Emax

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]
>