Interest check.... 3D printed add ons for Intellivision controller....

[+DZ-Jay]

 

Thanks for that. So I guess you can't get the Intellivision to recognise a variable signal like the old PC analog joysticks without an extra processor. How about a spinner controller or a trackball that use quadrature? It's only two pins per axis. Maybe the Intellivision processor is too slow to calculate velocity.

You can calculate the velocity with the CPU, but in order for it to be stable, you will have to sync the sampling to the VBLANK interrupt; which caps your sampling rate at 60 Hz. In practice, I would imagine this to be sufficient.

 

However, the Intellivision is not really equipped to read analog signals. If you have an analog stick, you will have to digitize the signal.

[+intvsteve]

 

Thanks for that. So I guess you can't get the Intellivision to recognise a variable signal like the old PC analog joysticks without an extra processor. How about a spinner controller or a trackball that use quadrature? It's only two pins per axis. Maybe the Intellivision processor is too slow to calculate velocity.

Ah yeah- interesting notion to use quadrature! Been decades since I've done that sort of calculation. Ironically, back in the college days, I worked on a team project in which we built an ISA board (wire-wrapped! EDIT: and breadboarded!) for a PC that, instead of measuring quadrature ticks per sample period, did the opposite -- clock ticks per quadrature tick -- to try to get more accurate low-speed readings.

 

So it would really depend on how the ticks/revolution were set up, and whether, as DZ points out, a 60 Hz sample rate (or 50 Hz on PAL systems) would suffice.

Edited December 4, 2015 by intvsteve