!

[pser1]

Planet of Death seems quite interesting... but I'm having trouble managing the inventory. I pick things up and it seem to cycle random stuff through it. It's definitely not the behaviour I see in a youtube video of the speccy version!

Will try it again and play a bit longer. For sure I didn't do anything that far as using itmes via inventory.
Will let you know ...
cheers
pere

[pser1]

Hi Ciaran,
I think I have found the reason for that behaviour ... Not sure we could find a workaround
The engine has code to deal with inventory items showing a window where you can move the
selected item up and down and so selecting the desired item to use.
Unfortunately the game designer decided to forget about that function and did it hardcoding
Z80 assembly instructions on the AGD file. See code below:

Code: Select all

IF KEY UP
    IF L = 0
        LET L 1
        DETECTOBJ
        LET S 0
        ; ASM 205
        ; ASM 224
        ; ASM 123
        PUT X Y T
        LET S 1
        ; ASM 205
        ; ASM 224
        ; ASM 123
        LET S 0
        ; ASM 205
        ; ASM 216
        ; ASM 123
        LET S 2
        ; ASM 205
        ; ASM 224
        ; ASM 123
        LET S 1
        ; ASM 205
        ; ASM 216
        ; ASM 123
        GET OBJ
        LET T OBJ
        LET S 2
        ; ASM 205
        ; ASM 216
        ; ASM 123
        BEEP 90
        LET P 1
    ENDIF
ELSE
    LET L 0
ENDIF

I will 'unsassemble manually these few z80 code lines and will try to search for a similar function on 6809
They seem to be calls to 'not standard (public)' functions inside the Spectrum engine.
Need some time to see if they have a correspondence into the 6809 engine.
Will let you know ...
cheers

[sixxie]

Ah well glad there's a logical explanation! Typical it would be in one that took my fancy

(But on the whole, you're doing a great job - thank you for your efforts!)

[pser1]

Ah well glad there's a logical explanation! Typical it would be in one that took my fancy
(But on the whole, you're doing a great job - thank you for your efforts!)

Thanks Ciaran, you are very kind.
We knew that some games do contain 'customized' ASM calls and so we decided to forget about them and in fact
this has proven to be ok for almost 132 games.
In this case I am lucky enough to be in contact with Allan Turvey who was the one that 'invented' a clever way to
add code to the engine ... Using the bytes of unused letters in the character set ... you might say it is dangerous
but in fact as it applies to the game you are modifying, you should know what parts can be user for this

Now I have the code used and I am going to convert it to 6809 and try to put it inside the same characters where
the designer put it inside the charset. Just need to clarify where should I save the inventory items codes, an array
that should be reserved somewhere ...
Will need more time to solve it, but it is a nice task learning new tricks!
cheers
pere