I'm not too deep on this, but I've heard from coworkers that have done some
general latency testing (not related to ZVG) that USB can introduce quite a
bit of latency compared to even an add-on parallel port, although a lot of
the newer add-on parallel ports can be terrible too. They takeaway they
had from these tests is that anyone that really wants low latency should
buy an ancient PC. :(
Gary
On Mon, Apr 16, 2012 at 3:59 PM, Jeremy Abel <jeremyabel@gmail.com> wrote:
> Well crap, there goes that idea. I'm going to call Zonn, see if he's into
> me redesigning and recoding the zvg for usb. That's pretty much the only
> option at this point, assuming he set the lock bits (although I never have
> for any of my projects...)
>
>
> On Mon, Apr 16, 2012 at 6:39 PM, GamingDevices <gamingdevices@tx.rr.com>wrote:
>
>> The Atmel ATmega16 & ATtiny2313 devices used in the ZVG have lock bits,
>> so I doubt that you can just read the part.
>>
>> Mike
>>
>>
>>
>>
>> On 4/16/2012 4:59 PM, Jeremy Abel wrote:
>>
>> Hello all!
>>
>> So, I've got my vector monitor (or at least the post office does; I
>> have to go pick it up), and I've been investigating ways to control it. So
>> far, the ZVG seems like the best / only option. However, they seem to be
>> hard to come by, and a bit out of my price range, not to mention the fact
>> that they just aren't being made anymore. Making it even more complicated,
>> I don't even have a PC with a parallel port (only a macbook). Instead, I've
>> come up with several other options, which I will talk about below.
>>
>> Using the schematic that's available online, I've managed to re-enter
>> the whole thing into EagleCAD, and have begun to design my own board for
>> it, using only through-hole parts (because I don't have the patience /
>> skill to solder SMDs). So far, only the power supply area is done, because
>> I don't want to put too much effort into it before getting some more
>> information about the whole thing. I'm doing this only because it would
>> cost me $100 to print the board, and then $50 in parts, which is about $100
>> less than I'd end up paying for an original ZVG. There is one snag though:
>> basically, I need the firmware that goes on the two Atmel chips. Without
>> that, I might as well not even bother. So, I've come up with some solutions
>> to that problem. Here's what I've been thinking:
>>
>> *Option 1: *I somehow manage to get ahold of Zonn (no luck with that so
>> far), and somehow convince him to open-source the firmware (something he
>> talked about here<http://www.ukvac.com/forum/forum_posts.asp?TID=328991&PID=752487&SID=5dbcd2zb-da95-5c822ae9-cezbbae5-3z84c2e1&title=zektor-zvg-limited-run-hurry#752487>,
>> about a year ago). With access to the actual code, I could pretty easily
>> convert it to communicate over USB. With Zonn's permission, I would then
>> open source the entire thing, and thus you all would have a lovely new
>> open-source USB-enabled ZVG. This, I think, is the best option, as I don't
>> need anyone to dump the firmware for me, I don't need to logic probe the
>> thing and figure out what's being sent over the parallel port, and I don't
>> need to program an interpreter to convert the thing into USB.
>>
>> *Option 2*: Someone with a ZVG solders up headers to J5 and J6, and
>> uses an AVR programmer to read off the firmware and sends it to me as a hex
>> file. I can then use this to program my own atmel chips, and proceed.
>> However, this will make it difficult for me to get around the parallel port
>> problem without a large amount of logic-probing and then adding another
>> microcontroller to convert the signals being sent to the parallel port into
>> signals I can send over USB. In order to keep Zonn's IP safe, I'd keep the
>> whole thing to myself. Still, this feels shady.
>>
>> *Option 3: *I buy a ZVG from someone, dump the firmware myself, then
>> sell it back to someone else. This feels just as shady, maybe more, than
>> option 2.
>>
>> What do you all think about all of this? I'd love to get the ball
>> rolling on this, preferably on option 1 if anyone knows how to get ahold of
>> Zonn.
>>
>> Thanks,
>> ~Jeremy
>>
>>
>>
>
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Received on Mon Apr 16 19:05:03 2012
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