[Coco] Cheap alternative to the DE-1?

[Dave Philipsen]

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