*Note: All Electronics is now out of business*
I picked this display from "All Electronics" - a surplus Electronics store- for $12(now only $6). not a bad price for this size of display. I figured for the price, it's worth giving it a shot. Note from the Reviews at All Electronics: Some people had issues, and most, after some work, got the unit to work. One issue was the display flicker during fast writes, I found that some of this was due to not checking if the display was doing a refresh and write timing. When connected via PIO ports to drive it, similar to hooking to an Arduino, I got that problem with fast writes. When I connected the display directly to the Z80 bus, it could write faster and had none of the dim flicker effects. It could be the timing of the Write signal rise and fall times.
Hope this will be helpful for those in the future who get a display with a SED1330 controller or which library is being used for the SED1335 controller that is compatible. A Google search will pull up the SED1335 C library.
While I am connecting it to the Z80, information on my progress of connecting and setting up the display would be useful in using with other Micro's.
A few features of the unit:
8080/Z80 compatible bus interface
Multiple Planes to mix text and overlay graphics.
Virtual display area, allows hardware scrolling and Multiple screens
This could allow to do page flips, draw in background so user does not see screen creation.
The datasheet that came with it is a poor photocopy, and the PDF's I seen are the same poor photocopy in PDF format. The Google the SED1335, since it's compatible, is a good clean copy.
/*Update*/ Core library working.
Operating voltage is 5 volts
The sheet states adjustable -25 volts for the LCD bias voltage, I found that about -10.52 ish produces the right contrast on the display. Built a cheep Switching negative power supply i found on the internet that gives up to -14. Will post schematic.
The LCD uses a 8-bit parallel interface as stated compatible with the 8080/Z80 bus. 5 control lines all come off the main 17 pin connector marked J2 on the board.
Frame ground
Vss (ground)
Vdd +5
Vo LCD negative bias voltage Spec says up to -20. (about -10.52 seems to be best so a negative supply source -12 to -15 would work )
/RES active low Reset signal
/RD active low Read LCD
/WR active low Write LCD
/CS Chip select active low
A0 Write Data Low/High Write command (if using directly to bus use CPU address pin zero)
DB0 Data lines
DB1
DB2
DB3
DB4
DB5
DB6
DB7
This LCD is 8080/Z80 bus compatible can be connected directly to the system bus.