Vectron - No More Enemies!

[Zendocon]

I had posted this to the thread about hacking Night Stalker, but it deserves its own thread. That and I have more information here.

 

How would you like to play Vectron with all the Nasties disabled? It's easy to do! The only drawback to this is that 2-player mode is disabled, which is fine because the only time the other player takes control is when you lose an Energy Block, and that can now only happen by running out of energy.

 

If you have the .bin+.cfg files, then make a copy of these files and call them veccheat, and append this text to the veccheat.cfg file:

__________

 

[macro]

@p 55ed 2b8

@p 55ee 4

@p 55ef 240

@p 55f0 104

__________

 

If you have the .rom file, then you'll have to create a file which we'll call veccheat.txt

 

Enter this text into that file:

__________

 

p 55ed 2b8

p 55ee 4

p 55ef 240

p 55f0 104

r

__________

 

The above file is a script for the jzintv debugger. To run it, launch jzintv with these switches:

--debugger

--script=veccheat.txt

 

I tried it both ways with the different ROM file types, and both methods work for me.

 

In either case, you'll probably also want a keyboard "hack file" to bind the "southern hemisphere" of the disc to something like ZXCVBNM, and the action keys to the left, up, and right arrows. We'll create a file called veckeys.cfg with this text in it:

__________

 

map 0

 

1 PD0L_KP1

2 PD0L_KP2

3 PD0L_KP3

4 PD0L_KP4

5 PD0L_KP5

6 PD0L_KP6

7 PD0L_KP7

8 PD0L_KP8

9 PD0L_KP9

0 PD0L_KP0

 

UP PD0L_A_T

LEFT PD0L_A_L

RIGHT PD0L_A_R

 

Z PD0L_J_WSW

X PD0L_J_SW

C PD0L_J_SSW

V PD0L_J_S

B PD0L_J_SSE

N PD0L_J_SE

M PD0L_J_ESE

__________

 

Note: those are zeroes everywhere you see "PD0L". Also, I enabled all the numeric keypad keys so you can still activate the Easter Egg.

 

To enable these key bindings, launch jzintv with this switch (in addition to the other two):

--kbdhackfile=veckeys.cfg

 

With all that typing you'd have to do, it's best if you wrap all that up into a Batch File. But it's worth it to see what lies beyond Level 16, and to play through all 99 levels unhindered, or to try to activate the Easter Egg yourself.

 

Let me know if I missed anything or if something needs to be corrected. I'm off now to see what else we can put in here for fun, like a different starting level or lots of points.

 

Vengeance is thine!

[Zendocon]

Here's some more fun to add to the .txt file if you're using a .rom file. (If you're modifying a .cfg file, just preface each line with '@' as before.)

__________

 

p 55ec 164 ; Lots of points at start - higher "number of players" means more points

p 664d 2b9 ; After Level 1 ...

p 664e 62 ; go straight to "Level 99"

p 6808 ff ; Easter egg doesn't care ...

p 6809 204 ; what level we just completed

p 680c 204 ; Easter egg doesn't care what key you press to start next level

p 6811 204 ; Easter egg doesn't care about the last position of the Energy Block

p 6817 204 ; Easter egg doesn't care what happened on previous levels

p 681d 20e ; Easter egg doesn't care how many players you entered at start

__________

 

So let's try it out.

 

Enter '9' at the "number of players" screen and you should start with over 23 million points.

 

After Level 1, you should continue to "level 99" and you should see the Easter Egg message.

 

"Level 99" still gives us the base shape for Level 2 (normally would be Level 9). The E-Paks take longer to arrive now. The base is the same color as the background, much like the "Invisible Robot" in Night Stalker, so you can only see it where the Energy Block passes behind it.

 

Complete this level and see the endgame message. I'll see if I can somehow start the base at the shape for Level 17, so you can see the last two base shapes before finishing the game.

[Tempest]

Is it true that the game becomes unplayable past level 17? If so, how did the playtesters not catch that?

[Zendocon]

The Prizum levels (16-18) are normally impossible to beat. I had discovered that in 1999. Only one Prizum appears at a time (it uses all four "enemy sprites" to create a multicolored image), but it takes three shots to destroy one, and it homes in on your Energy Block. There is no way to destroy it before it reaches your base and starts to tear it down.

 

All the earlier stages eventually "time out," and past that point, the Nasties and E-Paks don't respawn anymore, leaving you to finish building the base unhindered with all the energy you have left. The Prizum stages don't "time out," and you can't destroy a Prizum fast enough. Therefore, they are impossible.

 

If you just disable the enemies, that's no longer an issue. You can play all the way through all 99 Levels.

[Zendocon]

Why the playtesters "never caught it" beats me. It could have been deliberate for all we know. I have an idea how that could be.

 

First, the box has a message "We dare you to make it past Level 10" or something like that. Second, the instruction manual mentions "the unlikely event that you complete all 99 Levels."

Third, the story behind the game was that it was created to counter the Intellivision's competitive disadvantage (no arcade conversions, unlike Atari) by having games that would later be ported to arcade games. Perhaps there would have been a future peripheral that would provide a "hardware patch" when Vectron was connected to it, to make it playable. That's just a guess though.

 

Vectron ended up being the only game in Mattel's "Arcade Network," because they then struck a deal with Data East and released a few arcade titles, plus Konami's Locomotion.

[+fdr4prez]

Or directly go to level 99 by using this rom here: http://spatula-city.org/~im14u2c/intv/dl/vectron99.rom

[Zendocon]

I did that originally, set the starting stage to 99, but then I decided to do it this way so people could see the easter egg as well. You can't see the Easter Egg message after you finish the game.

[Zendocon]

That ROM looks familiar. In Carl Mueller Jr.'s INTVPC, there were function keys for save scumming. The save scum file was just a dump of the whole 64K address range. From there, it was possible to patch it into a ROM image, and in this case, convert it to .ROM format as well.

 

I fired it up, and immediately went out to the debugger and entered these two commands:

 

p 104 4 ; Disable the Diamondbacks

p 164 26 ; Nearly max out the score

 

With that .txt file from earlier, the Easter Egg still activated, and that was all. I'm glad to know I didn't spend all those hours save scumming my way through 99 levels for nothing.

[intvnut]

Here's some more fun to add to the .txt file if you're using a .rom file. (If you're modifying a .cfg file, just preface each line with '@' as before.)

 

You don't need the @ symbol. That prevented INTVPC from printing the line in its debugger. In jzIntv, it doesn't really have any effect. Likewise for LTO Flash.