3 Oct
1999
3 Oct
'99
9:17 a.m.
By the way, I am curious where you got your lander
program... I ask
because a few years back, I contacted Jack (via a pointer from the
Computer Museum in Boston), and what he had was a 9 -Track tape that he
had gotten from someone who had preserved a copy while he was at the
University of Wisconsin-Milwaukee. He sent me the tape, and I read it
and returned the contents to him, including the lander program, some demo
programs, etc.
The version I have is the one I obtained back in 1975 or so... one
that Jack and I worked on when I was a student at WPI and he was
visiting the college for some reason... The ME department had a
GT44 (11/40 based system with a VT11 and VR14) and we did some work
on it to fix some intensity problems with the thrust and directional
control bars as well as getting it to work with a programmable clock.
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
3 Oct
3 Oct
8:43 p.m.
Megan wrote about GT40 Moonlander:
The version I have is the one I obtained back in 1975
or so... one
that Jack and I worked on when I was a student at WPI and he was
visiting the college for some reason... The ME department had a
GT44 (11/40 based system with a VT11 and VR14) and we did some work
on it to fix some intensity problems with the thrust and directional
control bars as well as getting it to work with a programmable clock.
Is it intentional that the minimum thrust setting is 10%?
After the game ran correctly for about six hours, it lost the thrust
indicator (the little horizontal line with a two-digit percentage right
next to the thrust control bar). It was still possible to control the
thrust. After another half hour, the display stopped working entirely,
although from the keyboard beeping on crashes, it was obvious that the
game was still running. I surmise that the display list was getting
corrupted.
Since my GT40 does not have the standard GT40 boot ROMs, it takes me a
long time to toggle in a reassembled version of the standard ROMs,
reorigined to run at 037000, and then load the program. I was annoyed
to find that Moonlander overwrites the memory from 037000 to 037777, so
I guess that wasn't the best choice on my part.
If I'd had time to do it, it would have made sense to ask someone for a
copy of the RIM loader and a description of RIM format, and use that
instead, since it would require much less time to toggle in, and be less
error prone.
I suppose that I should mention that Mike Cheponis and I won the VCF
First Place award in the Minicomputer category for our GT40 exhibit. It
was rumored that Jack Burness might attend the VCF, but AFAIK he didn't.
Cheers,
Eric
4 Oct
4 Oct
11:51 a.m.
Is it intentional that the minimum thrust setting is
10%?
I'm afraid I can't answer that... only Jack can.
I seem to remember that with that setting, if nothing else is
changed, you get pretty close (though you have to do 100% thrust
for a few seconds...)
After the game ran correctly for about six hours, it
lost the thrust
indicator (the little horizontal line with a two-digit percentage right
next to the thrust control bar). It was still possible to control the
thrust. After another half hour, the display stopped working entirely,
although from the keyboard beeping on crashes, it was obvious that the
game was still running. I surmise that the display list was getting
corrupted.
That is possible... each crash extends the display list because of the
wreckage. But I'm not sure. I have seen the unit run for MANY hours
without crashing or even losing any of the display... I guess it may
have to do with how much memory you have.
A few tricks...
o I'm sure you know about flying through the mountain, so
I won't mention it here.
o Same for the trick of flying up over the mountain and
landing on the other side... I think these have both been
documented
o If the lander lands successfully within range of the
McD's, it sets the amount of fuel to be a constant for
the take-off. You can land again if you are fast on
reducing the amount of thrust.
o The amount of fuel left is kept in location 130 or 140
(if I remember correctly). If you run out of fuel, it
is possible to halt the machine and fuel-up :-)
If I'd had time to do it, it would have made sense
to ask someone for a
copy of the RIM loader and a description of RIM format, and use that
instead, since it would require much less time to toggle in, and be less
error prone.
Or take out the extra serial interface and put in an RX11 and attach
it to a desktop RX01... My first contact with a GT40 was in such a
configuration... running RT-11 (1975)
I suppose that I should mention that Mike Cheponis and
I won the VCF
First Place award in the Minicomputer category for our GT40 exhibit. It
was rumored that Jack Burness might attend the VCF, but AFAIK he didn't.
Congrats!
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
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