MC68(xx)030RP(xxx) variants? What to get, and what to avoid?

[alenppc]

68030RP33Bs seem to have come out later in the game, around 93-96 from what I can tell from pictures, years after the initial 030s? Did these plastic green-bottom/black-top PGA ones still have different masks by that point? I.e., does anyone have 68030RP33Bs that they know to be genuine 33Mhz rated but still do not work at 50Mhz?

Yes, I have ton of those. As others said, it's a lottery. Sometimes you will find 25 mhz rated chips that work great at 50. Sometimes you'll find 40 mhz rated ones that won't boot at 50.

[richx]

Thanks for confirming, was hoping genuine ones had a better rate.

[alenppc]

1995 was truly a terrible year for Motorola. None of these CPUs will run at 50 mhz. Some will boot but crash soon after. Some won't even boot. Of course they would be ideal for 40 mhz but nobody wants a 40 mhz accelerator. Virtually all of those made in '93 are fine however.

IMG_1206.jpg

[exxos]

I've said it before, I can get legitimately sourced CPUs, but unfortunately the price for these is lot higher than China.. But my supply chain are not fakes or copies, they are basically direct from manufacturer.. I can't of course say how well any of these will over clock as I have never used these CPUs personally.

These prices I assume are still current, but this was from several months ago.

Overseas stock
MC68EC030RP40B - ~£30
MC68EC030RP40C - ~£30
MC68030RC50C – ~ £60

These are direct from the manufacturer and UK stock.
MC68EC030RP40C £60

Various date codes
0103 x 14pcs, 0019 x 14pcs, 9712 x 38pcs, 0006 x 46pcs, 0030 x 8pcs, 9933 x 67pcs,0034 x 126pcs, 9719 x 5pcs, 9827 x 14pcs, 9838 x 42pcs, 9834 x 151pcs.

[alenppc]

Exxos, I think you missed the point of my post. This was more as an example after someone asked the other day if the 68030RP33 was going to work in Stephen’s board.

I built many of those and I definitely can’t afford to buy CPUs from official resellers because then the final board would cost a lot more than it does now and that would make people very unhappy.

In the example pic above, while it’s true that there are some reprints, the vast majority is genuine. I was trying to point out what people can expect. If you buy 40 cpus and the box contains a sea of ‘95 date codes, expect very few of those, if any, to run at 50 MHz. That was definitely the worst year.

‘93 meanwhile was a great year and almost all of those will run at 50 without breaking a sweat. Things got only marginally better in ‘96 and slowly improved later on. This is obviously assuming that you get genuine parts and not reprints.

So even if I only get about 30% of CPUs In a given batch to run at 50 MHz, it’s still way cheaper than getting 50 MHz parts from official resellers even with the duds factored in the final board cost.

Anyway, the stash pictured above are all the duds that I collected over time, a sea of ‘95 date codes.

This is also to answer those who get one of my boards and ask if they should replace the cpu I provided with their own: there is no point. I already tested the heck out of the one I sent you. Yours may not be as good.

[8 Bit Dreams]

@alenppc is your camera also buit in '95, or did You used a potato to take that pic? :lol: :lol: :lol:

Seriously, you can be lucky if RP33 works @50Mhz, had also 100 of them but to be fair very few of them completed 24h soak test, i think if these were able to run stable @40Mhz Motorola would label them as RP40, but no, these are 33 and that's it. Period

[alenppc]

@alenppc is your camera also buit in '95, or did You used a potato to take that pic? :lol: :lol: :lol:

Seriously, you can be lucky if RP33 works @50Mhz, had also 100 of them but to be fair very few of them completed 24h soak test, i think if these were able to run stable @40Mhz Motorola would label them as RP40, but no, these are 33 and that's it. Period

Nah, try '93 date codes, it will work fine.

[richx]

There was a post (https://www.exxosforum.co.uk/forum/viewt ... =70#p25639) last year where some CPUs worked on other accelerators but had issues on the TFs. Not sure if still applicable or if there was any conclusion, should be opposite with the dynamic clocking.

The “new” and shiny 50MHz ceramic ones on eBay don’t seem to have any vertical markings. Not sure if it’s because those were repainted or some revisions just didn’t have the vertical markings. Bought some supposedly genuine (used) ceramic 50MHz MC68030RC50Cs, curious how those will turn out.

[8 Bit Dreams]

There was a post (https://www.exxosforum.co.uk/forum/viewt ... =70#p25639) last year where some CPUs worked on other accelerators but had issues on the TFs. Not sure if still applicable or if there was any conclusion, should be opposite with the dynamic clocking.

The “new” and shiny 50MHz ceramic ones on eBay don’t seem to have any vertical markings. Not sure if it’s because those were repainted or some revisions just didn’t have the vertical markings. Bought some supposedly genuine (used) ceramic 50MHz MC68030RC50Cs, curious how those will turn out.

@richx
Thanks for pointing this out bud, of course i sharing this information cause i don't want people make same mistakes i did..

Curious why some RP33B CPUs are not working @50Mhz? Well.. Maybe because of this?

IMG-20200718-WA0031.jpg

Yes, your eyes dont lie, these are 25Mhz that was relabeled to 33Mhz and shoud run @50Mhz...Well.. good luck..