Adventure in Ersatz-11

From: Jerome Fine <jhfine_at_idirect.com>
Date: Tue Oct 23 17:40:39 2001

>Gooijen H wrote:

> Yes !!

Jerome Fine replies:

Thank you for the feed back. I was not sure how much memory
ADVENT requires. You might also try:
BOOT RT11SJ
if you wish.

> Thanks very much, Jerome.
> Booting RT-11FB and then running ADVENT still produces
> the "Insufficient memory" fatal error.
> However, VBGEXE works fine !
> After the "Welcome to Adventure!! Would you like instructions?"
> and entering 'YES", it goes: Somewhere nearby is Colossal Cave,
> etc.
> This means that I am now going to play Adventure. This has a
> serious drawback on the expansion of my website ...
> I am playing it on my "homebrew-PDP" with the BLINKENLIGHTS on!!
> On my website this project (early phase) has a separate link.
> BTW. What is VBGEXE, what do the letters stand for?
> Thanks again,
> Henk.

"EXEcute Virtual BackGround program" is how I think of the letters
with the understanding that the word EXEcute is then switched to the end.

A few points worth noting.

(a) If FOO.SAV requires any arguments as in:
"RUN DEV:FOO.SAV arguments" or replace RUN with VBGEXE,
then they must be on the same line. The alternative is the put all three
parts of the command on separate lines. Otherwise, with just
"VBGEXE DEV:FOO.SAV" on the first line, somehow the request
for information expects the arguments to already be there and if not,
just exits. Entering:
VBGEXE
DEV:FOO.SAV
arguments
on three separate lines works as well.

(b) The command:
SRUN VBGEXE.SAV/TERMINAL:n/LEVEL:m/NAME:utility
also works very well when you want to run a system job at a higher priority.
TERMINAL is only useful with a system that has multi-terminal support
LEVEL specifies the system job number ( 1=>6 )
NAME can be used to automatically select an executable file called SY:utility.SAV
One minor problem is that if name is omitted, then only ONE instance of
VBGEXE can be invoked as a system job since the high memory GRCBs (Global
Region Control Blocks) must all have different names. I have a small patch
with allows the user to do the command:
SRUN VBGEXE.SAV/TERMINAL:n/LEVEL:m/NAME:VBGEXm
If that is done, each GRCB is given the name VBGEXm making them all
different. This means that no program can have the name VBGEX(1=>6),
a restriction that I assume can be lived with.

I also remember that modifying TECO to be named VMUNG so that
"VBGEXE VMUNG arguments"
would work the same as
"MUNG arguments"
but use the full 64 KBytes allowed by VBGEXE.

By the way, I assume that you are using E11 on a PC. Which hardware
and how fast do you find that the code runs compared to any real PDP-11
hardware. Plus, I can't remember about the "BLINKENLIGHTS" - what
did you do to have those available?

Sincerely yours,

Jerome Fine
Received on Tue Oct 23 2001 - 17:40:39 BST