From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <304bae18668f389aae7eccd289462cda@quintile.net>
From: "Steve Simon" <steve@quintile.net>
Date: Wed,  6 May 2015 10:52:30 +0100
To: 9fans@9fans.net
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Subject: [9fans] small VFD display
Topicbox-Message-UUID: 4fa871e6-ead9-11e9-9d60-3106f5b1d025

Hi,

I want to drive a small (180x32 pixel) VFD display from plan9.
It talks i2c and can be driven as a text or graphics device.
One irritation is it aligns bitmap bytes verticaly. i.e. the display's
memory map appears to be a tradational 32x180 pixel display.

I am going to talk to this from a raspberry pi.

I see several options:

	resurect a small graphics library I wrote in the last milenimum, this
	knows about the weird layout but only supports rather nasty fonts and
	very simple windowing.

	talk text only to the display - again rather nasty fonts.

	draw the images in a plan9 window under rio. A seperate process
	which reads /dev/wsys/n/window, transforms it and sends it to the VFD.
	I would also need a backing buffer in VFD layout so only the changed
	bytes are sent.

Is there another way?

Could I run the plan9 graphics subsystem in a stand alone app rather
than involving the kernel?
I think I can but are there any examples of this?
Though this sounds nice, is it worth the hassle of doing this?

Any opinions?

-Steve