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Thread: Creative Music System / Game Blaster clone

  1. #1
    Join Date
    Jun 2017
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    Default Creative Music System / Game Blaster clone

    Greetings,

    I have been interested in the Creative CMS or Game Blaster cards for quite some time but since the cards are fairly rare I haven't been able to obtain one. I stumbled across the work by Tronix described here and saw that he had some success at building a clone of the CMS card.

    Tronix had problems with a large amount of noise making it into the output of his card but this was likely due to the lack of a good ground plane and separation of the audio from the digital signals.

    Since I haven't been able to find an actual CMS card I decided to build my own based on the work by Tronix and the Sergey's auto detection circuit. In the end, I modified Sergey's auto detection circuit because it allowed the card to respond to addresses that it really shouldn't respond to. While I was at it, I added a jumper to set the card's IO address anywhere from 210 through 260 like the original creative card.

    I decided to use the same TEA2025 amplifier that Creative used on the Game Blaster cards. Based on the pictures of the card that I was able to find, it looks like the amplifier on Creative's card is very similar to the reference example in the TEA2025 datasheet so I used the capacitor values from the datasheet.

    The result is what I hope is an accurate sounding clone that should have nearly 100% compatibility with the CMS / Game Blaster. Due to the problems that Tronix experienced, I decided to go straight to a 2 layer PCB design and tried to keep the analog signals as far as possible from the digital lines.

    I got my prototype PCBs back from the fab last week and built one of them this weekend. The card is detected by the Creative testcard utility and the audio output appears to be quite good. There is a little bit of background noise in the output when the card is not playing but it is not objectionable. In fact the noise level is about the same as the background noise level of the Sound Blaster 16 that I have in the same system.

    REVA.jpg

    One problem I encountered was I didn't have a 10k dual audio taper pot that was short enough to fit through the bracket once the card is installed in an ISA slot. So, I soldered 4 resistors in it's place to create a fixed output that is somewhere around line level. It looks a bit odd because the PCB footprint is for a pot but it works!

    I think I may actually leave it that way because that way I can run the output of my clone card into the line in of another audio card to have both CMS and Sound Blaster support in the same system coming out the same set of speakers. I currently have my card set to address 220 and a SB 16 set to address 240 which appears to work fairly well.

    I don't have a real CMS or Game Blaster card to compare to so I don't know how accurate the sound output is but it sounds pretty good to me.

    Here are some quick recordings I made:


    Compatibility appears to be very good. So far the card has worked in everything I have tried including Bubble Bobble which I understand doesn't normally work when using a Sound Blaster with the CMS chips.

    The board layout and Eagle project files for my prototype is available here if anyone is interested.

  2. #2
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    Great project, and thanks for making the files and layout available!
    Offering a bounty for:
    - Documentation and original distribution disks for: Panasonic Sr. Partner, Corona PPC-400, Zenith Z-160 series
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)
    - Any very old/ugly IBM joystick (such as the Franklin JS-123)

  3. #3
    Join Date
    Jun 2017
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    Virginia, USA
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    Quote Originally Posted by Trixter View Post
    Great project, and thanks for making the files and layout available!
    No problem, I think it is important to make things like this available so that the hardware can live on in one form or another.

    Be warned, I am not an electronics expert by any means - just a hobbyist and I am sure my project files and PCB design reflect that. I am just pleased that the card actually works and so far I haven't found any major problems with it.

  4. #4
    Join Date
    Dec 2014
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    The Netherlands
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    I take it you had to order a certain minimum number of PCBs?
    In which case, are you interested in selling a few to people such as myself, who may want to build their own clone (I already built the Lo-Tech Tandy card)?
    Alternatively, I'd also be interested in one if you assemble it yourself.

  5. #5

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    Looks great! I updated Wikipedia.

  6. #6
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    Jun 2017
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    Quote Originally Posted by Scali View Post
    I take it you had to order a certain minimum number of PCBs?
    In which case, are you interested in selling a few to people such as myself, who may want to build their own clone (I already built the Lo-Tech Tandy card)?
    Alternatively, I'd also be interested in one if you assemble it yourself.
    I had to order 10 PCBs and I believe the fab sent me 12 or 13 boards so I certainly do have some spares that I can sell if people are interested.

    Not sure what shipping will be to The Netherlands - I will have to get an estimate and get back to you.

    All components are through-hole so the boards are quite easy to assemble. I used a socket for all ICs except for the amp because the datasheet specifically advises against using a socket for some reason (probably noise levels.)

    I should have enough 74 series logic chips to build a few more boards but I don't have any more SAA1099 chips at the moment and I will need to find a pot that will fit on an ISA card for the volume control.

    If there is enough interest in bare boards or assembled cards I am certainly willing to entertain the idea of doing a larger order of PCBs and components.

  7. #7
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    Excellent... if you could put together a Bill-of-Materials, I suppose I could order everything required from eg mouser.com, except for the SAA1099 chips, which I can probably get off Ebay or such (it's where I got the SN76489/SN76496 chips for the Tandy card as well, cost next to nothing, from China).

  8. #8
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    Jun 2017
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    A brief parts list is available on Github

    Mouser should have everything except for the TEA2025 amplifier and the SAA1099 chips. I got most of my parts from Tayda Electronics and the exact audio jack I used is available at http://www.taydaelectronics.com/3-5m...udio-jack.html although most any 3.5mm jack should work as long as the PCB footprint matches.

    The TEA2025 and SAA1099 both should be available from multiple Chinese sellers. I got my SAA1099 chips from UTsource since in my experience they tend to use proper ESD-safe packaging and their prices are usually close to other Chinese sellers but of course eBay is an option as well. They probably have the TEA2025 as well although I got that from Tayda.

    If you buy from UTSource, make sure the seller is listed as "UTSOURCE" because they do list items from other sellers on their website.

    If anyone wants any of my spare PCBs, send me a PM. I am willing to sell them for $10 per board plus shipping (should be about $5 for those in the USA, more elsewhere.)

  9. #9

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    I may be interested in a bare PCB if you decide to sell just the PCBs. I like building things, and have a pile of existing 74XX chips from other projects.

  10. #10

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    I'd like a board and bits kit to assemble. It's relaxing.. lol

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