Phil C's Raven build

[PhilC]

I need to find a 100% working MC68150FN40...

I got mine from AliExpress believe it or not. They have grey text on them and not the white.

Here's the details of the shop I got it from and cost.

Screenshot_20250619-204022.png (180.28 KiB) Viewed 111 times

[luciodra]

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And these are the ones I ordered...I have problems with all of them

[PhilC]

Screenshot 2025-06-19 alle 23.55.49.png

And these are the ones I ordered...I have problems with all of them

Have you tried a slower main oscillator? Is the CPU definitely happy at 96mhz? I guess I've been lucky with my 68150 order.

Btw, try cleaning the pins of the 68150, I did that to all of mine and it helped.

[dml]

Not sure if it helps but I got the 7ns version from Mouser along with some of the connectors and also found a 10ns version from an eBay seller in Poland.

[luciodra]

Have you tried a slower main oscillator? Is the CPU definitely happy at 96mhz? I guess I've been lucky with my 68150 order.

Btw, try cleaning the pins of the 68150, I did that to all of mine and it helped.

I tried changing the socket without any improvements...
The system is now very stable at 96MHz with Picogus and network card using a small trick that I have already described...by patching the 16-bit part of the network card.

[agranlund]

Btw, try cleaning the pins of the 68150, I did that to all of mine and it helped.

I don't know if this anecdote is relevant (probably isn't) but my machine has started to develop an issue where it sometimes misbehaves when I start it after having sit for a while. Symptoms are no-start, or "random" issues then dies.

Pushing down on the ATF1508 and MC68150 plcc chips once makes the problem go away so I'm not in a rush to look into it -- it can wait until next time I take the board out of the case.

It should be said that my board has taken quite a bit of abuse in terms of flexing due to how often I swap ISA cards so I'm half suspecting I did a rushed and dodgy soldering job on one of them PLCC sockets.
Or maybe it's a matter of needing to clean pins on those IC's and their sockets.

I notice my Atari ST has metal clips securing plcc's firmly in their sockets and perhaps it's a good idea to find some of those too.

[PhilC]

@agranlund I've put heatsinks on both of those chips, only the small glue on types but if you think about it, running the 68150 at 48 is a 20% over lock, do it might also help?

[dml]

I have noticed that PLCC socketed ICs running above their rated frequency seem to be more prone to socket connection problems, resistance at the pins. e.g. taking the IC out and putting it back in can change the (bad) behaviour but the behaviour remains constant while its sitting there.

If the IC is not absolutely new, I have generally been brushing the IC pins with either fibreglass or steel bristle brush and then contact cleaner with a swab, before inserting.

I did look for those metal PLCC straps you mention - but wasn't lucky so far. There are 3 in my MegaST and those are the only ones I have.

[exxos]

So just for a bit of fun, here's the 96mhz gembench scores at 800x600x256 colours compared to a standard 8mhz STFM.PXL_20250618_133742997.jpg

I wonder if you can do one with caches turned off? I think GB6 will work with the 060 caches. If not, we can blame @dml for that one

[PhilC]

I've ordered the Eiffel patch board and the parts, so hopefully I should be able to get that done sometime soon.

If anyone from the UK wants one for their Raven then let me know.

I also ordered the ET4000 W32i PCBs from JLC, so will make up one of those too when I get time. Once again I've got a few spare, so will have those available for a donation. @agranlund I can send you one foc if you'd like?