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Multi-cartridge for Dragon/CoCo 2 available


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:waving: Is anybody is interested in an eprom based multi-cartridge for Dragon 32/64 or CoCo2?


I do not want to double all the information that's already out there, so if you want to know more, please visit:

Dragon multi-cartridge is back! Version 1.6 for sale


New Dragon multi-cartridge version 1.5 for sale

on "The Dragon Archive" - Forum - For Sale

There are a few cartridges left.

Additional information can be found in the corresponding threads of the "Hints and Tips" section.


Best regards,


Edited by Rolo
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Dragon Multi-Cartridge (CoCo 2 compatible):


  • offers 64 8k slots
  • adjacent slots can be "connected" to 16k slots
  • switchable auto-start
  • rom selection by rotary switches and number-display
  • eprom-based (27C4001)
  • for roms running in cartridge-address-space: 0xc000 ... 0xdfff
  • easy to use
  • no cables, no peripherals, no extra power
  • plug-in and just go!
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Dragon/CoCo Multi-Cartridge


I forgot to mention, for those of you, who are interested in a Multi-Cartridge, but who don't have access to an eprom-programmer and don't want to buy one. I'll burn your eprom for you of course.


You compose your roms yourself:

  1. make sure, your roms are cartridge roms and are able to run in cartridge address space ($C000 and above)
  2. make sure, all roms are exact 8k-blocks (8192 bytes)
    -> I simply double 4k roms or quadruple 2k roms for achieving this for small roms
    -> or you pad the unused bytes with the help of some hex editor or tool
  3. make sure, all 16k roms are exactly 16k-blocks (16384 bytes)
  4. order your roms:
    16k roms always start on even banks 0,2,4,6,8 .... 62
    8k roms can be put anywhere
  5. concatenate your roms
    Linux and Mac: cat rom0 rom1 rom2 ... rom63 burnfile.bin
    Windows: type in command-window: copy rom0 + rom1 + rom2 + ... + rom63 burnfile.bin or copy rom* burnfile.bin

burnfile.bin should have an exact file-length of 524288 bytes.


Quite easy! You just email me burnfile.bin. I won't look into it or do something with it, but just burn it onto the eprom of your Multi-Cartridge.







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"Buy your Dragon a Multi-Cartridge" - Easter-Sale 2016


Special occasion (as long as stocks last): :dunce: US$ 27.28 :dunce: only*) !

  • latest version (1.61)
  • 64 x 8k slots (that's only 43 cents for a 8k slot!)
  • 16k-capable
  • switchable auto-start
  • simple to operate

*) plus international shipping (US$ 7)

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  • 1 month later...
:!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!:


Dragon multi-cartridge to Odyssey 2 Extension

I'm presenting something new:

The Dragon multi-cart to Odyssey 2 Extension


Make your multi-cart a multi-multi-cart!


Look at that:

The Dragon multi-cart is playing games on Philips G7200! Cool?


Also on the G7400:


with "PLUS-"graphics:


and "The VOICE" (modified G7400 with voice-module inside. Note: The cartridge slot of my G7400 is only about 3 cm deep. On a regular G7400/G7000 the cartridge would be immersed deeper.)


With the new extension you can use your Dragon/CoCo-multi-cartridge to play your 2k/4k/8k VIDEOPACs on your PHILIPS G7x00/Odyssey 2 systems. One multi-cartridge, two systems! :o

100+ new roms! :thumbsup:

You can mix Dragon roms and VIDEOPACs on the same cartridge as you like, i. e.

slot 0 to 40 Dragon roms

slot 41 to 63 VIDEOPACs and so on.

The best thing: I'm planning to make this available. :lol:

I cannot tell the exact price yet. I'm having problems to get the slot connectors for a cheap price. Only a few companies are selling those any more. The regular price is very high (depending on quantity)!

I'm aiming at a price range of something like US$ 15 or so for a "Videopac-Extension-Cart", but at the moment can't make it, because of component pricing.

I absolutely need to know, if there is any demand for my Videopac-Extension-Carts. Quantity is decisive for the price! If you want one, please post or PM. I'm making a list. First come, first served. Depending on that, I'll make just a few "prototypes" (more expensive) or hopefully can order components for a reasonable price.

Do I have any Dragon Multi-Carts left? Yes, I do have a few sitting on my shelf. I'll be making more, if needed. The project still is alive.

I'm going to post updates from time to time.




Edited by Rolo
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project update:

I've been testing some random 60+ VIDEOPAC-roms:

  • 2k/4k/8K
  • standard and "plus"-versions
  • with "The Voice" and without
  • G7400 only and "universal"
  • PHILIPS/Magnavox, Parker, Imagic, ...
All are running without problems, except VP31 "Musician" :music: (You have to get the original one, including the overlay! :party: ) Maybe I'm just having a bad rom-file.

Looking fine, but I can't guarantee that really ALL Videopac-roms are running.

Still trying to get cheap components. :?
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:cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o :cool: :o

The Dragon/CoCo multi-cartridge is playing "SCRAMBLE" on the VECTREX console!

:!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!:


The Dragon/CoCo multi-cart to Vectrex Extension

Play 4k/8k/16k VECTREX-roms with the Dragon/CoCo multi-cartridge on your Vectrex console. Mix roms for Dragon/CoCo, Odyssey2 and Vectrex in any way you want on one chip. At least 50 new roms for the Dragon multi-cart! A real Multi-cart!

The prototype is ready and running. As you can see, I had to make some corrections on the prototype pcb. And, annoyingly, the Dragon/CoCo multi-cart is upside down. :dunce:

This will change on the production pcb! Don't ask me, why it's upside down. :sleep:

NOTE: To work with the Vectrex, a simple, minor mod is necessary on the Dragon/CoCo multi-carts (version 1.5, version 1.6, version 1.6.1) . I'm showing this at: http://archive.worldofdragon.org/phpBB3/viewtopic.php?f=6&t=5366&start=40#p15024 :idea: Future Dragon/CoCo multi-carts will be modded by me. Dragon/CoCo multi-carts version 1.0 will not work.

Owners of the multi-cart, who don't want to do the mod themselves, are invited to send their carts to me. Modding is free of charge, you just pay shipping both directions. Please attach address sticker on cartridge and PM me.

NOTE: The Dragon/CoCo multi-cart to Vectrex Extension is not a stand-alone storage device. It is just an adaptor-pcb for the Dragon/CoCo multi-cartridge.


Playing a 16k-game


New pcbs will be ordered soon. First production-run will start probably middle of august.

Exact price yet unknown, due to component price problem. I absolutely try to stay below US$20, cheaper if possible. I'll keep you informed.

If you are interested in the Dragon/CoCo multi-cart to Vectrex Extension you can register now, right here or privately via PM. You can withdraw anytime. But please think twice and help me to get my logistics right. :thumbsup:


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project update

  • Going to order the newly designed Vectrex Extension Cartridges pcbs today
  • Waiting for a batch of eproms to arrive ...
  • I think I found affordable connectors. I hope they are no trash. Waiting for them to arrive from the Far East ...
  • Ordered all kinds of components. Waiting for delivery ...
  • Registered a handful of potential customers for Multi-carts and Extension carts.
  • Need to build a few more Multi-carts.
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I still don't have all components. Production has not yet begun.

The Multi-cart (common storage device for all covered systems) is US$29.99 plus shipping.

The Odyssey2-Extension cartridge probably will be something around US$15.

I will keep you up to date, as soon I have made the things.


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project update


collecting components and parts:


building things as far as possible:


Still waiting for some parts, but making good progress. Delivery will start soon. :)


I did a price calculation:

  • The price for the Multi-cart to Videopac Extension will be: US$12.99 (plus shipping)
  • Same price for the Multi-cart to Vectrex Extension: US$12.99 (plus shipping)

- Rolo


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The Dragon/CoCo multi-cart to Vectrex Extension now is available!

I tested the prototype and made a batch of cartridges. Look at the photos:


Extension cartridge and Dragon/CoCo Multi-cartridge:


Plugged into the console. Note the direction of the boards: Always component side up or showing to the front of the console. Do not plug in, in opposite direction!


It's working (playing) ...

Roms up to 16k can be played, with the current Multi-cart.



Price US$12.99 plus shipping!

Register now!


Next step: Reproduction of some Dragon/CoCo Multi-carts...




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Dragon/CoCo Multi-cartridge FAQs

What is a Dragon/CoCo Multi-cart?

The Multi-cart was designed to to hold a variety of Dragon/CoCo rom cartridge based programs, which are running directly from the eprom at address range $c000 to $ff00. The cart holds up to 64 8k-roms. It can play roms with a size of 1k to 16k. You simply select a memory slot from 00 to 63, press RESET on your Dragon, and the program launches. This enables you, to use your Dragon simply without further hardware setup: no cables, no drives, no extra PSUs, no controller-carts.

How about disk or floppy programs?

Do not run unmodified on the Multi-cart. In many cases, a little loader routine can be put in front of the file, which copies the program from eprom to it’s proper ram-address range and launch. Re-loaders are not working this way. Often the first part of the program is just the title screen, which is loaded into video-ram. In this case, this can simply be omitted and the procedure works again.

Why did you make the cartridge?

I was looking for one a few years ago, couldn’t find one, made one myself.

Why are there different versions of the Dragon/CoCo-Multi-cartridge?

I started with version 1.0, using my components in the drawer, learnt some lessons and made version 1.5, realized some improvements and made version 1.6. Then v1.61 and v1.62 with little changes.

Is there a list of tested roms for the Multi-cart?

For Dragon: yes. Please have a look into The Dragon Archive Forums’„Hints and Tips“ section(http://archive.worldofdragon.org/phpBB3/viewtopic.php?f=8&t=3922&start=10#p9517).

Concerning Videopacs, I did not find any non-working standard 1k/2k/4k/8k-roms. Exception Musician, Chess, Basic. So, almost all are running.

Same for Vectrex, but at the moment roms are LIMITED to a maximum size of 16k!

Where do I find the Dragon modified roms?

They are somewhat scattered and hidden in The Dragon Archive Forums’„Uploads“ section, i. e.:

.. .. .. ..

Is there a shell available?

No, I changed the dimensions two times. I am mounting the pcbs on protective metal bottom plates. This is sufficient and fits nicely into the Dragons cartridge port. For people, who absolutely want a shell, I recommend to use recycled ATARI VCS cartridge shells and physically modify them with an electric drilling tool, to adapt them for the Multi-cart.

What are these Extension cartridges?

Simply adapters/interfaces which you plug between your Odyssey2 or Vectrex and the Dragon/CoCo Multi-cart. This enables you to use your Multi-cartridge on different systems, which makes it a quite cost-efficient solution.

Do Extension-cartridges store programs, too?

No. They are only interfaces.

What Extension-cartridges are out there?

At the moment Odyssey2 (Videopac) and Vectrex.

More to come?

Probably yes, but not too many.

Why should I buy a Multi-cart plus an Extension-cart, when I can have dedicated cartridges for all systems?

Buy what ever fits your needs the best. If you already own a Dragon/CoCo Multi-cart, then the Extensions are expanding your possibilities to use your cartridge.

Why do you use eproms instead of a SD-card?

I like eproms: they are cheap, easy to put into applications and easy to operate - and very „retro“. Every retro-fan should have an eprom-burner and an UV-eraser. These are cheap tools (on ebay for example) and can be used for all kinds of old computers. Making SD-card based devices is more complicated and usually makes these devices more expensive. Whereas SD-cards are quite useful on dynamic systems, which are getting new software all the time, eproms are good for older systems with a more or less static and limited software library.

Will you never make an SD-cart-based Multi-cart?

Maybe sometimes. I don’t know.

What programs are initially stored on the Multi-cartridge, when delivered?

None. Since I do not know the legal situation of all those roms and do not know, which licenses you own, I better deliver an empty eprom. Decide yourself, which roms you may copy and which still are legally protected.

How do I get programs on the cartridge?

You need an eprom programmer like the well-known Willem-programmer or any other device. You find plenty of those on ebay. Consider, that some devices need a genuine parallel printer-port, which unfortunately passed into oblivion on modern PCs. So maybe look for an USB-only programmer.

The programmer burns a single, exact 512k-file (512 x 1024 = 524288 bytes) onto the eprom.

You make sure that all program roms are exact 8k or 16k, this means, with the help of an hex-editor you might have to pad zeros at the end of a file. Most roms already have a correct length.

Or multiply small files to get 8k-files, i. e. concatenate a 2k-file four times to get an 8k-file and save it.

How is concatenating done?

On Mac and Linux systems there is a standard shell-command: cat file1.bin file2.bin … filen.bin > result.bin

On Windows there is an ancient DOS-command: copy file1.bin + file2.bin + … + filen.bin result.bin

You simply concatenate exact 8k- or 16k-files until your result.bin is 512k. Take care, that 16k-files are aligned to even 8k-slots.

It’s simple and fast. I’m normally making intermediate files first, consisting of eight 8k-roms (64 kbytes).

I’m doing this eight times and finally concatenate the eight intermediate files to the final binary. This make debugging and changing roms a lot easier.

How do I get rid of programs on my cartridge?

Put your eprom into an UV-eraser box for 15 to 20 minutes.

Can I mix roms of different systems on the same eprom-chip?

Yes, any order you like.

What’s the use of the 8k/16k BANK-SIZE switch?

It combines two adjacent 8k-slots to a 16k-slot. 16k roms must be aligned. Always even-odd, like 2-3 or 10-11…

What happens if the BANKSIZE-switch is in the wrong position?

Position 16k: Small programs, no effect. But you can’t access the odd rom-slots, only even slot-numbers.

Position 8k: Large programs won’t work properly.

How do I remember, if a rom is 8k or 16k?

Write a list, a table of content.

What’s the use of the AUTOSTART-switch?

Dragon/CoCo only: It’s activating/deactivating the autostart feature. For games autostart is fine, but for some development tools memory must be cleared manually before launching.

Which direction do I plug the cartridges in?

All cartridges and extensions are always facing up (components and labels on top) or when plugged in vertically, facing to the front of the console.

What happens if I plug it in, in the wrong direction?

Errrgh, don’t do it.

What happens, if I selected a wrong rom of another system?

No damage.

Dragon/CoCo usually crashes.

Vectrex runs inbuilt MINESTORM, instead of cartridge game.

Odyssey2 does not show „SELECT GAME“, but garbles screen.

Can I mix roms of different systems on the same eprom-chip?

Yes, any order you like.

Do you have plans to cancel the project soon?

No. As long as people are buying cartridges from time to time, I try to always have some parts at home or produce a new version.



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