CPU Strangeness

[rubber_jonnie]

Had a Mega ST2 back in the day, nice machine, would like to get another.

[PhilC]

I've got 3 at the moment. Upgrading it to 4mb over the week.

[rubber_jonnie]

Sweet.

Upgrading one of my dev boards to 1mb next week when I get the rest of the parts. All smt chips so will be interesting!

[PhilC]

Sweet.

Upgrading one of my dev boards to 1mb next week when I get the rest of the parts. All smt chips so will be interesting!

You'll do fine, the pitch of those chips should make it reasonably easy but then I would do it with hot air.

[rubber_jonnie]

Yeah the pitch does lend itself to hand soldering. I may use hot air, not decided yet.

[PhilC]

Don't forget to post the pics.

[rubber_jonnie]

Don't forget to post the pics.

Already got a post running for that 😁

[exxos]

But seriously, are there any revisions we should avoid and any that we should go look for?

70789 as RJ says. The silly style with cpu near the floppy seem worst. There's so many different versions I can't say they all are bad.. The similar boards with 4 ram chips under the PSU is assume are OK as well. They all kinda have their own quirks . 70789 are the boards I've had the least trouble with. Any revision if it generally seems OK.

[rubber_jonnie]

More strangeness, the C103253 now isn't working with its original CPU in a socket. Frankly bizarre as it was fine a couple of weeks back.

What's more weird, I removed the original CPU and plugged in my PAK68/2, and it fired up right away.

Now I know why Exxos has sleepless nights and all sorts of strange problems trying to get boosters working!

[PhilC]

Hi RJ,

Try putting some female headers on the CPU and then try it. Maybe the socket is getting a bit fussy about contacts. Have had this problem myself a couple of times