RE: Lunar Lander Test Mode? Anyone?

> I'll check my Lunar Lander tonight.
>
(Thanks! To everybody-- very curious to track this down!)

> Clay, what kind of hack will be required to read the analog input
> (thrust)
> on an asteroids board?
>
I've got two options I've been kicking around:

1) add a modern 8-bit A/D to the daughterboard and let the user decide
what they want to hook up to it. (I think I'll leave this as an option
at purchase time-- probably a $5-10 option.)

2) Use thrust and fire. My thought was to just use a little PIC or AVR
to read those two buttons and present an 8-bit thrust value to the
appropriate register. Fire is "thrust value up", Thrust is "thrust
value down". "double-clicking" on Thrust instantly sets thrust to None,
"double-clicking" on Fire instantly sets thrust to Max. Hyperspace is
Abort. I think that would work OK, might need to have a little "count
slow when button first pressed, count fast when button held down more
than xxx mS" condition, but the AVR or PIC can handle that in it's
sleep...

> I remember comparing an asteroids board and a LL board several months
> ago
> and thought it shouldn't be too hard to hack an asteroids to run LL.
>
'Wouldn't be too hard' is relative. ;-) They're very close, but they
have some annoying differences. Most notably in the input and sound
areas. LL has a lot of stuff on a parallel read latch, where Asteroids
puts stuff on sequential addresses all reading bit 7. The memory map is
a little differnt, but that's an easy fix. Sound is pretty boogered up
too.

Based on past experience I wanted something that installs as easily as
possible and is easily reversable, and I'm willing to spend software
time to reduce the mods to the main board. I decided that unplugging
the CPU and Vector ROM would be the easiest for most people, so that's
what I'm after-- unplug CPU and VROM, plug in daughtercards. I'll have
about 2-3 wires that need to get soldered to the board (pick up one
select line from the Vector Generator and bring the POKEY sound down to
the main sound section.)

The rest is software patches, which haven't been too bad so far, but
also aren't working yet. :-( I've got about 200 bytes of patches so far
which accounts for the inputs on 2000 and 2400 selects (I thought).
Still have to do sound on top of that.

Since there are sooooo many different board versions of Asteroids I
don't want to have 6 different instruction manuals for each particular
install. (And documenting a "if your board does *not* have 74399's by
the vector section, but *does* have 7497's in the 8 row of chips, then
go to IC L11 and...." would be pretty horrid...)

-Clay
Received on Wed Feb 17 15:57:07 1999