INFOCOM adventure series for the DRAGON64

A place to discuss everything Dragon related that doesn't fall into the other categories.
Post Reply
pser1
Posts: 1655
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

INFOCOM adventure series for the DRAGON64

Post by pser1 »

Hello,
I have just ported the Infocom adventure series for the CoCo to the Dragon64 (25 games)
They will not work on machines with only 32K because the games switch to MAP1 (all RAM)
Basically these adventures are started with the DOS command (our BOOT equivalent)
CoCo DOS loads track 34 to RAM $2600 and executes it.
The loaded part consists of a relocator that moves 800 bytes of code to $5000 and then executes it
This relocated code is a loader that reads from Track 00 Sector 01 untill Track 06 Sector 13 decimal and puts it from $1100 till $3000
This part is the engine that is able to work with all the disks of that collection

After unassembling it, I found two parts that needed changes to work properly on the Dragons:
- disc read and write need rewritting from scratch due to hardware differences
- keyboard scan routines need patching for the different wiring of the keyboards

The disk part was 'relatively' easy because I could re-use the mini-DOS that I had programmed for the conversion of the Orchestra90 for the Dragon.
The keyboard part was even simpler, I have converted some CoCo ROMs to Dragon and have done this many times before.

I decided to have a disc that will contain *only* the engine to be loaded and executed for all of the games. The name of the disk is: ENGINE.VDK

If you are a Dragon user that loves adventures, then be ready to play with this 25 titles:

Code: Select all

DISK-NAME     - Game Name, Year
-----------------------------------------------------
BALLYHOO.VDK  - Ballyhoo, 1985
CUTHROTS.VDK  - Cutthroats, 1984
DEADLINE.VDK  - Deadline, 1982
ENCHANTR.VDK  - Enchanter, 1983
HEARTS.VDK    - Plundered Hearts, 1987 
HOLLYWD.VDK   - Hollywood Hijinx, 1986
HTCHHKER.VDK  - Hitchhikers Guide to the Galaxy, 1984
INFIDEL.VDK   - Infidel, 1983
LEATHER.VDK   - Leather Goddesses of Phobos, 1986
LURKINGH.VDK  - The Lurking Horror, 1987
MINIZORK.VDK  - Mini-ZORK, 1988
MOONMIST.VDK  - Moonmist, 1986
PLANETF.VDK   - Planetfall, 1983
SEASTALK.VDK  - Seastalker, 1984
SORCERER.VDK  - Sorcerer, 1984
SPELLBRK.VDK  - Spellbreaker, 1985
STARCRSS.VDK  - Starcross, 1982
STATIONF.VDK  - Stationfall, 1987
SUSPECT.VDK   - Suspect, 1984
SUSPEND.VDK   - Suspended, 1983
WISHBRNG.VDK  - Wishbringer, 1985
WITNESS.VDK   - Witness, 1983
ZORK_I.VDK    - Zork I, 1980
ZORK_II.VDK   - Zork II, 1981
ZORK_III.VDK  - Zork III, 1982
The disks are the original CoCo .DSK files where I have appended the needed bytes to make them the std Dragon disk size.
These discs have NO data visible in the directory (they are CoCo disks) so if you attempt to do a DIR you will get an ?IV ERROR message

The recommended procedure will be:
- For just one drive:
1) Insert ENGINE.VDK and issue LOAD"ENG04V32.BIN"
2) then insert the disc that contains the adventure you want to play with
3) EXEC&H1100
4) in case you want to savegame, then have a clean disk ready for that. The engine asks for disk change as requied
- For twin drives
1) Insert ENGINE.VDK on drive 2 and issue LOAD"2:ENG04V32.BIN"
2) then insert on drive 1 the disc that contains the adventure you want to play with
3) you may insert a clean disc on drive 2 for savegames
4) EXEC&H1100

cheers
pere
Infocom_Adventure_Series_for_Dragon64.zip
(2.09 MiB) Downloaded 447 times
Alastair
Posts: 669
Joined: Fri Jul 18, 2008 11:33 pm

Re: INFOCOM adventure series for the DRAGON64

Post by Alastair »

Pere,
I take my hat off to you. If only I had a Dragon 64.
pser1
Posts: 1655
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: INFOCOM adventure series for the DRAGON64

Post by pser1 »

Alastair wrote:Pere,
I take my hat off to you. If only I had a Dragon 64.
Thanks Alastair,
the original games were made that way ... they use as much RAM as possible, but if you like these
text adventure series, you could use any emulator (XRoar, Mess/Mame) and have a nice time with
everyone of them.
I am putting together manuals, invisiclues and walkthroughs for every adventure to help users to finish
these adventure games. As soon as I have that work completed, I will upload them here.
cheers
pere

Ps. Have a look at the RAM chips on your Dragon32, I have one Dragon32 with half good chips
that after a small hard mod, works properly as a 64K machine.
Alastair
Posts: 669
Joined: Fri Jul 18, 2008 11:33 pm

Re: INFOCOM adventure series for the DRAGON64

Post by Alastair »

pser1 wrote: I am putting together manuals, invisiclues and walkthroughs for every adventure to help users to finish
these adventure games. As soon as I have that work completed, I will upload them here.
Ahem.
There are The Infocom Documentation Project and The Classic Adventures Solution Archive to name but two. There is no need to spend time replicating work that has already been done.
pser1 wrote:Ps. Have a look at the RAM chips on your Dragon32, I have one Dragon32 with half good chips
that after a small hard mod, works properly as a 64K machine.
Sounds interesting. Are the details available on the wiki?
pser1
Posts: 1655
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: INFOCOM adventure series for the DRAGON64

Post by pser1 »

Alastair wrote:
pser1 wrote: I am putting together manuals, invisiclues and walkthroughs for every adventure to help users to finish
these adventure games. As soon as I have that work completed, I will upload them here.
Ahem.
There are The Infocom Documentation Project and The Classic Adventures Solution Archive to name but two. There is no need to spend time replicating work that has already been done.
Hi,
I found them and thought that having a zip with all the info about that game would help users ...
Once we have the chance to play/use a program we tend to put screenshots, scanned documents and manual in the same folder for easy of use
I am just downloading add putting everything related into the folder's game, no extra work to me, I'd do it for me anyway.

have a nice week-end
pere
pser1
Posts: 1655
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: INFOCOM adventure series for the DRAGON64

Post by pser1 »

Alastair wrote: Sounds interesting. Are the details available on the wiki?
Hi Alastair,
the mod I made in my Dragon 32 that has half-good RAM chips, can be found in a preliminary document by R.W.Hall, National Dragon Users Group
entitled "Upgrading Dragon 32s to 64k of RAM" (I am attaching it here)

The part that explains the mods to be done is in point
4. Modifying the Decoder circuitry (Page two)
Here you will find the explanation in case you have 'half-good' RAM chips in your Dragon 32,
and the explanation for the std upgrade changing the RAM chips.

This document contains schematics that show the connections 'before' and 'after' the mods are done. See page 14.
All in all, it implies adding three wires and cutting one trace under the board.

You can find a similar text here (no diagrams)
http://archive.worldofdragon.org/index. ... 4K_Upgrade
In the section "Modifying the Decoder Circuitry" you will find this explanation.

In a thread here in WorldOfDragon, we talked briefly about that and I added two images of the board with the added wires ...
viewtopic.php?f=7&t=3035&hilit=half+good&start=20

Hope it helps
cheers
pere
Dragon_32k_to_64k_Upgrade_Guide.zip
(5.55 MiB) Downloaded 434 times
Alastair
Posts: 669
Joined: Fri Jul 18, 2008 11:33 pm

Re: INFOCOM adventure series for the DRAGON64

Post by Alastair »

Thank you, I will have to study the instructions when I have more time (I really appreciate the diagrams and photograph).
pser1
Posts: 1655
Joined: Sun Mar 25, 2012 7:32 pm
Location: Barcelona (SPAIN)

Re: INFOCOM adventure series for the DRAGON64

Post by pser1 »

Hello,
I have been playing a bit with some of the adventures and don't like the way
they end when you "QUIT" the game ... the program simply loops forcing the user
to power off and on again because most of the time reset does nothing!

In case you have a Tano, it is worst as you have to unplug and plug again the mains!

I have added to the engine code a small routine that will be called instead of looping
eternally and it will do a cold restart.
In case you are in mode 64 columns with the VGA, this new code resets the module
back to 32 columns and no lowercase.
Now the engines are called
ENG05V32.BIN and ENG05V64.BIN

I attach here an VDK with both new engines, you just have to subtitute the old file
ENGINE.VDK by the new ENGINES.VDK (now plural)

cheers
pere
ENGINES.VDK
(180.25 KiB) Downloaded 428 times
Post Reply