BBC LCD Interface

MDFS::Info.Comp.BBC.LCD

These are some pictures of an EPSON EA-Y40040AT (PN-A0019) 40x4 character LCD display I bought from a surplus electronics supplier in 1991 - I think it was Greenweld. I believe it uses two Hitachi HD44780 clones, EPSON's SED1300.


LCD and 1MHz interface	Close-up of the LCD

It was easy to interface to the BBC. I just needed a few NOT gates to toggle some select lines. The rest just connected straight to the 1MHz bus and to the +5v connector on the analogue port.

Unfortunately, I have't been able to get it working recently.

This is the information that came with it:

page01.txt 3K - Product outline (page01.gif 88K - scanned page)
page07.gif 66K - Device block diagram
page09.gif 116K - Electrical characteristics
page15.gif 47K - Example interfacing diagrams
page17.txt 2K - Pin connections, power and data (page17.gif 58K - scanned page)
page18.txt 3K - Pin connections, chip select and pinout (page18.gif 63K - scanned page)
page19.gif 58K - Pin connections, contrast adjustment
page21.txt 1K - Command instruction set (page21.gif 75K - scanned page)

Notes on connecting to a BBC:

notes1.gif 77K - Signal connections
notes2.gif 96K - Wiring diagram and header connectors
notes3.gif 101K - Header and IC wiring diagram
notes4.gif 32K - Command summary

I managed to find the following datasheets relevant to 40x4 LCDs:

dci404a.pdf 43K - Two-page overview from DCI.
ks0070b.pdf 567K - Fairly detailed information.
dci404a.gif 204K - I have a paper copy of one page of this, but cannot find the original file. If you find a copy, I'd welcome being sent a link to it.

Display/LCD - LCD tester and VDU link code
GregDisk06/LCD - Development MIDI sequencer that uses the LCD display

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Last update: 09-Jan-2005