[Coco] Cheap alternative to the DE-1?

[Zippster]

Whoops… thinking in digital…  :)

- Ed


> On Oct 28, 2015, at 3:15 PM, Dave Philipsen <dave at davebiz.com> wrote:
> 
> Actually, three resistors per channel would yield 512 colors (including black). Three bits yields 8 combinations or voltage levels or colors per channel.  There are 3 colors (RGB) or channels so 8 to the third power is 512.
> 
> If you bump it up to four bits per channel you can have 4096 colors.
> 
> Dave
> 
> 
> On 2015-10-28 13:40, Zippster wrote:
>> Probably a binary weighted DAC (resistor network) like many dev boards.
>> Three resistors per channel should give 64 colors (4 levels including
>> ground level per channel).
>> Add another bit per channel to go to 125.
>> USB blaster clones are dirt cheap on eBay.  Like $4 or so.
>> - Ed
>>> On Oct 28, 2015, at 12:51 PM, Dave Philipsen <dave at davebiz.com> wrote:
>>> Well, the DE-1 doesn't have a DAC either, just a resistor network.  You could probably hack that board though to get more colors if you wanted.
>>> Another thing you'd have to consider on this board is that it doesn't have the built in USB Blaster like the DE1.  You'd have to buy a blaster on eBay or somewhere.  If you are patient you can sometimes find a DE1 on eBay that will go for around $90 or so.  I even saw one go for around $55 bucks once.  My experience finds that they are usually in excellent condition.
>>> Dave
>>> On 2015-10-28 12:32, tim franklinlabs.com wrote:
>>>> Yeah, you're probably right. I found another problem too. I found the
>>>>  schematic for it and they limit the video to 8 colors. Not DAC to the
>>>>  VGA connector. Just logic.
>>>>  Manual: [1]http://www.dukelanovic.com/A-C8V4%20MANUAL.pdf
>>>>  Schematic:
>>>>  [2]http://d1.amobbs.com/bbs_upload782111/files_44/ourdev_671042EUF7C8.p
>>>>  df
>>>>  Shorter links too LOL!
>>>>    On October 28, 2015 at 12:23 PM Dave Philipsen <dave at davebiz.com>
>>>>    wrote:
>>>>    FWIW, I think Gary's project uses north of 9,000 LEs which means
>>>>    that
>>>>    even if you can trim it down to fit you won't have a lot of extra
>>>>    space
>>>>    for future expansion/additions. Not trying to be negative...I hope
>>>>    you
>>>>    get it working...would be an interesting project.
>>>>    Dave Philipsen
>>>>    On 2015-10-28 07:23, tim franklinlabs.com wrote:
>>>>    > I ran across this while surfing E-Pray this morning. It looks
>>>>    > interesting. For those, like me, who are interested in FPGA's,
>>>>    this
>>>>    > $70.00 unit seems to have everything needed to port Gary Beckers
>>>>    > CoCoFPGA to it:
>>>>    >
>>>>    >
>>>>    >
>>>>    [1]http://www.ebay.com/itm/Altera-Cyclone-NIOS-II-SOPC-FPGA-Developm
>>>>    ent
>>>>    >
>>>>    >
>>>>    -Learning-Board-EP2C8Q208C8N-LCD1602/272020523309?_trksid=p2054897.c
>>>>    100
>>>>    >
>>>>    >
>>>>    204.m3164&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D2
>>>>    014
>>>>    >
>>>>    >
>>>>    0407115239%26meid%3D8d211755ec994eff8913982e805be0c8%26pid%3D100204%
>>>>    26r
>>>>    > k%3D12%26rkt%3D21%26sd%3D261661704545
>>>>    >
>>>>    > It uses a smaller FPGA so there may be a limit here. I'm not sure
>>>>    > how
>>>>    > many LE's Gary's code uses.
>>>>    >
>>>>    > This board: EP2C8 8,256 LE's
>>>>    > DE-1: EP2C20 18,752 LE's
>>>>    >
>>>>    > Also, there are only 2 PLL's and I'm not sure if both are
>>>>    connected
>>>>    > to
>>>>    > clocks. I bought a small FPGA that had 4 clock inputs with 2
>>>>    PLL's.
>>>>    > The
>>>>    > moron who designed the board connected the clock to one of the CLK
>>>>    > pins
>>>>    > not connected to the PLL's.
>>>>    >
>>>>    > This board: 2 PLL's This assumes there are clocks connected to
>>>>    > both.
>>>>    > DE-1: 4 PLL's DE-1 uses only 3 (one connected to the
>>>>    > external clock)
>>>>    >
>>>>    > Since Gary posted an "almost" up to date project of his 3.0 FPGA
>>>>    > code,
>>>>    > i went ahead and bought one to see if I can port it. It comes from
>>>>    > China, so it wont arrive for a while (slow boat from china joke in
>>>>    > real
>>>>    > life). I'll keep everyone posted.
>>>>    >
>>>>    > References
>>>>    >
>>>>    > 1.
>>>>    >
>>>>    http://www.ebay.com/itm/Altera-Cyclone-NIOS-II-SOPC-FPGA-Development
>>>>    -Learning-Board-EP2C8Q208C8N-LCD1602/272020523309?_trksid=p2054897.c
>>>>    100204.m3164&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%
>>>>    3D20140407115239%26meid%3D8d211755ec994eff8913982e805be0c8%26pid%3D1
>>>>    00204%26rk%3D12%26rkt%3D21%26sd%3D261661704545
>>>>    --
>>>>    Coco mailing list
>>>>    Coco at maltedmedia.com
>>>>    https://pairlist5.pair.net/mailman/listinfo/coco
>>>> References
>>>>  1. http://www.dukelanovic.com/A-C8V4%20MANUAL.pdf
>>>>  2. http://d1.amobbs.com/bbs_upload782111/files_44/ourdev_671042EUF7C8.pdf
> 
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