Max Modification Instructions	R. Grieb	9/10/2013

	Please read these instructions before doing anything to your Max.

	The Max pc bd is impaled on eight spikes on 
the four corners of two brackets attached to the bottom of
the synthesizer.  On re-assembly, each of these spikes should 
have an insulating washer on it to prevent the board from making 
electrical contact to the brackets.

	After you have removed the front panel assy from these spikes and
from the rest of the synth, you may want to mark the orientation of the 
keyboard connector before you unplug it.  This connector is not keyed.
Plugging it in backwards won't damage anything, but the keyboard won't work.
With the electronics assy removed from the synth, you will need to remove 
the pc board from it.  Remove the volume knob by pulling it straight up.
Place the electronics assy in front of you, with the back panel away from you.
Put something under the two ends, so that the weight is on the front panel, 
and not on the potentiometer shaft or buttons.  Remove the two screws that 
hold the pc board to the rear of the front panel.  Now you can tilt the edge
of the pc that is toward you up.  The power switch will still be sticking out 
of its cutout in the back panel, but once you have the board tilted up enough, 
you can slide it towards you, away from the rear panel, being careful that all 
of the switch rubber caps are free from the front panel.

	Now you need to either disable the two RAM chips or remove them.  To 
disable them, you could cut the CEb pin (18) near the pc board with nippy cutters, 
bend it up, and then solder a wire to the pin and connect the other end to +5V.  
Another option would be to cut the traces that connect to the CEb pins, and 
then tie the two CEb pins to +5V.  To remove the chips, take small diagonal or 
nippy cutters and cut each pin of the chip at the top of the lead, where it 
connects to the plastic package.  Keep the cutters away from the pc bd to prevent 
any damage to it.  Once all the leads of the chip are cut, remove the body of 
the RAM chip, leaving just the pins standing up on the pc bd.  Now use a soldering 
iron to heat each pin individually and pull it out with tweezers or small 
needle-nose pliers.  Once all of the pins are removed, clean both sides of the pc bd
with isopropyl alcohol and Q-tips, or some other type of cleaner.  This is the 
preferred way of removing a chip if protecting the pc bd is important.  Of course, 
the chip cannot be re-used.

      Assemble the memory board, using the components provided and the component
placement diagram.  The two IC sockets have a notch at one end that should be near 
pin 1 of the IC.  The two SMT capacitors on the bottom of the pc bd are optional
and are probably not needed.  There is also an extra eyelet for connecting ground 
on the memory board to ground on the Max main bd, but this is also probably not needed.
Use the IC socket with round pins for the NVRAM and the other one for the EPROM.
When installing the gold pins that connect the memory board to the Max EPROM socket,
the thicker pins are soldered to the Max memory board.  These headers mount on the 
underside of the memory board.  To get them straight, I use a machined-pin IC socket
to hold the non-soldered side of the pins apart.  You don't need to plug the pins 
all the way into the socket.  Just enough to hold them 0.6" apart while you are 
soldering the thicker ends to the pc bd.  Solder just one or two pins of the header
first, then check that they are perpendicular to the pc bd before soldering the 
remaining pins.  Be careful not to bend any of the header pins as they will break 
if bent more than a few times.  Make sure you install the diodes with the correct
orientation.   The end with the line (cathode) on it is clearly indicated on the 
component placement diagram.

	Assuming you have either removed or disabled both U112 and U111 RAM chips,
you are now ready to plug the memory board into the EPROM socket on the Max.  Be careful
not to bend any of the gold pins as it is easy to do so.  You can bend them back slowly
once or twice, but after that they may break.   My Max pc bd has a machined-pin socket on it
for the EPROM, so the round pins will probably support the weight of the memory board and 
keep it from coming unplugged.  In general, though, it's probably best to use a cable tie
to hold the memory board in the EPROM socket and keep it from coming unplugged.  The tie
would run under the EPROM socket on the Max main bd, and over the EPROM socket on the memory
board, but under the EPROM.  The memory board will be upside-down after the Max is re-assembled.

	There are five wires which need to connect from eyelets on the memory board
to pts on the Max main board.  These connect as follows:

Eyelet	Signal		Connection point	Measured wire length (insulated part)
W1	Z80A15		Z80 pin 5		6"
W3	Z80WRb		Z80 pin 22		3.75"		
W5	Z80RDb		Z80 pin 21		4.0"
W2	U111CEb		U111 pin 18		2.25"
W4	U112CEb		U12 pin 18		2.625"

If you are pre-cutting wire, allow a little extra in case you need it, but try to keep
the wires short.

(Eyelets are listed in their order on the edge of the memory board.  Please refer to the 
component placement diagram to make sure you know which is which)

	Some of these signals could be connected to the same signal at other locations,
but these points should allow the shortest wire lengths.  Please keep the wires as short
as possible, within reason.  Solid core wire is better for this kind of job than stranded,
as there is less chance of a rogue strand shorting out to an adjacent pin.  Check your solder
connections on the ends that connect to the Max pc bd, to make sure there are no shorts to 
nearby signals.

Initial testing:

	After you are sure that your soldering is good and you have not created any
shorts on either board, it's time to apply power.

	I would suggest that you power up the Max main pc bd with the memory board installed,
before you re-fasten it to the front panel.  Make sure it's not touching anything that
could cause a short and damage it. You should see a "9" on the display for an instant, 
then a "7".  The 7 indicates that the program checksum failed, which it should at this point.
Press Track 1 to load the Max factory programs and the two demo songs.  You should see the 
display counting from 1-6 as it tunes the voices.  If that looks good, reconnect the keyboard 
and make sure everything is OK.  Play demo song 1, and try the keyboard as well.   The next
time you power up the Max, you should not see the 7.  The 9 will always flash on the display
at power up.  This helps with debugging if there is a problem.

Using the new features:

	Program loading from EPROM into RAM only takes place when a checksum mismatch 
occurs (RAM is corrupted) or if you hold down Track Volume Up when powering on the synth.
In that case you should see an "8" on the display, and Track 1-3 LED's lit.  You can press:

Track 1 to load the 80 Max factory programs plus 20 Six Track unison programs from 80-99

Track 2 to load the 100 Six Track factory programs

Track 3 to load the 100 Multi-Trak factory programs in the "B" order.

	You will have this same choice if the program checksum fails, but this should not
happen.  The checksum is updated whenever you download a program via MIDI, load a set of 
programs from EPROM, or use one of the special commands below.

	Note that the Max demo songs are always loaded, but will only sound "correct" 
when the Max factory sounds have been loaded.

	If you see the "7" or "8" (checksum failure) on the display, but don't want to 
load programs, you can hit the Track Volume Down button.

	To copy the current program, which perhaps has been modified using CC MIDI messages,
to program 99 location, hold Transpose and press Speed Up.  Since program 99 is at the top 
of the programs, Up seemed logical here.  Once you have copied this program to 99, you can 
select 99 to listen to it.  

	To copy the contents of program 99 to another program location, first select that program
using the normal Max method.  Now hold Transpose and press Speed Down.  (You will need to re-select
this program to hear the changes)  Using this and the previous operation, it's possible to copy a 
modified program to any of the 100 program storage locations (re-writing program location 99 in the 
process)