Upgrading GVP A530 from EC030 @ 40MHz to Full 030 @ 50MHz

[Mogsy]

As the title says, I'm toying with the idea of replacing the 68030EC in my GVP A530 with a 68030RC50C 50MHz chip.

However, I just realized that I will probably need to replace the crystal as well...is this right?

Where on earth would I find one of those?

[roy bates]

there you go.


http://www.ebay.co.uk/itm/50Mhz-50-m...item3f1f840ac5

[Mogsy]

Thanks.

[Mogsy]

I take it any 50MHz one will do. I doesn't have to be a specific part code or manufacturer?

[roy bates]

nope,just has to be a 5 volt part.and in a 14 pin dil package.(you can use a 8 pin dil type but you will have to modify a 14 pin dil socket to accept it)
the one i linked to will be fine.

[Mogsy]

Great. Thanks.

[Mogsy]

Have ordered the crystal and also a 68030RC50 CPU. Can't wait!

I'll probably never have a use for the increased speed but nevermind.

[Damion]

You don't have to replace the crystal, the CPU will simply run at 40MHz. My advice would be to not overclock this particular card, the logic wasn't designed/rated for 50Mhz and there's a possibility of damage (as stated by one of designers anyway, you can still find his comments in the usenet archive if you dig a little).

[roy bates]

Originally Posted by Damion

You don't have to replace the crystal, the CPU will simply run at 40MHz. My advice would be to not overclock this particular card, the logic wasn't designed/rated for 50Mhz and there's a possibility of damage (as stated by one of designers anyway, you can still find his comments in the usenet archive if you dig a little).

they made one at 50mhz from the factory...

http://www.amiga-hardware.com/showha....cgi?HARDID=68


besides its not overclocked if they made them that way from stock.ive even had one of these at 50mhz it came that way even with an fpu.

[Damion]

OK, I dug it up...

Don't do it. You'll cook your PALs after a few weeks of operation... The 50mHz
boards were made with faster (and more expensive) PALs. We had to redesign our
casework (for airflow) to keep temperatures reasonable...We ran one without a fan
for an hour and melted the plastic insulation on the SCSI cable. If you want to try
it, go ahead... you might get lucky and have it work.
Erik Quackenbush
Systems Engineer
Scala, Inc.
(former GVP development staff)

and

Almost forgot- two more points:
1. Even if you don't have thermal problems, you will have RAM timing problems. At
50mHz you need to add a wait state to the RAM timing. This requires a PAL change.
If you don't add the wait state, you _might_ get lucky, but you'll be right on
the edge of reliability. You feel lucky?

2. There is NO reason you can't replace your 40 mHz 68EC030 with a 50mHz 68030
in order to add an MMU. We socketed the CPU for this very reason. Just don't crank
up the speed.

There's more from the above fellow in the archive, and (IIRC) there was another engineer or two who essentially said the same thing.

That said, as you mentioned, others have done it and it worked. I've overclocked Amiga hardware before, just never my 530 after reading comments like the ones above (from my standpoint 10MHz just wasn't worth the risk). If you do it, check the temperatures of the PALs with an infrared thermometer at both frequencies (look for anything really heating up), and definitely consider good active cooling... all IMHO.

[Mogsy]

Originally Posted by Damion

You don't have to replace the crystal, the CPU will simply run at 40MHz. My advice would be to not overclock this particular card, the logic wasn't designed/rated for 50Mhz and there's a possibility of damage (as stated by one of designers anyway, you can still find his comments in the usenet archive if you dig a little).

Originally Posted by roy bates

they made one at 50mhz from the factory...

http://www.amiga-hardware.com/showha....cgi?HARDID=68


besides its not overclocked if they made them that way from stock.ive even had one of these at 50mhz it came that way even with an fpu.

Originally Posted by Damion

OK, I dug it up...

and

There's more from the above fellow in the archive, and (IIRC) there was another engineer or two who essentially said the same thing.

That said, as you mentioned, others have done it and it worked. I've overclocked Amiga hardware before, just never my 530 after reading comments like the ones above (from my standpoint 10MHz just wasn't worth the risk). If you do it, check the temperatures of the PALs with an infrared thermometer at both frequencies (look for anything really heating up), and definitely consider good active cooling... all IMHO.

Ahh, many thanks for the heads up. I'm pretty disappointed in that. It would be a shame to damage the thing after owning it from new for over 20 years I guess.

[Mogsy]

Originally Posted by Damion

OK, I dug it up...

and

There's more from the above fellow in the archive, and (IIRC) there was another engineer or two who essentially said the same thing.

That said, as you mentioned, others have done it and it worked. I've overclocked Amiga hardware before, just never my 530 after reading comments like the ones above (from my standpoint 10MHz just wasn't worth the risk). If you do it, check the temperatures of the PALs with an infrared thermometer at both frequencies (look for anything really heating up), and definitely consider good active cooling... all IMHO.

Just for reference, what are the PAL's, please?

[roy bates]

http://www.amiga-hardware.com/downlo...0_mb_f_big.jpg


just behind the simms yuoll see the ic's in sockets,there pal's

[Mogsy]

Thanks. Are all five of the chips PAL's. It was mentioned earlier that the 50MHz version had upgraded versions. Any ideas if these may still be available?

[roy bates]

i dont know if you could get them now.

i wonder if someone has the 50mhz model today,and if the pal's are readable.

[Mogsy]

Hmm, would be helpful if there was one around.

[roy bates]

you could try amibay.





EDIT: sorry, you asked what they where "means",PAL means Programmable Array Logic
just like mach ic's are programmable array logic in banks of pal's.

[pandy71]

You should cool PAL's (widely available small heat sinks should work perfect), you may slightly increase 5V (perhaps up to 5.25V) there is a big chance that everything will work fine.

[Mogsy]

Good idea. How would I increase the voltage?

[roy bates]

Originally Posted by pandy71

You should cool PAL's (widely available small heat sinks should work perfect), you may slightly increase 5V (perhaps up to 5.25V) there is a big chance that everything will work fine.

the parts have a tolerance of +/- 5%(5.25 volts is the upper limit of these parts inluding the memmory)

i dont think its a good idea to overvolt a part that already gets hot in operation.


cooling it down is a good idea,but overvolting at the same time is counter productive and has a negetive effect on other parts on the same rail.