Emax

Now this is a discussion!!!

Just some notes from my experience,

I used the Emulator archive's way, of getting a internal/external scsi 
adaptor, and an internal scsi ribbon cable with 3 connectors to connect my 
harddrive, the board, and the adaptor.

I didn't do any of the hard drive termination steps that Ted mentioned, I 
just hooked it up as is, and it has worked fine with a zip 100.  I don't 
remember if I have it terminated at the zip as well.  I seem to recall it 
didn't matter, but it's not set up right now.

maybe there is a way you can disconnect the powre to the backlight just to 
test if it solves the problem?

best of luck in the repair!!!



>From: "ted Summers" <djtbs1@...>
>Reply-To: emax@yahoogroups.com
>To: emax@yahoogroups.com
>Subject: Re: [emax] Re: Repair and SCSI Upgrade question
>Date: Sun, 17 Sep 2006 23:32:17 -0700
>
>I am just going from what Rob from emulator archive had told me in an
>email a couple of years ago. I was looking at getting replacement LCD
>displays.
>Rob said the original emax had an EL (electro-luminescent) LCD
>display which was blue (correctly- I sourced that part).
>The emax 2 that had a green display he said was an LED backlit
>display. He said the two weren't directly interchangeable. I think
>the only way to know for sure would be to measure. While the voltage
>is high, the amps wouldnt be. But I don't have an emax2 to check it
>for you (as yes, BTW- I have worked as an electronics repair
>technician). If you are worried, insulate your probes by putting heat
>shrink on the meter probes, heat it, then only cut off a small bit so
>just the tips are exposed metal.... just a "tech tip"
>
>RE the scsi- that should work. I would think if you did the transpose
>to change the scsi ID, then you should be able to do the hard drive
>stuff with your zip. If not- find an old black and white mac. The
>original ones (I found about 5 at my local goodwill a while back)
>have the same drive the emax had. I might be able to help you find
>one for reasonable if you  are unable to locate.
>
>Thanks,
>Ted
>
>
>On Sep 17, 2006, at 4:33 AM, esynthesist wrote:
>
> > Thanks Ted. Are you sure the Emax-II doesn't use an invertor ?
> > I'm not a technician, but on its main board there's a black cube on
> > almost the exact same place as the one in the Emax Plus (labeled
> > AH125 in the Emax-II). Or is this thing not used for the display ?
> >
> > I found this website telling that the LCD display replacement should
> > be the same for Emulator II, Emax and Emax-II
> > (http://members.aon.at/virtual-music/zonen_e/e_products_emu.htm).
> >
> > Of course I could measure voltage on those pins and compare, but I
> > don't like measuring high voltages on two pins so close to each
> > other :-)
> >
> > About the SCSI: the sampler doesn't have an internal HD, so I guess I
> > can simply connect the main 50-pin connector from the main board
> > directly to the new DB25 connector. I know I won't be able to boot
> > from the external ZIP, but that's not a problem.
> > I'm just wondering whether that "OS" chip on IC13 is OK...
> >
> > By the way: since I don't have any SCSI device connected to the
> > sampler at the moment, I noticed that the Plus OS is not very
> > practical: you can boot the Plus OS from floppy, and it also loads
> > the bank from that floppy, but when you want to load another floppy,
> > you can't. The sampler says 'HD Catalog error' because it first wants
> > to find the banks available on HD, and than give also the '00'
> > possibility to load from floppy. As it doesn't find a HD, it gives an
> > error instead of the Floppy alternative.
> > Seems the engineers didn't really think about that one :-)
> > Well... I'm using the Emax-SE OS at the moment...
> >
> > ///E-Synthesist
> >
> > --- In emax@yahoogroups.com, "ted Summers" <djtbs1@...> wrote:
> > >
> > > From my understanding, the Emax 2 LCD is backlit by 5 volts and
> > > doesn't use the inverter (which is ac and not 5 volts). The two
> > pins
> > > on one end of the display are coming from the inverter. You could
> > > take a standard LCD display that is the correct size, and break
> > the
> > > conection on the LCD board from the two pins, then wire +5 from
> > the
> > > power supply to those points. The same would be true of the EMAX2
> > > display). The inverter power would destroy the emax2 backlighting.
> > I
> > > dunno what other harm would be caused....
> > >
> > > As to the SCSI- if you have scsi you should be able to add a port
> > to
> > > the back. SCSI is scsi. The thing is this, there are really two
> > ways
> > > of doing it.... If there is a plug on the board you can come off
> > of
> > > it (I did this on mine).
> > >
> > > I dunno how much you know about scsi- so here is how you would
> > make
> > > this work, if you don't know scsi
> > >
> > > If there is no port on the board, get a SCSI cable with an
> > external
> > > end (DB25), and two 50pin connectors (like on the board and drive
> > > connectors) and replace the cable that is in the emax.
> > >
> > > On the hard drive is a set of 3 resistor networks by the ribbon
> > cable
> > > connection. They might be blue, yellow, red, or black, but are
> > > removable. They have 8 pins in a single row. These resistors
> > > terminate the SCSI chain. By removing them, you can add an
> > additional
> > > device to the end of that chain (ie- cabling). When you remove
> > these
> > > and extend the chain you MUST have a terminator on the external
> > plug
> > > if nothing is hooked up to boot the machine, but if you are getting
> > a
> > > ZIP drive, it will have termination in it, so as long as it was
> > > always hooked, you wouldn't need the plug on the external
> > connection.
> > >
> > > And that, as they say, is that.....
> > >
> > > Hope it is clear as mud. And thanks for all the work you have done
> > > for us on the Emax programs (though I haven't used them...yet)
> > >
> > > Regards,
> > > Ted
> > >
> > > On Sep 16, 2006, at 10:26 AM, esynthesist wrote:
> > >
> > > > I need some help !
> > > >
> > > > I bought the Emax Plus Rack I was talking about earlier. It's
> > a "Plus
> > > > SE with SCSI", serial number 002 (!).
> > > > The sampler works but it has a display problem and quite a strange
> > > > SCSI chipset:
> > > >
> > > > 1. The DISPLAY Problem
> > > > ----------------------
> > > >
> > > > First of all this machine has a problem with the LCD display.
> > > > After pushing some buttons, the contrast on the second line goes
> > to
> > > > zero and the contrast on the first line goes to the maximum.
> > > > There's also an annoying high frequency noise coming from the main
> > > > board (invertor ?) and also from the display (this only when the
> > > > problem occurs)
> > > >
> > > > Now I also have a spare Emax-II rack with a perfectly working
> > > > frontpanel PCB board & display.
> > > > I compared the two boards and they look almost the same:
> > > > - board in Emax Plus = 'Emax Rackpanel version 2 1986' PC328 REV B
> > > > ASSY REV A (AF133)
> > > > - board in Emax II = 'Emax Rackpanel version 2 1986' PC328 REV D
> > > > (no assy) (AF133)
> > > > The two capacitors on the board however have different numbers -
> > > > these are actually the only two components on the board which are
> > not
> > > > buttons, sliders, display, lights or chip :-)
> > > >
> > > > My question:
> > > > Do you think it's safe to switch these boards ? Maybe it won't
> > work,
> > > > that's no problem, but I just want to be sure the Emax Plus won't
> > get
> > > > damaged by this experiment.
> > > > Anyone who can give me some advice ???
> > > >
> > > > 2. The STRANGE Thing
> > > > --------------------
> > > >
> > > > I also want to add an external SCSI port to the sampler. It's not
> > > > fitted on the board, and there's no hole in the backpanel either.
> > > > Now I checked the specs from the sampler:
> > > > - it's a PC333 Rev B main board
> > > > - the SCSI 5380 chip is installed on IC6
> > > > - the IP379A HD/Plus TIM PAL chip is installed on IC49
> > > > ...
> > > > - but on IC13 there's a 24-pin IP349C chip instead of the IP355
> > > > mentioned on www.emulatorarchive.com.
> > > > However, it is installed on an 28-pin socket. There's also an
> > IP349
> > > > Rev 3 'piggyback' board installed at the left of the main PC333.
> > > >
> > > > This is a situation not described in the SCSI Upgrade
> > instructions on
> > > > www.emulatorarchive.com.
> > > > According to the upgrade instructions either the 3 chips have to
> > be
> > > > installed or all 3 chips should already have been factory-
> > installed.
> > > > If they're not installed, the IC13 should have no 28 pin socket
> > yet.
> > > > But mine has...
> > > > I really don't know what machine I bought, it seems like a
> > prototype
> > > > of the Emax Plus...
> > > >
> > > > Anyway: can anyone confirm that the specs are sufficient, so that
> > I
> > > > just have to add a DB25 SCSI port and a flat cable ?
> > > > Or should I simply try & check ?
> > > >
> > > > Thanks !!
> > > >
> > > > ///E-Synthesist
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
>
>
>
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