Emax

Have you considered just using an old Mac with Alchemy 3.0? I do this quite reliably for sample dumps between my EMAX and Mac 9600 and the cost of an old Mac is most likely less than a USB->RS422 converter.




--- On Mon, 10/27/08, esynthesist <esynthesist@...> wrote:

> From: esynthesist <esynthesist@...>
> Subject: [emax] Re: Emax SCSI Upgrade kits - WARNING...POSSIBLE RANT
> To: emax@yahoogroups.com
> Date: Monday, October 27, 2008, 4:41 PM
> OK, other members seem to confirm that the additional 4
> holes are on 
> the PCB already :-)
> 
> About my RS422 experiments: in fact I'm able to
> communicate with the 
> EII, it's just that the communication is a little bit
> unreliable when 
> receiving data from the EII, and *very* unreliable when
> transmitting 
> data to the EII. In my opinion the only two possible causes
> can be:
> - problem in voltage level
> - problem with timings.
> Since receiving data goes quite well (18-20 seconds
> including re-
> handshakes compared to the 11 seconds without re-handshakes
> on a Mac) 
> I don't think there are timing problems. Both the EII
> port and the 
> USB/RS422 converter are clocked at 500kbaud - note I had to
> buy a 
> specific USB/RS422 converter since the standard ones are
> not capable 
> of being clocked at 500kbaud. But still this is a different
> situation 
> compared with the Mac since the Mac's serial port is
> externally 
> clocked by the EII's clock, which guarantees of course
> that they are 
> synced. This external clocking is simply not available on
> RS422 PC 
> ports.
> My guess however is that the USB/RS422 transmit signal is
> too low for 
> the EII (or more particularly: the differential transmit
> level is too 
> low). I'm pretty convinced about this because
> "getting a bank from 
> EII" goes very well while "sending a bank to
> EII" is a disaster. 
> Sending data from PC to EII requires of course a lot more
> bytes to be 
> sent than receiving data, and my experiments show that the
> stream of 
> data seems to be partly "destroyed" when it
> arrives at the EII (the 
> EII answers with a NACK or keeps waiting for more data
> because it 
> thinks not all data have been received yet).
> However I don't have a digital scope to confirm this...
> but I'm 
> really thinking about buying one now ! Now even when the
> scope 
> confirms my thoughts, the next question is what I should do
> to solve 
> the problem. Building custom hardware seems not very
> attractive from 
> the perspective of potential EII users I guess...
> 
> Mmmm... interesting but frustrating... just like upgrading
> the Emax 
> with SCSI :-)
> 
> PS: I'm still waiting for a reply from my synth repair
> guy concerning 
> the SCSI upgrade.
> 
> ///E-Synthesist
> 
> 
> 
> 
> --- In emax@yahoogroups.com, Ted Summers <djtbs1@...>
> wrote:
> >
> > Thanks for the encouragement.  From my understanding,
> the holes 
> are  
> > already there for the socket.....
> > 
> >  >> In fact I think this expense problem is part
> of and compensated 
> by
> > the challenge/kick/hobby/appreciation...isn't it ?
> > True.....
> > 
> > On your project---
> > 
> > Regarding the USB converters- are you working on Mac
> or Laptop 
> that  
> > has no serial? The serial is RS422, at 500kilobits
> (not bytes) per  
> > second, according to the service manual. it also says
> the RS422 is  
> > using differential mode.
> > Here is a web page discussing that:
> > http://www.lammertbies.nl/comm/info/RS-422.html
> > 
> > Maybe you already know about these things, but just in
> case.....
> > 
> > I would think the biggest challenge there would be
> timing between 
> USB  
> > and the RS422, and I believe RS422 uses different
> signal levels. 
> It  
> > may be that the USB is using too low of signal
> levels....
> > 
> > just a couple of thoughts.
> > 
> > Regards,
> > Ted
> > 
> > 
> > 
> > On Oct 25, 2008, at 9:36 AM, esynthesist wrote:
> > 
> > I think quite some Emax users really appreciate your
> efforts !
> > 
> > So do I, and I didn't even buy your SCSI kit (yet)
> :-)
> > 
> > In fact I was very enthusiastic when I read about your
> SCSI kit and 
> I
> > was even more thrilled when I discovered my Emax SE
> keyboard had a
> > Rev2 board.
> > But... my enthusiasm kind of disappeared when I
> started reading the
> > SCSI Upgrade instructions. My headache reached a
> climax when I read
> > that a 24-pin IC socket should be removed and replaced
> by an 28-pin
> > socket (what about the PCB holes for the 4 additional
> sockets ??)
> > So as other members already mentioned: the problem is
> probably not
> > the price (which is really fair) but the technological
> challenge and
> > the risk to destroy a perfectly working Emax.
> > Personally I'm thinking about outsourcing this
> upgrade job to my
> > synth repair guy but I have to ask him a price
> estimation first.
> > 
> > Of course this kind of upgrade/rev.engineering
> activities take a lot
> > of time and may also require some "personal
> cash" investment.
> > E.g. for developing EMXP and making sure everything
> works fine I had
> > to do quite some investments. At the beginning I
> thought that having
> > an EMAX SE, an EMAX-II, an EII+, and an EIIIXS would
> be sufficient
> > for making sure that the software works on all
> samplers of those Emu
> > families.
> > But it seemed I had to buy an Emax Plus and a
> "real" EIII also,
> > machines I didn't need otherwise. Especially the
> EIII was very
> > expensive and I'm still not really using it -
> it's just sitting 
> there
> > for test purposes of EMXP. (true, I can sell them
> again when I stop
> > developing this software)
> > Another example: for the past few weeks I was trying
> to add serial
> > communication to EMXP for the Emax and EII. But to
> come to the
> > conclusion that this will probably not be possible, I
> first had to
> > buy two USB-RS422 converters and one USB-RS232
> converter.
> > I'm glad I didn't buy a 1000+ EUR digital
> oscilloscope yet :-)
> > 
> > But I don't really care about these expenses,
> fortunately I don't
> > have a wife :-)
> > In fact I think this expense problem is part of and
> compensated by
> > the challenge/kick/hobby/appreciation...isn't it ?
> > The fact that we are helping some Emu fans out there
> and that they
> > really appreciate our efforts could be our main
> driver/objective.
> > 
> > Many thanks for the efforts and I'll probably send
> you an order in
> > the coming days/weeks !
> > 
> > ///E-Synthesist
> > 
> > --- In emax@yahoogroups.com, "Ted Summers"
> <djtbs1@> wrote:
> >  >
> >  > Thanks for your words of encouragement. $2500-
> wow. My wife 
> freaked
> > when she
> >  > realized I had spent the $900 (although she
> somewhat chilled out
> > when I told
> >  > her that I had made some of it back)---- I
> couldn't imagine the
> > amount of
> >  > your project .... I hope people start coming
> through for you as
> > well.
> >  >
> >  > It is all very easy for people to say it could
> be done cheaper. I
> > think we
> >  > both know it isn't all as easy as it sounds.
> You never really 
> know
> > what it
> >  > is gonna take until you get into it. And once
> you get into it, 
> you
> > feel like
> >  > you wasted your money / time if you just drop
> your effort too....
> > catch 22.
> >  >
> >  > Best of Luck!
> >  >
> >  > Regards,
> >  > Ted
> >  >
> >  >
> >  > [Non-text portions of this message have been
> removed]
> >  >
> > 
> > 
> > 
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >