[openfirmware] Some word not in ofw.c32 ?

Mitch Bradley wmb at laptop.org
Tue May 24 03:54:08 CEST 2011

Look at http://wiki.laptop.org/go/Forth_Lessons

The first few lessons are basic Forth, then around lesson 9 it starts to 
talk about Open Firmware specifics.

Open Firmware device drivers are object oriented.  Before you can use 
them, you must select the "instance" of the object that you wish to use. 
  The reason for this complexity is so that you can use the same device 
driver for multiple instances of a device - for example you might have 
two different disks that use the same driver.

The terminal emulator package is used by the screen object, so you must 
select the screen context before you can use terminal emulator methods. 
  The "stdout" variable contains a pointer to an already-open screen 
object, so you can select it by writing

ok stdout @ iselect

After you do that, you can write, for example:

ok foreground-color .
ok 2 to foreground-color

which should change the text color to green.

On 5/23/2011 3:01 PM, 胡松涛 wrote:
> Hi,
> I want to write some application when I go into the interpreter, I
> follow these tutorial:
> http://www.openfirmware.org/1275/practice/
> But when I learn the first one: 16 Color Text Extension, I met problem.
> I want to have a try on foreground-color, but it seemed can't run and
> returned some information:
> ok foreground-color
> Tried to access instance-specific data with no current instance
> ok
> I have this one on my laptop
> /packages/terminal-emulator
> Did I miss some thing when I read the documents?
> I'm pretty new with Open Firmware, are there easier tutorial for beginners?
> references:
> http://www.openfirmware.org/1275/practice/
> http://www.openfirmware.org/1275/proposals/index.html

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