ComputerVoltageSources

Fine.  A couple of notes.  The Samsung controller is compatible with 
the Hitachi controller so this means all of these parallel LCD 
Assemblies will be compatible.

I would propose an ATTINY2313 for the LCD support PCB.  Note that this 
PCB would contain only the following parts:

ATTINY2313 20 pin DIP
14 pin header to connect to LCD Assembly
3 or 4 pin header to connect to CVS PC
  (Tx, Reset, Ground, and possibly +5)
Input power connector for the LCD Assembly backlight
Current limit resistor for the LCD Assembly backlight
8 MHz crystal and two 22 pF capacitors
Optional 6 pin header to program the ATTINY2313 in-circuit
Optional contrast potentiometer (my experience is to run the LCD
  at full contrast with no potentiometer)

Alternatives for the +5 volt power are:
1) Use the CVS PCB.  Power for the ATTINY2313 is 6 mA. The LCD 
Assembly selected has a separate 2 pin connector for the backlight. 
This could be powered from +15 volts with a current limit resistor or 
from +5 volts with a current limit resistor if available from the 
power supply.

2) Local +5 volt regulation for the ATTINY2313 and power the backlight 
from +15 volts with a current limit resistor.

3) Power both the ATTINY2313 and backlight from +5 volts with a 
current limit resistor if available from the power supply.

Dave

--- In ComputerVoltageSources@yahoogroups.com, "John Loffink" 
<jloffink@...> wrote:
>
> Oop!  Not offlist after all.  
> 
> No matter.  If we named these things we'd be able to keep them
> straight.  My suggestions, these can just be placeholders:
> 
> CVS PCB = New custom PCB designed by Harry to populate the BASIC
> ATOM PRO and associated circuitry
>
> LCD Support PCB = New custom PCB to contain intermediary
> microcontroller (ATMEGA proposed by Dave) to translate
> serial/MIDI from CVS PCB to LCD Assembly parallel format.
>
> LCD Assembly = Piece as bought from Lumex/Mouser/Digi-Key.
> Includes the Samsung LSI controller.