Emax

Yesterday I managed to buy a SCSI flatcable and and external 
connector, so I installed them immediately in the Emax Plus.
YES ! It works, I can use the external zipdrive now, so the chips and 
piggyback board seem compatible.
Maybe I will also put an internal HD in the sampler, I have a few 
EMAX-II spare hard disks. I just need to figure out the power supply, 
as the psu cable/connector to an internal HD is not available in the 
sampler. I noticed however that the power supply connector for the 
floppy drive (right side of the main board) has 8 pins of which only 
the left 4 are connected to the floppy. Can I use the other 4 for the 
internal HD ?

About the LCD: sometimes it works, sometimes it doesn't. So I'll have 
to repair it. I'm still not sure about the EMAX-II compatibility of 
the frontpanel board. Emulatorarchive mentions the following on 
replacing EMAX LCDs:

"There are a variety of LCD's you can use as replacements, some have 
the same blue backlight, others have a green or yellow backlight 
colour - as per Emax II's. You can use LCD's with EL backlights (as 
per the original) or experiment with LED backlights which last longer 
but need a different power supply for the LED's (typically 4.2V 120mA 
rather than 140VAC 400 Hz )." 

Maybe a stupid question, but how do you recognize a LED backlight 
versus an EL backlight ? Do they both have grey/black characters on a 
lighted colour background (green on EMAX-II, blue on EMAX) ?

///E-Synthesist

--- In emax@yahoogroups.com, "elmacaco X" <elmacaco@...> wrote:
>
> 
> 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]
> > > >
> > >
> > >
> > >
> >
> >
> >
> >[Non-text portions of this message have been removed]
> >
>