intellivision collision detection issues

[bradhig1]

In both Old School and Microsurgeon I run into collision detection issues. In Microsurgeon shots sometimes go through things I shoot at like Bacteria ,Tumors , and clogged arteries. In Old School the erasers don't always hit the bullies like the manual says ,but sometimes I go right through the bullies with nothing happening. Is this a problem with the Intellivision hardware itself?

[DZ-Jay]

Is this a problem with the Intellivision hardware itself?

No. On Microsurgeon, it's probably because the Exec (internal operating system used by old Mattel games) is flakey and the programmer may not have compensated well for it.

 

On Old School, it is a known issue in the code. The programmer has admitted that there are issues with the game, because it is based on older code he made while learning the platform. Elektronite changed the documentation to say something like "sometimes the bully is strong and will not be harmed by the erasers."

 

The Intellivision hand controllers do have some quirky behaviour, but this can be worked-around or compensated for -- unless they get damaged.

 

dZ.

[mr_me]

Yeah the Exec takes three frames to move objects, so fast moving objects can be a problem for Exec based games. And like Dzjay said, its a software problem not hardware as the Intellivision does have hardware collision detection; and Intellivision games don't have to use the 20hz exec system. Flakey controllers can cause input problems but shouldn't affect collision detection.

 

Third party games like Imagic's Microsurgeon aren't suppose to use the Exec framework. But some Imagic games seem like they do, more so than Activision or Atarisoft games. Is there any evidence of third party games using the Exec framework?

Edited August 11, 2017 by mr_me

[Carl Mueller Jr]

No. On Microsurgeon, it's probably because the Exec (internal operating system used by old Mattel games) is flakey and the programmer may not have compensated well for it.

 

On Old School, it is a known issue in the code. The programmer has admitted that there are issues with the game, because it is based on older code he made while learning the platform. Elektronite changed the documentation to say something like "sometimes the bully is strong and will not be harmed by the erasers."

 

The Intellivision hand controllers do have some quirky behaviour, but this can be worked-around or compensated for -- unless they get damaged.

 

dZ.

Microsurgeon does not use the EXEC except to read the hand controls. Even if it did, collision detection isn't a problem with the EXEC because the hardware will record all collisions and set latches so that interactions, even if they occurred a few frames before will not be missed.

If the object has changed its internal ROM database pointer between the time the hardware recorded the interaction and the time the EXEC gets around to dispatching, you will miss the collision however.

I don't know what's going on with Microsurgeon, but I've known since I was a kid that it was very particular with where you shot the background.

Anyway, it's definitely not the hardware.

[DZ-Jay]

Dupe - removed.

[DZ-Jay]

Microsurgeon does not use the EXEC except to read the hand controls. Even if it did, collision detection isn't a problem with the EXEC because the hardware will record all collisions and set latches so that interactions, even if they occurred a few frames before will not be missed.

 

If the object has changed its internal ROM database pointer between the time the hardware recorded the interaction and the time the EXEC gets around to dispatching, you will miss the collision however.

 

I don't know what's going on with Microsurgeon, but I've known since I was a kid that it was very particular with where you shot the background.

 

Anyway, it's definitely not the hardware.

You are right that Imagic games like Microsurgeon do not use the EXEC, but that is beside the point. The question was if the collision issues were due to hardware flaws in the Intellvision and the answer is, no.

 

Microsurgeon does have some issues with responsiveness and accuracy, but those are due to program flaws or quirks of the game design. The same with Old School in a more pronounced way.

[Carl Mueller Jr]

You are right that Imagic games like Microsurgeon do not use the EXEC, but that is beside the point. The question was if the collision issues were due to hardware flaws in the Intellvision and the answer is, no.

 

Microsurgeon does have some issues with responsiveness and accuracy, but those are due to program flaws or quirks of the game design. The same with Old School in a more pronounced way.

I don't think it's beside the point when you're trying to assess how a game's collision detection is handled and you incorrectly report that it's flakiness is due to the EXEC, an operating system that it does not actually use.

And actually, there are hardware flaws in the Intellivision. For example, moving object #1 will not collide with the screen border.

[nanochess]

I've found the collision to be pretty exact in real Intellivision hardware, I think any problem is more software related or mishandling in read.