13 May
2009
13 May
'09
4:40 a.m.
Good morning,
First, the BUILD.SV utility is both a tool to change
the OS
configuration and a record of the configuration. Typically, BUILD.SV
will contain the original configuration of the system. Changes are made
by RUNing and then SAVEing new versions of the configuration.
Yes, that's well
known on my side. It also seems to contain the LOADed device handlers.
The following is a transcript of taking a system
configuration saved in
BLDDMO.SV and adding a non-system TD8E handler. I will insert comments
with a #.
...
# in the configuration.
$BOOTSTRAP
SYS BUILT
That's pretty not what I wanted to do (gave up the idea running VT05 at >300 baud).
I know to use
BUILD. The point is elsewhere.
Thats all there is to it.
No. There is more.
There's ALWAYS more *g*
The console TTY is handled by the OS/8 keyboard handler *directly*. So it does NOT use one
of the
handlers installed with BUILD.
BUILD itself seems to contain the LOADed handlers. When you enter BOOT (or BOOTSTRAP),
BUILD writes
out OS/8 and the configured handlers to the specified system device. The specified system
device can
be clean before. That proves that BUILD really puts all the OS/8 stuff onto the
disk/DECTape.
How is the system INITIALLY built? There are *some* explanations in the OS/8 handbook,
involving
some obscure paper tapes and BUILD. But no really detailed description.
It would be nice to be able to compile OS/8 itself.
A TTY handler will already be present, so that will
have to be removed
before it can be replaced. DELETE removes the handler from the
configuration. UNLOAD completely deletes the handler from the BUILD image.
Yes,
yes, yes. BUT: The TTY handler is only responsible for the TTY: device used for things
like
DIRECT and other software using handlers.
The keyboard monitor does not use TTY:!
I gave up the idea patching the KBM to generate fill characters: a) I'm not sure if I
would be able
to insert even one instruction into the KBM code (it's written TIGHT!), b) There are
too many other
programs using direct I/O. They all would have to be patched as well (FORTRAN IV RTS as an
easy
example).
The OS/8 Handbook is your friend. Start at page 2-34.
Only at the first glance :-(
Best wishes,
Philipp
--
http://www.hachti.de