From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <1439606969.39241.YahooMailBasic@web184704.mail.ne1.yahoo.com> References: <487AA177-7034-41C3-A747-31D8E7BBF1EB@quintile.net> <1439606969.39241.YahooMailBasic@web184704.mail.ne1.yahoo.com> Date: Sat, 15 Aug 2015 09:28:56 -0400 Message-ID: From: Joseph Stewart To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary=001a1140f16eeac9b4051d598cfb Subject: Re: [9fans] Small Plan 9 Platforms Topicbox-Message-UUID: 66e1d136-ead9-11e9-9d60-3106f5b1d025 --001a1140f16eeac9b4051d598cfb Content-Type: text/plain; charset=UTF-8 Brian, does your uni let you publish your curriculum or course notes? Is this something you've ever considered? -joe On Fri, Aug 14, 2015 at 10:49 PM, Brian L. Stuart wrote: > > I have tried to email BLS but fear I am being spam filtered... you there? > > I did get one message from you, and replied earlier today. Hopefully > it got through. > > A little more update on recent pi playing. I've been working on a > little toy the last few days, namely one of those small SPI driven > LCD panels: > > http://www.adafruit.com/products/2441 > > As of this evening, I've gotten it sort of running alongside the > HDMI display showing the upper left corner. Here are a few > pics of it in operation: > > The Pi with the display connected to a keyboard and mouse: > > http://cs.drexel.edu/~bls96/9pitft1-s.jpg > > and a couple of pics of the display showing acme running: > > http://cs.drexel.edu/~bls96/9pitft2-s.jpg > http://cs.drexel.edu/~bls96/9pitft3-s.jpg > > It's a long way from being usable though. The fundamental issue > is that there appears to be a very deeply embedded assumption > that a screen must be memory mapped. I tried hooking into > the hwdraw() routine in screen.c, but it seems that not every > change to the screen memory space gets reflected in a call > to hwdraw(). For the pics, I've got a version that periodically > copies the whole of the appropriate area of the Memimage > to the LCD panel over the SPI port. Obviously, that's too slow > and too resource-hungry to be practical. Hopefully, I'm missing > something and there's an elegant way to graft a non-memory > mapped display into the devdraw/memdraw/screen infrastructure. > > BLS > > > --001a1140f16eeac9b4051d598cfb Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
=C2=A0
Brian, does your uni let you publish your c= urriculum or course notes? Is this something you've ever considered?
-joe

= On Fri, Aug 14, 2015 at 10:49 PM, Brian L. Stuart <blstuart@bellsouth= .net> wrote:
> I have tried to email BLS but fear I am being spam filtered... you = there?

I did get one message from you, and replied earlier today.=C2=A0 Hop= efully
it got through.

A little more update on recent pi playing.=C2=A0 I've been working on a=
little toy the last few days, namely one of those small SPI driven
LCD panels:

http://www.adafruit.com/products/2441

As of this evening, I've gotten it sort of running alongside the
HDMI display showing the upper left corner.=C2=A0 Here are a few
pics of it in operation:

The Pi with the display connected to a keyboard and mouse:

http://cs.drexel.edu/~bls96/9pitft1-s.jpg

and a couple of pics of the display showing acme running:

http://cs.drexel.edu/~bls96/9pitft2-s.jpg
http://cs.drexel.edu/~bls96/9pitft3-s.jpg

It's a long way from being usable though.=C2=A0 The fundamental issue is that there appears to be a very deeply embedded assumption
that a screen must be memory mapped.=C2=A0 I tried hooking into
the hwdraw() routine in screen.c, but it seems that not every
change to the screen memory space gets reflected in a call
to hwdraw().=C2=A0 For the pics, I've got a version that periodically copies the whole of the appropriate area of the Memimage
to the LCD panel over the SPI port.=C2=A0 Obviously, that's too slow and too resource-hungry to be practical.=C2=A0 Hopefully, I'm missing something and there's an elegant way to graft a non-memory
mapped display into the devdraw/memdraw/screen infrastructure.

BLS



--001a1140f16eeac9b4051d598cfb--