Issue 55
Free to download magazine dedicated to Commodore computers
Available as PDF, ePUB, MOBI, HTML,
TXT, SEQ and D64 disk image

Nigel Parker
Spell Checking
Peter Badrick
Text, HTML & eBook Conversion
Paul Davis
D64 Disk Image
Al Jackson
PDF Design
Nigel Parker
Email Address
Articles are always wanted for the magazine. Contact us for details. We can’t pay you for your efforts but you are safe in the knowledge that you have passed on details that will interest other Commodore enthusiasts.
All materials in this magazine are the property of Commodore Free unless otherwise stated. All copyrights, trademarks, trade names, internet domain names or other similar rights are acknowledged. No part of this magazine may be reproduced without permission.
The appearance of an advert in the magazine does not necessarily mean that the goods/services advertised are associated with or endorsed by Commodore Free Magazine.
Copyright 2011 Commodore Free Magazine
All Rights Reserved.



Googling a few minutes and looking for inspiration I came across this blog on the BBC website Now playing @6 music, I don’t know much about the site but the blog entry was intriguing and I decided worthy of a news item and then some.

This entry in the blog The Music of Commodore 64s by Anthony Chalmers set me to thinking about all the Commodore music and the great composers, now is it me and my age again or was it that these guys were so good at there craft that the tunes have stood the test of time so well.

Personally I am going for the later option, yes we are all nostalgic and certain tunes or sounds will take you back to when you were a child sat in front of your machine waiting for the nova loader to reach the end and the final de-crunch before the game loads but at the same time these tunes were infectiously good. Playing out the melodies on a keyboard still has the same fascinations for me.

I wont recite the whole blog basically the guy is saying he runs a music label called Robot Elephant he says “we have a compilation for Commodore 64 Music coming out late this year so they thought I might have something good to say on the subject.”

He talks about how the sid chip has only 3 independent sound channels and how each had to be programmed to create music, the deadlines of the games and limited resources of the machine and the skill of the composers.

He has some quotes from Chris Abbot

So how do you feel when you here a Commodore tune, does the music still have the same effect when played on instruments other than the good old commodore 64, how do you feel about bands like PRESS PLAY ON TAPE and there remakes of commodore classics. is it the music that stands out or the SID chip or was it a combination of the two the skill of the programmer/composer the limitations of the machine and the SID chip itself, whatever the theory (and I am sure if you ask 100 people you will get 100 answers) you cant deny that these tunes still stand out today, rather than a CD track spooling some techno beat samples, the commodore tunes were and still are unique and a testament to the men and women who created them

Comments and suggestions are welcome

Just thought it worthy of a section on C= Free

Readers Comments

From: CommodoreServer ID name, Judland
Subject: COMMODORE SERVER D64 image

Greetings, Nigel.

I've been reading your magazine for some time and enjoy it very much. Thank you for your dedication to us Commodore users around the world.

I've recently created an account for myself on the Commodore Server web site (backing up all of my C64 disk images) and have also uploaded the copies I've downloaded of theCommodore Free magazine.

I was wondering if you would allow me to share these D64 disk images with other Commodore Server users. Could Iget your permission to make these images available for others to add to their collections? If so, I'll also upload the other issues I do not have, so there's a complete set for everyone to enjoy.



Thank you for your comments! I am glad you enjoy reading the magazine.

Please feel free to share the Commodore D64 images with everyone on Commodore Server its actually something I have been meaning to do for some time but never got a ROUND –tu- IT



Cottonwood BBS Update

The Cottonwood website, along with the ACUG website, have been offline for an unknown amount of time. I thought everything was running correctly, but apparently it wasn't, and as a result, my account with DynDNS expired. I signed up for a new account; unfortunately, is no longer being offered as a domain for free accounts, so I had to change the web address for my website.

So the new address to the Cottonwood website is

And the new address to the ACUG website is

I can't remember who it was that set up the account to forward from, but if that person is still on this list, if you could set it up to forward to the correct address, I'd appreciate it.

BTW, in the future, if anyone notices that my website is offline, I'd really appreciate an e-mail letting me know. I'd like to prevent this from happening in the future. Thanks!


ImageFX Manual and Installer Available

Kermit Woodall wrote:

As many ImageFX owners from the past few years can tell you the ImageFX manual was out of print and even hard to find used. The manual, although limited to ImageFX 2.0, was a treasure-trove of tutorials and references to ImageFX.

Now, after a massive effort in print-preparation, the ImageFX manual is available again!

The manual now incorporates all ImageFX features from the 2.0 through the 4.5 Studio release in one perfect-bound volume now with over 500 pages.

Lavishly illustrated and packed with tips, tricks, tutorials and more.

Thanks to modern online print-on-demand services you can now order the manual directly from the link below.

ImageFX 4.5 Studio has retained it's low price of $69.95 and now you can order the manual for only $49.95. A whole nickel below it's original price! Yay! A nickel!


Also now available, thanks to the team at BlitterWolf, is a highly useful installer for ImageFX for OS4. This installer makes the formerly delicate process of installing ImageFX on OS4 quite simple. It's free and can be found at:

Prince of Persia for Commodore 64/128 released

A C64 conversion of Prince of Persia has been released, this released version is based on the original Apple II code by Jordan Mechner. The release requires a Commodore 64 or 128 and an EasyFlash cartridge. You can download the cartridge image from


Code Conrad of Onslaught, Samar Productions, Viruz
Mr. SID of HVSC Crew, Megadesigns Incorporated
Music Mr. SID of HVSC Crew, Megadesigns Incorporated
Graphics Mr. SID of HVSC Crew, Megadesigns Incorporated
STE'86 of The Mean Team Twoflower of TRIAD
Help Conrad of Onslaught, Samar Productions, Viruz

Don’t get excited when you see the D64 image you still need to write it to a Cartridge, as shown by the text below when running the D64

Prince of Persia for c64/128 requires an EasyFlash or a 100% EasyFlash compatible cartridge system.

use 'easyprog' to write the pop.crt.01 file to your EasyFlash cartridge.

see for more information.

if you're using vice, make sure you have version 2.2 or later then download the pop.crt file from csdb and use the 'attach cartridge image' option in vice.

[ ]

So as long as you have vice version 2.2 or greater you can attach the CRT and play the game,

Anyway here it is ACTUALLY running in Winvice on a pc, I know a lot of readers will still do not think this exists or is possible.

Special Keys

Run/Stop.......Freeze frame.

Press again for single frame advance. Press any other key to resume play.

Control-R......Ends the game and returns you to the title sequence.

Control-A......Restarts play from the beginning of the current level.

Control-S......Turns off all sound. Press again to turn the sound back on.

Control-M......Turns off the music. Press again to turn the music back on.

Control-G......Saves the current game

Control-L......Resumes the last saved game. (Press during the title sequence.)

Space Bar......Press to see how much time is left.

Notes From The Games Dcoumentation

About the C64 conversion

I can only speculate why this game never received a Commodore 64 version back in its days. I'm sure the declining C64 market in the US and the high technical complexity of the title had something to do with it. However I always felt that it was a missed opportunity and somehow I thought that it just should be done. And sometimes if you want something to happen, you just have to do it yourself.

I want to thank all the people who have helped in the creation of PoP C64 with their support, suggestions and ideas: STE'86, Conrad, Twoflower, Sander, JCB, Enthusi, DeeKay, Jeff, JackAsser, Krill, Skoe, MikeBetz, Celtic, MagerValp, and all the ladies on #c-64!

Making this was a whole lot of fun! - Mr.SID in 2011

Some Commodore history about P.O.P from Games That Weren’t

1996 Unknown

Around the same time that MOOD made a big impression with C64 sceners in 1996/97, Attilla Pohari put together a preview which would get many fanatical game's players excited, including the C64 crowd.

Even though the classic Prince Of Persia was converted to almost every format in existence, the C64 version for some unknown reason was missed out. Sad, because every version that came out was a huge hit. It's unknown actually if the C64 did have an official version in the planning stages, though the non existence of a C64 conversion was about to be rectified.

A series of stills were released as a slide-show preview, showing various screens of the game on the C64. It was just impressive to see the game making some kind of form on our beloved breadbin, but behind the hype it seems that Prince Of Persia looked a little off colour and plain with its shades of cyan and blue. And even though a lot of screens were in the preview, there was no main character to look at, or any action whatsoever... just some stills and a good conversion of the game's Arabian tune.

Once the excitement died down, so did any sign of more news of the game. The guy behind the graphics contacted GTW and mentioned that the game hasn't been scrapped, but no more has been heard and it seems as P.O.P has finally been stopped.

It is not known how far the game ever reached, and even if the main character was present and running around, just like the original game. Hopefully contact with Viktor will help us find out some more, and even see some glimpses of what had been done.

But as another hunt.. does anyone know if Domark planned a C64 conversion too?... I mean, a conversion on the Sam Coupe as-well, and no C64 version??.. crazy :)

The princess has probably gotten bored waiting for a prince in this C64 conversion...


SID Symphony II Cartridges now available

----- Original Message -----
From: Vanessa Ezekowitz
To: Commodore Free
Subject: SID Symphony II Cartridges now available


The "SID Symphony II" cartridge is now available, and can be found on the Digital Audio Concepts website ( ), along with the internal stereo SID board and my prototyping cartridge board.

The SID Symphony II can be mapped into any 32-byte slot from $DE00 to $DFE0, and should be work fine alongside most other hardware expansions. Works with all stereo-aware software that can address a SID in the above range. It is possible to add a jumper to the cartridge to pick up other page address signals inside the computer (such as $D7xx in the C128).

Each board features an access LED, reset button, and a proper 12v DC-to-DC converter for use with the good old 6581 SID chip. Each board comes preset for $DE00, which can be changed by flipping one or more DIP switches. The audio-in line is grounded by default to reduce background noise, which one can undo by simply cutting a jumper pad.

The SID Symphony II is supplied without a SID chip, and is designed to fit into standard Commodore-issue case shells and their clones.

$39.95 each, plus shipping

This is a limited edition run, so as the old trope goes, "Hurry, while supplies last!" :-)

"There are some things in life worth obsessing over. Most things aren't, and when you learn that, life improves."

Vanessa Ezekowitz

Other Products On The Website Include …

Prototyping Cartridge $7.95

If none of the other products on this page suit your needs, maybe you'd like to build your own cartridges instead? For that purpose, we created this simple prototyping board. Holes are on a 0.1" grid, with power rails down the left side. This board also sports a 9/13/25 pin D-Sub connector footprint at the back end, and is sized to fit standard Commodore cartridge shells and their clones.

SID Symphony II Cartridge $39.95

If you'd rather not open your C64 or 128, and have an expansion port free, we also offer an external cartridge option: The SID Symphony II. Designed to be as simple to use as possible, this cartridge is built for a 6581 SID, and works with any software that can access a SID chip anywhere in the $DE00 to $DFE0 address range (the address can be changed by moving a few simple DIP switches). Sized to fit standard Commodore 64/128 case shells (such as those sold by Protovision or Vesalia Online).

DigiMAX Card Available for Pre-order! Price: $29.95

If the beautiful analogue sound of the SID chip isn't suitable, maybe it's time to go digital instead? For this, we've created the DigiMAX. When plugged into your User Port, it provides four 8-bit digital sound channels (in stereo) through a separate output on the card. With appropriate cables and mixer (not included), one can even use the SID and DigiMAX together.

8BSS Card Available for Pre-order! Price: $29.95

Maybe you would rather record sounds into your Commodore 64 or 128 and process them in some way (or just play them back). In that case, the 8BSS is right up your alley. It supplies two 8-bit analogue input channels, taken through a stereo 1/8" "miniplug" on the card. This device is best used with a slightly amplified source such as a CD player or radio.

Bit Fox For The Commodore Plus/4

Roepipi has created a new game for the Commodore Plus/4. Although the game has been written using the Commodore’s BASIC language it runs quite quickly.

Can you beat this colouring game? It will take about 10 minutes to play the game. Roepipi has also released notes about the game and some of the variables used see text below.

Scope Variable
cycle A$: pressed key
draw B: block code (96: border, 250: path)
cycle C: coloured blocks count / count while drawing
end C$: entered name
cycle D: direction (0=undecided) / title loop counter (1-6, 7:game init, 8:high scores)
prg D(0-3): direction deltas for drawing paths (1,40,-1,-40)
game D$: down key
E: enough of new path (-random)
cycle F: frequency of new path appearing (+: wait, 0:trigger, -:draw)
cycle G: gamer poke
stage H: colour code of coloured block / music state at title (1-92) / high score position at enter high scores
prg H(1-10): high scores
prg H$(1-10): high score names
cycle I,J,K: loop variables
stage L: length of path (1-250, resets at every stage) / sound length at title
game L$: left key
cycle M: move of gamer (direction)
stage O: goal # of coloured blocks
cycle P: will poke at / P%() index while D=0
stage P%(1-250): poke address of block
game R$: right key
game S: stage (1-9) / sound pitch at title
stage T: time left
game U: ultimate score (sum of remaining times + coloured blocks + stage bonuses)
game U$: up key
prg V: sound volume
cycle W: will of gamer (direction) / dummy for some tricks
prg Z: zone diff between colour map and char map (1024)
prg Z$: timer reset string ("000000")

0 program init --> title screen
10 game init
20 next stage init
100 randomize and draw paths
200 control gamer --> out of time OR stage win OR other commands OR randomize and draw paths
250 out of time (game over) --> enter high scores OR next stage init
300 other commands --> next stage init OR control gamer
350 stage win --> next stage init OR game win
390 game win --> enter high scores
400 overall score display - RETURN
500 draw stage - RETURN
900 draw path (returns C=0) - RETURN
990 stage data lines (seed, start, count, direction, ..., count, direction, 0)
1000 title screen
1100 title loop --> game init OR high scores
1120 music loop - RETURN
1170 keys & volume control - RETURN
1300 enter high scores --> high scores
1500 high scores --> title screen
2000 music data (sound 1 pitch, sound 1 length, sound 2 pitch, sound 2 length, ..., -1)

NST's Audio Extension V2.0

A new audio cartridge for the Plus/4 will soon be available. The first batch are currently being assembled. You can read more about the cartridge in the comprehensive manual (English or Hungarian).


Dunjon Battler Released

Recently released is Dunjon Battler.

This release sees our hero battling out in a dungeon against various monsters, where you collect treasure for health and keys to unlock doors. Our hero fights his way through a maze of corridors, and is apparently the first Machine code game the creator has produced. If this is the first them the next will surely be amazing, this is a quality release and reviewed later in this very issue of Commodore Free, for more information (as well as the download PRG file) is available from here

Commodore Is Awesome Forum

Want to talk about Commodore systems, with other Commodore people? Here is a forum to vent out your frustrations, what machine is best, who wrote the best game, who’s machine is the nicest colour who loves you and who needs your support.

Edge Grinder Download

The final version of Edge grinder is available to download from here (the game was reviewed a couple of issues ago in Commodore Free)

Click on Edge Grinder text to download the disk image, this version just adds a loading picture and some loading music .

You may also like to know that another batch of the cartridges has been manufactured and are released for sale in RGCD shop, head here to find out how to purchase the game on a real cartridge

Red Wizard Island For The Amiga

Red Wizard Island is a game for AGA Amiga systems

In the game, you assume the role of a red wizard that has been summoned by the king. Your first challenge will be to get off the island, and there are Vikings are guarding the shores.

For more information and to download the program as a LHA archive head here

There is also a video of the program, for you to watch and an option to donate to the program

Swords Plus/4 Found

An unknown game was recently discovered for the Commodore C16 or Plus/4. Swords is a cool arcade adventure game, which seems to be inspired by Robo Knight. In the game You need to find your way through a manor, you must find the lost swords and the secret chamber full of gold. The game was made by Attila Kardos in 1988 Reviewed later in this issue..

Release Date: 1988-08-16
Language: English
Size: 16K
Machine: PAL Only
Code Type: Machine code
Distribution: Freeware?
Released by: Chip Software Ltd. (CSL)
Created by: K., Attila

Takeover - VIC20

Takeover is a game for the Commodore VIC-20 made by Orion70. The game is a conversion of the C64 version made by Humphrey Walwyn in 1984. In this strategy game you must try to take over the government. You must defeat the evil president Xerxes by taking over as many buildings as you can. To play the game you need a VIC-20 with 16 kByte extra RAM or an emulator

You can find out more by clicking on this link, where you will be transported to a denial forum about the game and its development.

Commodore Games Walk-Through

Ever wondered how your favourite game ended but lacked the skill to progress any further, did you start a game and were to lazy to play it but wondered what happened after the first level? Well help is at hand. Why not watch someone else complete the game for you by just clicking on a link to a video, then grab a cuppa and sit back and relax. You will need to remember to video yourself jiggling the joystick and you can pretend you finished the game and show off to the envy of your friends. (bit sad really you should go and get a real life, anyway its interesting to see how some of these games ended)

Micro-SD Card Drive For Commodore PET

Wow, a micro-SD card drive for Commodore PET computers! PETdisk is now on the market in kit form for $25 (not including shipping). PETdisk is made of two components, the primary board attaching to the IEEE-488 port on the PET and the secondary board attaching to the cassette port of the PET.

To read up on the PETdisk description, see videos on PETdisk, brush up on the user instructions, and peruse the assembly instructions, go to

To read a brief discussion about the PETdisk, go to

Received mine today,

Robert Bernardo

Fresno Commodore User Group

The PETdisk developer says "other users [report] that the PETdisk works on C64 and 128 with an IEEE-488 cartridge interface".

Fairy Well Preview Released

Fairy Well Preview created by Wide Pixel Games (the development group behind the C64 classic Knight ’n’ Grail), is available in a trained version. The game is part of the 16KB C64 Cart Development Competition by RGCD ( ).

To try the game and get a feel of the quality of the development go here:

Review: Dunjon Battler

By Commodore Free

Destroy monsters with your sword, collect treasure chests for health find the hidden chalice to win the game.

Sounds easy lets have a bash then.

The title screen is functional with what some would call Classic SID music, no techno or drum n bass here just a rather weird bleepy click tune, quirky it maybe but it fits the program rather well.

So arming myself with a joystick plugged into port 2 I hit the fire button and am transported into a mystical world of monsters and dungeons, or the same world as I am currently in but starting a computer game sat in front of a TV. Hmmmmm sounded better before.

OK so. Transported to a mystical magical world of wonder and mystery fuelled with monsters, dungeons .

We now see our hero in a room with some flickering lights over an exit or for the more technically minded “a door” with what look like blocks scattered around the room, the blocks don’t seem to be of any use; other than to form blockades or area you have to walk around. The joystick moves our hero and fire causes him to use his sword in the direction he is travelling, quite amusing walking down and using the sword. Everything is functional rather than flashy or showy, still some really good games have had minimal graphics, and this can be overlooked if the game play is good enough.

Movement is well handled and it’s easy to navigate to the exits, one thing I find frustrating is when you exit a room then have to re enter it all the monsters re appear, this seems to be a common bug bear of mine, as you spend the time negotiation the beasts to get to the exit only for them to reappear as you re enter the room.

While the whole program may look like it was written back in the 80`s this doesn’t really detract from its addictiveness, actually I think this gives the whole thing a quaint looking retro-ness or old skool feeling.

Moving around you will soon find treasure that ads to our heroes health

Notice the small treasure boxes now in an open state after being ransacked by our hero

And of course you need to find keys to open doors

The keys are not coloured or coded as you seem to need to open one door to find the next key to open a door etc.

And of course when you have a key you need to find a relevant lock to put the key into

The perspective is a little strange as you are looking down on things but the enemies and our hero then look like they are lying flat on the floor as opposed to sign a head and shoulders, game play is good and the degree of hardness and progressions seem to be well handled by the programmer.

Everything looks a little grey although later levels change the colour and of course you will soon find dark rooms to hunt around for items in.

Sounds are minimal

Graphics: 5/10
Gameplay: 6/10
Longevity: 6/10
Sounds: 3/10

Overall: 6/10

Good effort for a first time venture into machine code programming.

Review: Swords

C16 / Plus/4 Game

By Commodore Free

Deemed to be lost and now recovered and all released or not released in 1988

The idea of the game is to collect all the 12 swords before the timer reaches the zero. Several attempts are needed because any collected sword opens a certain door, which in turn allows you to proceed in the mission. Because of this, a careful track of planning must be followed and mapped. When the last sword has been collected, the door of the gold room appears, located exactly where you started your quest.

(so you slog away for hours only to return back to the beginning)

The game loads and displays a screen with credits

With a joystick in port 2 pressing fire loads to see our hero in a dungeon of some sorts

Moving backward gains us a sword; bit of a tip as our guy is pointing forward you would assume you need to go this way, to collect the sword press down. The torches on the walls flicker to give the illusion of some sort of realism however they do not affect the lighting in the game in anyway. Our guy can move behind some scenery. It looks like it’s a nice game


Movement is slow and very flickery, pressing fire causes our guy to jump but with very heavy gravity I presume this is to point to the fact he is in a suit of armour and so his weight is affected. The screen flick scrolls whichever direction you move in left/right and then things get difficult

Gaps in the floor of the dungeon will need to be jumped, as you weigh some considerable tonnage you soon find jumping is an art form in itself, you edge up to the hole as much as possible and launch yourself with the aid of the fire button hoping to clear the hole.

Now the two small holes themselves don’t pose to much of a problem and you continue deeper in the the dungeon looking around for more swords. The timer ticks on and suddenly !

You reach a hole to big to actually jump, although there is a sword on the other side!

This is where the games skill comes in, collecting swords opens doors and going through theses doors is the key to completing the game, as you will be moved to other areas and hence bypass large holes in the ground.

At the end of the game the massages flashes on screen


And a large pile of gold sits waiting for you to collect, and of curse Gold is the Kings best friend.

Graphics: 4/10
Gameplay: 4/10
Longevity: 4/10

Overall: 4/10

Its frustrating to play, mainly because it’s so very slow to move around.

Interview With Tokra

Creator of VDC-IHFLI

By Commodore Free

Q. Please introduce yourself to our readers

Hi, I'm Torsten Kracke aka tokra from Germany. About 18 months ago, my interest in Commodore machines was rekindled and I've since been active in the usual forums. Together with lots of help from Mike (from the VIC-20 Denial forum) I've released a VIC-20 demo called "Yes VIC can" at the Revision Easter Party this year.

Q. Can you give some of your computing history and how you came across Commodore machines

About Christmas '78 or '79 our family got the first Pong-videogame, which in the later years I upgraded to an Intellivision, and then to a VIC-20 and finally a Commodore 128 before succumbing to the PC. I did a little programming on the Commodores; but just in BASIC, later took my first steps in Assembler and even released a C128-VDC disk to the Public Domain back in 1993 - which you can still find around the net, or on my page now

Q. Can you explain how you came up with the VDC-IHFLI display format?

I was always interested in maxing out the graphic abilities of my Commodore machines as you can see by the VIC-20 demo! There was a commercial piece of software available for the C128 called "Graphic Booster" from a German company way back then. Graphic booster promised resolutions of 720x700 and 65000 colours from the machine, However this was always way too expensive for me. Grabbing all the information I had from magazines and books, I finally managed to program my own BASIC-extension for the 720x700 resolution; and a few month later; I wrote a program for GEOS128 which can display a full GeoPaint-file in a resolution of 640x720. This was as far as I could get back then! Fast forward to 2010 when I found the amazing "Risen from Oblivion" demo for the VDC ; and discussions on the newsgroup comp.sys.cbm about high resolution graphic-modes on the VDC in colour.

Q. What are the technical details for example the Screen resolution

The resolution used in VDC-IHFLI is 640x480 - colour resolution is 2 colours per 8x2 block and the vertical frequency is close to 60 Hz. 640x480 is a standard VGA-resolution which in itself is close to NTSC. I'm not too sure of the technical background here, but you will notice 640x480 in 60Hz is a pretty common resolution. Also, the maximum colour resolution the VDC will display without any tricks is 2 colours per 8x2 block. In 640x480 the bitmap uses 38400 bytes and the colour information uses 19200 bytes, for a total of 57600 bytes which still fits within the 64K of VDC-memory. This also shows why you need an expanded VDC-memory. Older C128-models only have 16K VDC-memory. You can see now that high resolutions cannot be achieved with that amount of memory. Luckily VDC-memory-upgrade kits are still available on eBay - just pull out the VDC from the socket, plug in the RAM-board, and re-seat the VDC. No soldering required.

Commodore Free Editor notes on VDC upgrades:

At the time of writing you could obtain a VDc Upgrade from here

You will need of course to open your machine and plug the device in, full instructions are given the whole thing takes about 15 minutes to fit, I have purchased 2 of these myself from the seller. The units are new and I presume currently manufactured.

Q. And in layman’s terms then how is the image displayed on screen

The VDC-chip produces the full picture. The VDC Is a very flexible chip, if you know how to set its 37 (or 38) registers. Basically you just need to set the registers so that the VDC will display interlace-mode and the resolution you want it to display. Then it depends on the capabilities of your display device if you can see the results.

Sadly, the VDC-chip hasn't been that well documented, but the C128 Programmer's Reference Guide is a great first help, as well as examining other peoples programs. Also very helpful was Richard42 of the who with an oscilloscope was able to provide me with frequency measurements.

Q. So you still have to interlace or swap two screen very quickly to give the effect of a higher resolution, how then is the colour pallet created, and as you say the 64k VDC is need to hold both images in memory at once is this the case

Contrary to the C64's VIC-chip where interlace is done by software the interlace-effect on the C128's VDC is a hardware-capability of chip itself! The colour palettes are just the usual 16 CGA colours the C128 has in this mode. The illusion of more colours just comes through the interlace effect and because the pixels are so close together. That is also how the aforementioned Graphic Booster produces its "65000" colours - in reality its still just 16 colours, just the eyes are fooled by patterns of different colour pixels.

Q. Can you tell our readers how the demo images were they created, you took a jpg or bitmap and then what?

The mode itself would be pretty useless without good images to show for it and as with the VIC-20 demo Mike came through here again. He wrote a converter for my VIC-20-graphics-mode back then, and he also made another converter for his VFLI-mod to the VIC-20 (a small hardware modification which increases the VIC-20's graphic capabilities considerably). When I came up with the C128 VDC-graphic modes the converters could be adapted to fit my mode's needs. While the graphic-mode itself would have been possible back in 1985, the conversion of a picture takes about 2-3 minutes on a modern PC, you can only imagine how long a conversion would have taken back then - and that is IF you had true colour-pictures in a digital format available to convert at all.

Q. How long did the VDC process take to perfect?

It's never perfect ;-) I took probably a week of long nights to wiggle out the VDC's quirkiness to produce a good picture. Talking and discussing this on the really helped a lot, as other people could try different setting and see if they got the same results and their screens and so on.

Q. Do you think the process could be used for anything else other than static images, for example could some the process be uses to create sort of animation, or even demo or is the processing time to much for the machine?

Unfortunately, the VDC chip is pretty much disconnected from the rest of the C128's memory and can only be accessed through 2 bytes in memory, which makes it pretty slow. The VDC itself does have a block-copy routine, which may be able to speed things up a bit, but apart from the "Risen from Oblivion" demo I haven't really seen any impressive quick movements on the VDC - this would definitely be a challenge.

Q. Could the processing time be extended using some sort of accelerator card like the SCPU, or is the graphics chip still to slow to display moving images on the hardware?

An accelerator card would not speed up the VDC chip! in fact the VDC chip is accessed by the C128-kernal, it has to wait for the VDC to signal its readiness and only then will it be able to accept settings to its registers. So I don't think much can be done to speed things up, at least not in a way that would be worthwhile.

Q. So What hardware currently is the system working on currently

You will need a C128 with expanded 64K VDC-memory. Newer C128s already have this. Older ones can be easily upgraded as mentioned before. Then you will need a display device that can display the RGBI-signal of the C128 as well as display the frequency required. Because the picture is 640x480 and 60 Hz and as such close to NTSC should make it work on TV-screens - there are simple RGBI to SCART adapters available for example for European TVs, however most of these will only display 8 out of the 16 colours. The best option is a good old Commodore 1901 monitor, which was the original monitor intended for the C128. However these are hard to come by. In the US this should be the 1902. I've also tested the program successfully on the 1084, but a small fix is needed here for the picture to be centred correctly. Nothing too major.

Q. I guess its a try it and see if it works process, if our reader has a setup that the process works or doesn’t work on is it worth them contacting you to describe the setup of there systems?

By all means! I'm very interested to make the mode as compatible as possible, and while there are certain technical limitations of some display devices that may prevent them from working with this mode, it's always nice to know if a certain monitor has been successfully proven to work or could be made to work.

Q. Why is there a specific setup needed for the effect to work?

The VDC-chip can produce a wide range of frequencies and resolutions. For example both the US and European C128s use the same VDC-chip. The C128-kernal checks on startup what kind of VIC-chip you have (PAL or NTSC) and sets up the VDC registers accordingly, so that it displays either PAL or NTSC. While I've tried to keep my graphic-mode as close to NTSC as possible there are lots of other modes (like 720x700) who bend the frequencies even more, and for this you will need a monitor that can display higher and lower frequencies (often you have to turn a knob called V-Sync). For higher resolutions you will also sometimes have to vertically compress the image (with a knob called V-Size). Sometimes these knobs are only to be found on the back of the monitor and can be labelled differently.

Q. If the images does not show, could our reader contact you with his/her setup for you to investigate

Certainly, yes. Or even better post your question to the, so others may benefit as well if a solution can be found.

Q. Does the process work on both Pal and NTSC systems

The VDC-IHFLI mode is close to NTSC. I have done some experiments with a VDC-ITFLI-mode which is 640x576 with 8x3 colour blocks and 50 Hz, which would be close to PAL. But as said before the VDC-chip itself is neither PAL nor NTSC, it all depends on what you tell it to display and if the display-device you connect can handle the signal.

Q. Do you have any other projects you are working on

Apart from the VDC-ITFLI-mode I've also hacked together a small picture-converter for my old 720x700 monochrome mode and completed some experiments on a non-interlace 640x400 mode for which Mike also provided a converter. Those last two modes I've only been able to display on the 1901-monitor, as both are way off the NTSC or PAL-standards. Then there’s the already released VDC-FLI mode in 480x252 with 8x1 colour blocks which uses a trick I learnt from "Risen from Oblivion" to get this colour-resolution to display. Since the release of that mode, Mike has improved on his picture-converter so that it uses 2D-Floyd-Steinberg-dithering instead of 1D-dithering, giving much better results.

Some day soon I hope to be able to put these all these modes together; in a yet to be named VDC-package. I'd like to get more feedback first on the existing modes and do some more tests with a new display connector by Richard42, that connects the C128 VDC to a VGA-monitor before release.

Q. Do you intend to document the process for other coders to use this format?

The process was discussed in the - also the source-code itself is pretty small (screen size) and should hopefully be easy enough to understand. Otherwise the forum is always a nice place to get help and discuss ideas.

Q. Will you be tweaking the format to make it more compatible/efficient?

Of course, but I rely on user-feedback for this. I've already completed some tweaks like being able to centre the picture with the cursor keys. Before a widespread release I'd like to perfect this some more, so please get in contact with me - my contact information is in the readme.txt of the VDC-IHFLI release.

Q. So where will it all end then, we have a format that the machine isn’t capable of displaying, and I have heard 6 channel and more sounds on the SID, mixed down to 3 obviously, so what’s next.

The good thing about the Commodore 128 and even the VIC-20 is that those machines still have some secrets to be discovered and it's a lot easier to still find them than with the C64 because the machine has a lot more people trying (sometimes successfully) to pry the last secrets from it.

Q. Do you feel there is a challenge to constantly obtain more from the machine?

I think that is what retro-coding is all about:

Show that your old machine still has some tricks up its sleeve. Having this "WOW - I can't believe this is running on a [insert your favourite old computer here]"-effect is priceless.

Q. Do you have any other comments you would like to add

Don't underestimate the Commodores besides the all-mighty C64. And if you're just a user and don't know why something won't work, don't be shy to ask about it in the forums or contact the author directly. Most of us love the feedback, I know I do!

Review: Bit-Fox

By Commodore Free

You are a painter locked in a scientific world of squares, your job “should you wish to accept it” is assigned and ready for you to take. “Paint all the squares” you decide to accept the job and don’t even flinch when you are given a time limit to paint all the squares in each level. After all you think a job is a job, and how can you turn down work, especially in a recession.

Load Em Up

Loading the game gives a very basic title screen where we can adjust the volume, start the game or check the highscores. Checking the scores gives a feel for the game; as they slowly flick up the screen, this game is written in BASIC isn’t it!

Well yes it is.

Moving the cursor or joystick left or right turns the sound up or down.

On Your Marks Get Set……

Starting the game by pressing the joystick up or the up cursor key takes us to what will be a familiar level style territory.

We have a number of squares that need colouring, as you start to colour these, by moving over them , as you move over a square its automatically coloured in. Then and at a random time frame; more squares will appear, these are random in number and random in location but form some sort of pattern as they only appear in straight lines of X amount of squares. The idea of the game is simple; to paint all the squares before the timer runs out. If the timer runs out you will be given an amount of points but of course not as much as if they were all coloured in.

Good Idea

To be fair the idea is great! although I seem to remember something similar; but can recall its name. I know there are various painter style games where you draw out an area of the screen and then its coloured in KWIX is one that springs to mind although this is a totally different game.

The games main problem; is the facts the whole thing is written in BASIC, although its seems quick at the start (apart from the highscore display) the game soon slows as you are moving and its drawing blocks, also sometimes the joystick and keyboard don’t seem to be recognised and you are lurching and hitting keys wanting them to have an effect. Again down to Basic being so slow.

Its best to, start to move and you continue to travel in that direction, then press up or down “before” you need to; something like 2 squares in advance, of course if you need to go up at the next square you could have a problem.

Sound is some blips on the title screen, acting as a music composition and in game sounds are again blips, to be fair the game doesn’t need much. This could be a good game but it needs a rewrite possibly in Machine code. Graphics are fine for what the game is. Although I would have loved to have seen something like a creature appearing and randomly turning 1 square beck so it would need painting again.; Or a square randomly turning back from its painted state.

Graphics: 1/10
Sound: 1/10
Gameplay: 5/10
Lastability: 3/10

Overall: 4/10

Excellent idea, although a speed boost is needed, with the joystick and cursor keys sometimes not being recognised but that’s mainly is the fault of BASIC being so slow.