Help resolving STE Booster instability?

[Maeke]

Yeah, I was reading, I take it that was a late model STE with no socket?

That's exactly that.

[IngoQ]

Hiya,

SIMMs arrived, tried them out, no change

Only other thing is to make sure P100 resistor pack is 1.2K. Its near the front of the CPU/Blitter somewhere.

If I interpret M9-1-122J correctly, it is 9 pin, bussed, 1.2k with 5% tolerance.

When I have some spare time, I will recheck the soldering connections and see if 16MHz improves anything.

But I guess, the socket construction simply is crap and I will have to rethink my strategy

[exxos]

But I guess, the socket construction simply is crap and I will have to rethink my strategy

It doesn't take much to push the STE over the edge. A slight bit of noise in the wrong place and total chaos. Its why it takes me so long to debug boosters, its more like 1 day to design the things, then 6 months tracing why the thing isn't stable. Its even worse on the STFM .

[IngoQ]

Yep. And it sucks even more, when you have no scope. But I just sold a refurbished Amiga 500 for 210 EUR, so I guess next month I will be able to order my Rigol DS1054Z.

I guess it will not make much sense to continue searching for the cause, until I have the proper equipment. At least today my desoldering station arrived... a chinese cheapo, but I guess better than 2 km of solder wick

[IngoQ]

Damn it... I confused GND and VCC on the booster board, and managed to kill the CPU and probably the GAL...

When replacing the CPU with the original one, it still wouldn't work, I had to reconnect the original CPU clock, then the system booted again. So I guess the CPU is definately gone, and the GAL and/or more components on the booster PCB as well.

So I need replacement, but what do I do?

For hacking into the machine, the 1.5 Booster seems a simpler choice, but can it do 32MHz?

And of course, I will need a new MC68HC000...

[exxos]

For hacking into the machine, the 1.5 Booster seems a simpler choice, but can it do 32MHz?

I ran it at 32mhz for the "prototype" for the STE V1 booster. Though I only tried it on that one machine, while it works, I cannot say if it would work on any other machines without issues.. So you probably would be better hacking in the proper STE booster.. I can send you a new CPU & GAL if needs be..

[IngoQ]

FINALLY!

With Exxos help I managed to successfully push my STE to 32MHz... and not only by using the STE Booster, but it works with the 1.5 Booster as well

Now I'll do a write up in the Member Blog section for others to scare off

[exxos]

FINALLY!

With Exxos help I managed to successfully push my STE to 32MHz... and not only by using the STE Booster, but it works with the 1.5 Booster as well

Now I'll do a write up in the Member Blog section for others to scare off

Congrats!

You may need to tweak some resistors if using V1.5 and you have stability issues.

[IngoQ]

You may need to tweak some resistors if using V1.5 and you have stability issues.

I had it run GB6 loops for a couple of hours (100+ iterations) and had not a single crash, so I am quite positive But I will do some more testing.

[IngoQ]

See the follow-up here, where I describe it in detail:

https://www.exxosforum.co.uk/forum/viewt ... f=18&t=358