exxos's Atari, Amiga & retro forum

exxos wrote: 07 Apr 2021 22:33

terriblefire wrote: 07 Apr 2021 22:25 Nutcase.. :D

You still love me though :lol: :fire: :fire: :fire:

Well your the only one who'll let me lose on their forum.... mwhaahahahhaha,,,

Great work @exxos

Nice! :thumbup:

terriblefire wrote: 07 Apr 2021 22:25

exxos wrote: 07 Apr 2021 22:23 117.6MHz clock (58.8Mhz CPU)

Nutcase.. :D

Certifiable. :crazy:

BW

It looks like something really starts to struggle over 61Mhz. I have disabled the SDRAM as well.. I think it could just be the bus isolators.. I mean they take 20ns to disable... along with the ROM it is mostly moaning the ROM is having problems being accessed, and I have slowed its access right down as well. I put the plastic package one in which otherwise is working fine at 50 MHz, that one does not even boot up, so I assume it is the CPU actually tripping up and nothing else.

I am going to put a faster buffer on the next revision of the board. It is hard to find one that JLC stock , which are actually faster as well.

Yeah i never got 030s past 56-57Mhz without parts of them stopping to work. Think there is a fundamental limit somewhere there.

S

terriblefire wrote: 08 Apr 2021 13:01 Yeah i never got 030s past 56-57Mhz without parts of them stopping to work. Think there is a fundamental limit somewhere there.

In terms of long-term stability 50Mhz seems to be about as high as you could really go anyway. I have ordered a couple of supposed different mask EC's to see if they are any different.

Been busy rerouting the buffer isolator chips... It went from two chips to one chip, the fastest one I can really find is a ABT version. About 7ns isolation time, the old ones were about 20ns.

Feking Eagle libs :pullhair: :headbang: :cussing: :cussing:

Some time later... hope it fits this time...



EDIT:

Yep!

The board was running most of yesterday at 50MHz on my H4...



The results I was keeping a eye on.. The GEM dialog box ( actually that should probably be spelt dialogue ? :lol: ) It was interesting because in the morning the test was 300%.. And during the day when it all heated up in my room picked actually dropped to 299%.. And around midnight when it had dropped in temperature it went back up to 300% again! just goes to show how very small tolerances in hardware can affect things.