Going to overclock Apollo 4060

[IvanEBC]

Hi Folks.

I have a friend who will be soldering a socket in place of the Apollo Crystal so i can easily dabble with higher clock speeds to overclock without having to resolder with every attempt.

So while i do not go in completely blind, i have read and read as much as i can on overclocking these and just wish to VERIFY info and see if i can grab some answer on stuff i have not seen.

The CPU on the Apollo card is
XC68060RC50A
Top Corner says
01G65V
QEFJ9826A
Malaysia

Is this enough info to be able to tell me .. what's the highest overclock i should expect as i understand different revisions have different achievable maximums?
I have already put a heatsink and fan on it to keep it cool

So i understand the crystal (silver boxxy ting) needs to be changed... what is the part i'm actually needing to buy from the Electronics store?

I read over and over that ram speed needs to be considered... the board does have 128mb fully populated and i got 16mb in the base 4000 as well, what would i be looking for to know if these are capable to running?

Lastly .... is there a way to measure how hot things are running? What parts am i looking to temp test? Do i use one fo those laser heat guns to measure, and what temps are within the safety limits?

This is a page i've had some info from but wonder if there's a better source and explanation or if this is even relevant?
http://www.webalice.it/gratteri/apollooverclock.html

Sorry, its alot at once isn't it ....

[Chucky]

that cpu will get HOT.. especially going above 66MHz. and going above that you usually also need to move a small SMD resistor to halve the memoryspeed.

with a Rev6 CPU you can do 100MHz. but with that old revision. everything above 66 is not reallyrecomended.(and you WILL need cooling)

[pandy71]

Small increase in voltage (not more than +10% to stay within safe limit) may improve chances for stable overclocking, probably best way will be use of some programmable frequency generator and using frequency with relation to Amiga system CDAC clock (CPU working more or less synchronously with remain system).
Nowadays cooling should be not a big problem as modern PC components dissipating few hundreds of Watt.

[IvanEBC]

So with the revision i have, simply going to 66Mhz is an easy straight up deal with no other modifications ...... i'll likely stick to that upgrade for now.... and you are saying what i got will suit that?

What's the part i need to get?

Tried searching for "apollo 4060 overclock parts" and i get results for sewing machines haha

[Chucky]

I think 01G65V is rev 1.. so just change oscillator.. (and add heatsink/fan)

[IvanEBC]

Anyone able to point me to the correct Oscillator?

The confusion is this... i believe the current one shows 25mhz which you double to get the "real" mhz, meaning the 060 runs at 50Mhz.

So i assumed i was after a 33Mhz Osc. but everyone says a 66Mhz, now i assume (again i assume) they are just saying the final CPU speed of 66Mhz, but the OPsc should actually be 33Mhz printed on it, but i do not think this is the case. Amigakit seems to be out of the ones i want, anyone know a source and a link to the correct one i would actually need, some have this text saying 14dil or 8 dil?

[Chucky]

the 060 50MHz have a 50MHz oscillator. 040 however a 25MHz have a 50MHz oscillator

and I think the cyberstorm takes both 14 and 8 DIL ones. avaible in tons on ebay.. make sure you have the 5V ones.

[Marmes]

Do it
Get a Rev6 first

[Chucky]

Rev 6 is absolutley the best way to go..

and if you need, I have a stock of 6pcs and on monday I will get 10 more..
(yes.. it IS kinda crazy )

[IvanEBC]

Is this the correct part to go from 50mhz to 66mhz
http://au.rs-online.com/web/p/crysta...F_430822%7Calt

I'm not buying more CPU's at this time.

[Chucky]

Should work..

[IvanEBC]

*Waits for delivery*

In the meantime, what do you guys use to show correct speeds of an 060 board? I tried AIBB but it shows 44mhz as the current speed,
I tried OLD sysinfo and it shows as an 040, tried the new sysinfo and it shows as a 060 but apparently it is flawed with 060 detection according to the readme.

[Chucky]

Whichamiga is the only software that can report MHz any good..
(AND type of cpu)

[IvanEBC]

the 66Mhz chip is in but the Amiga 4000 powers up but no posting of any type, screen doesn't even appear to power up, any suggestions?

Quick pic of the old chip and the new one together....

[IvanEBC]

Wow - looks rubbish, likely no help, but need to run out the door, will check back later this evening.

[Chucky]

MAYBE you need to halve the memspeed already at 66MHz..

IF you do this modification your memory would slow down, this is a MAJOR drawback, but on the other hand you can run your CPU faster, some people reported that they used 68060RC60A in over 80Mhz.

Also not that this modification is NOT tested by me (yet), and if you try, PLEASE mail me and tell me if it worked (it should.).

1. Remove the card from the machine.

2. Move the jumper beside the oscillator from '060' to '040'

2. Look under the turboboard, about down under the jumper, there it should be a soldered jumper marked 'pad', and connected to 'gnd', modify it so it's connected to the right solderpad instead.

3. Reassemble the machine and test your card.

[IvanEBC]

Yeah, this goes with that link in my OP, but i wanted to keep it happily at 66Mhz as i believe i didn't have to mod it, but i guess my revision CPU might be the factor or my memory is not fast enough...

I did try the jumper in the 040 position but no go there.
If the ram speed is the issue, couldn't i maybe REMOVE all the memory from the CPU board? Though does this affect the memory on the A4000 mainboard?

Once again i think something will be easy and i've jumped in too deep.

[Chucky]

Just moving the 060 jumper to 040 isn't enough. you MUST also move that SMD resistor or it will give you a black screen.

[IvanEBC]

Thanks for your help Chucky. The system is now at 66Mhz.
I'm waiting for the 80Mhz crystal and your rev6 CPU to see if i can push it a little further, there's already a nice heatsink and fan on top helping it to stay cool.