[openfirmware] Some word not in ofw.c32 ?
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:
> I want to write some application when I go into the interpreter, I
> follow these tutorial:
> 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
> I have this one on my laptop
> Did I miss some thing when I read the documents?
> I'm pretty new with Open Firmware, are there easier tutorial for beginners?
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