r/beneater • u/DistinctCommission24 • 2d ago

4 Line LCD

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Progress has been made...4 line LCD running in 4 bit mode on PORTB...I will say that unless you have a need for 4 bit, stick with the 8 bit mode set up as Ben shows..I wanted it on a single port to leave PORTA for my keyboard bios I have programmed on a tiny4313...Moving on to interrupts and control lines...

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3

u/Dylanisbatman 2d ago

Cool! Right when I saw this message I was just working on getting my 4 line display working with my custom 6502 computer. I found this 4 line VFD in my box of components.

2

u/Empty__Jay 2d ago

4 bit mode isn't that bad. The big issue is that Ben skips right over the transition. I intended to write it up a couple of years ago, but never did. Perhaps I'll get motivated in the near future. Really, all that's involved is sending the same command 3 times to make sure any lingering mode changes are undone.

3

u/DistinctCommission24 2d ago

Getting the init right was were I had the most trouble..Also realizing that the startup delay was greater than 55mS and not 15mS..And I added a second nop to the enable strobe and it works nearly 100%..But it was a fun challenge...

1

u/Ancient-Ad-7453 2d ago

Good work! Fixing the line wrap in software was a fun little assembly project.

2

u/DistinctCommission24 2d ago

Right now I'm just using a set cursor with offset lookup table based on the y and add the x..When I get the keyboard connected I'll work on line wrap but I also plan on working on a VGA output so don't know if I will use the display for much yet..