330 disable function bug

[alenppc]

Some people have observed that the disable function does not work correctly. I have already spoken with Stephen about this, but I thought I'd post for the rest who may not know about this yet.

Basically, the disable function (when the jumper is removed) will fail intermittently. On certain occasions, the console will boot in 68020 mode but crash shortly after as the 68030 unexpectedly comes to life (it will get quite hot quickly).
In other occasions, both CPUs will become active at powerup, even if the jumper is removed.

I have been able to reproduce this consistently with multiple cards. I am not sure what causes it, but Stephen has devised a tentative fix that involves adding resistors. I haven't had the chance to test it yet though.

[terriblefire]

I think this is caused by a floating pin. I’ve put a big pull down on the latest TF330 order.

[alenppc]

Tested the hardware fix today, but the 68030 still comes to life after a few minutes.

[terriblefire]

Tested the hardware fix today, but the 68030 still comes to life after a few minutes.

I will try and come up with a firmware update to latch the DISABLE state on reset.

[8 Bit Dreams]

Ok,
Can confirm, disable function isn't working properly, 030 gets very hot, black or green screen

[terriblefire]

I havent tested this one but if anyone wants to try out my firmware fix for the reset bug here it is..

tf330_2019_05_24_alpha.zip

[alenppc]

I am getting no change in behaviour... both with the hw fixed and the regular cards... Can anyone else try this?

[supaduper]

Already have and reported the same as you to Steve yesterday

[theq]

With disable function you mean removing the jumper that makes this thing tick?
If so, how would I see if the 330 suddenly starts ticking again, by a hang/restart?

Reason why I'm asking is that I have removed the jumper and played one (1) game (Cannon Fodder) continuously for 1,5 hours without any problems. Didn't reset or try any other games with the power on, though.

And, mind me for asking, why have a disable "switch" anyhow? The other expansions like SX-32 don't have it. You would just remove the card to revert to vanilla state.

[terriblefire]

Its to save wear on the edge connectors.

The disable function doesnt just stop the thing "ticking" it switches from holding the 020 inactive to holding the 030 inactive. My guess is some noise is causing an issue.