clock timing on 68030 processors

[TheBilgeRat]

I see different crystals for sale all the time for changing FPU and processor timing.  Are there specific processors (lets just look as the 030s) for specific speeds, or is it all just set by the crystal?  Is it as simple as pulling your 25 Mhz crystal for a 50?  Or does it depend on application (ie expansion card vs standard on the mobo)?

[Karlos]

As far as I know, 68030's were sold at 16, 20(?), 25, 33, 40 and 50MHz.

There wasn't a lot of overclocking room, some folks have got 50MHz parts to run at 60MHz I think. Trying to run a 25MHz 030 at 50MHz is not going to end well.

[TheBilgeRat]

But if you had both parts (50Mhz crystal, 50 Mhz '030) you could conceivably upgrade a processor on am expansion card?  Or are there other things which have to be factored in?

[strim]

But if you had both parts (50Mhz crystal, 50 Mhz '030) you could conceivably upgrade a processor on am expansion card?  Or are there other things which have to be factored in?

It depends on the turbo card, but in most cases other things must be factored. Like memory speed, logic chips speed, architectural problems. Some cards are certainly not upgradable this way, for example ACA series from Individual Computers, and some should work just fine as long as you got the right CPU, crystal and memory (most Blizzards).

[Karlos]

Other than the possible glue logic / memory speed issues mentioned above there's also the package type to consider. Slower 68030 tended to be PLCC, whereas the faster ones were usually PGA.

[TheBilgeRat]

So...moral of the story is do homework on an expansion card before purchase and if you want speed, spend the extra up front.

[Karlos]

So...moral of the story is do homework on an expansion card before purchase and if you want speed, spend the extra up front.

Something like that, though I am sure there is room for improvement if you had say a 25MHz card and a same-package 33MHz part and corresponding crystal. Unless the card had very sensitive timing, you should be able to replace it. That said, a lot of the slower 030's were also surface mounted, which might make replacement fiddly unless you are experienced with SMD.

[matthey]

@TheBilgeRat
Your homework should start at Dave's Hardware and Overclocking Page...

http://members.iinet.net.au/~davem2/amiga.html

[runequester]

As far as I know, 68030's were sold at 16, 20(?), 25, 33, 40 and 50MHz.

There wasn't a lot of overclocking room, some folks have got 50MHz parts to run at 60MHz I think. Trying to run a 25MHz 030 at 50MHz is not going to end well.

well, the ACA ones from individual computers run at 56, but apparently it took quite a bit of fiddling

[countzero]

if you're having funny thoughts about the recent ACA accelerators, you should read this ...

[TheBilgeRat]

I am trying to figure out the best way to get my A2000 a boost in speed.  I want to add the following soon to it when I get some play money (and listed by my current priority):

1.  Indivision ECS.  the monitor I got from runequester is starting to not hold brightness/contrast, so it would be nice for to have other viewing options.
2.  MiniMegi - who doesn't need 2M chip ram?
3.  Accelerator goes here, because otherwise:
4.  Can't use Deneb (AFAIK) on a stock 68000

I find the 030 accelerators in the 25Mhz range more frequently than the ones I would like.  Also there are a couple of designs to choose from (ones that plugin to the processor slot, ones that plug into a zorro slot etc.)

[countzero]

I find the 030 accelerators in the 25Mhz range more frequently than the ones I would like.  Also there are a couple of designs to choose from (ones that plugin to the processor slot, ones that plug into a zorro slot etc.)

You mean the processor SOCKET and processor SLOT. Processor slot is different to zorro slots. Technically a slot board and socket board are not superior to one another.

[TheBilgeRat]

You mean the processor SOCKET and processor SLOT. Processor slot is different to zorro slots. Technically a slot board and socket board are not superior to one another.

yes, exactly.  And that is good to know!

[shoggoth]

As far as I know, 68030's were sold at 16, 20(?), 25, 33, 40 and 50MHz.

There wasn't a lot of overclocking room, some folks have got 50MHz parts to run at 60MHz I think. Trying to run a 25MHz 030 at 50MHz is not going to end well.

33MHz pieces usually run very well at 50MHz (at least the PLCC package). That's a 50% increase. The 68882 is very overclockable, usually twice the rated clock speed is no problem at all.

[runequester]

I am trying to figure out the best way to get my A2000 a boost in speed.  I want to add the following soon to it when I get some play money (and listed by my current priority):

1.  Indivision ECS.  the monitor I got from runequester is starting to not hold brightness/contrast, so it would be nice for to have other viewing options.
2.  MiniMegi - who doesn't need 2M chip ram?
3.  Accelerator goes here, because otherwise:
4.  Can't use Deneb (AFAIK) on a stock 68000

I find the 030 accelerators in the 25Mhz range more frequently than the ones I would like.  Also there are a couple of designs to choose from (ones that plugin to the processor slot, ones that plug into a zorro slot etc.)

Depending on your end goals, an 030 is not a bad way to go at all. Very compatible software-wise and you can find them for less than a farm

Sad to hear about the monitor.
If you got a spare hundred bucks, this works great
http://www.ambery.com/rgbcgatovgac.html
though its not significantly cheaper than the Indivision ECS and those appear to still be in stock.

From what I gather, the indivision may give a sharper image than an external scan doubler, but I've also seen a fair number of people have a hard time with them.