100Mhz Crystal Oscillator Question

[stopthegop]

I noticed on Amigakit they sell a 100Mhz Oscillator as a replacement for Amiga accelerators.  I know in some cases the 68060 can be clocked well over 100Mhz such as with the CT-60 on Ataris, but thats only because it supports faster DIMM memeory.  Is this correct?  Can I clock my 060 up to 100Mhz even with older SIMM memory?  

[redrumloa]

stopthegop wrote:
I noticed on Amigakit they sell a 100Mhz Oscillator as a replacement for Amiga accelerators.  I know in some cases the 68060 can be clocked well over 100Mhz such as with the CT-60 on Ataris, but thats only because it supports faster DIMM memeory.  Is this correct?  Can I clock my 060 up to 100Mhz even with older SIMM memory?  

Short answer:
No, won't happen, you will be lucky to get 66mhz.

[adonay]

i have 80mhz on my apollo 1260 more info about that ask PG.. He seems to be the apollo guru. As i see it is strictly due to board design the apollo can not work on a higher mhz than that either so 100mhz imposible

[matthey]

@redrumloa
From stopthegop's sig it looks like he already has a 68060@66MHz so I guess he was lucky .

@stopthegop
To go much more than 66MHz you will probably need a 71E41J Mask 68060. They are rare and expensive if you find them but supposedly are over-clockable from 90-105MHz. Next you will need SIMMS that can keep up. The rated speed and actual speed of SIMMs vary a lot. 60ns SIMMs will probably get you to 66-75MHz. Turning on the 70ns memory speed in the Cyberstorm PPC/MK3, setting the slower ram speed jumper on the 4060 (4000T), or modifying an Apollo board will slow the ram allowing for faster CPU speed yet. There are also 50ns SIMMs which are usually only found as EDO (may not work on the Cyberstorms). They are also difficult to find but pop up on E-bay from time to time. With 50ns SIMMs and a slower memory setting I would imagine you could get close to 100MHz. There was a web site where an Amiga user mentioned running at 100MHz with the Apollo board and the newer mask 68060. If I'm lucky I'll be doing some testing as I have or will soon have...

68060 Mask 71E41J
4x32MB Crucial (high quality) 50ns EDO SIMMs
2x16MB 60ns rated but 47ns tested non-EDO SIMMs
Cyberstorm MK3 with socket for 2nd oscillator

Sounds like I can have some fun right? Sadly no. My Cyberstorm MK3 is off to the Amiga Center again. With my luck it will be unrepairable this time :-(.

[matthey]

@adonay

Possible on the Apollo 4060...

http://www.webalice.it/gratteri/apollooverclock.html

I wonder if something similar can be done for the 1260?

Also, What is the mask of your 68060 that runs at 80MHz?

[Damion]

stopthegop wrote:
I noticed on Amigakit they sell a 100Mhz Oscillator as a replacement for Amiga accelerators.  I know in some cases the 68060 can be clocked well over 100Mhz such as with the CT-60 on Ataris, but thats only because it supports faster DIMM memeory.  Is this correct?  Can I clock my 060 up to 100Mhz even with older SIMM memory?  

Years ago I had an early (01F43G mask) '060 on a Blizz 1260 card, and its limit was 66 MHz. 70 MHz resulted in random crashes.

Maybe it would have clocked a bit more with a better memory system or a slight voltage increase, but it ran pretty hot as it was... even with a decent fan/heatsink and good ventilation.

The last '060 was basically a mask shrink of the previous version, which is probably why they run comparatively cooler and are able to be clocked further.

[alexh]

matthey wrote:
you will probably need a 71E41J Mask 68060.

Not that it matters much but the 71 isnt part of the mask number. The mask number is E41J ;-)

http://www.freescale.com/files/shared/doc/pcn/945048375992collateral.html?fpsp=1

-D- wrote:
The last '060 was basically a mask shrink of the previous version, which is probably why they run comparatively cooler and are able to be clocked further.

Yup, smaller geometry coupled with more efficient packaging means less heat and more easily dissipated.

On a side note, there is something that no-one has mentioned yet and that is CPU060. A tool that comes with every phase5 based 060 board and allows you to tweak some of the firmware settings. One of those settings is the number of WAIT STATES on the DRAM interface. By changing this setting you could in theory overclock the CPU higher than a 1:1 (or 2:1?) setting will allow. Just a thought.

However by changing WAIT STATES you may reduce performance more than you gain by the higher clock rate.

[adonay]

Hi my card is the Apollo 1260 the 060 is a MC68060RC50 1E41J running at 80mhz 100% stable only problem i had was my a1200 mobo needed timing fixes . And i can tell you there is a HUGE difference in perfomance as for your 100mhz trick sounds interesting :-D wish i had another card too try it out with ..

Again this card was modifyed by PG with extra simm socket and cpu socket as well as the overclock.. i have tried different occ such as 66mhz and 50 but it rocks on 80

[Piru]

@alexh

On a side note, there is something that no-one has mentioned yet and that is CPU060. A tool that comes with every phase5 based 060 board and allows you to tweak some of the firmware settings. One of those settings is the number of WAIT STATES on the DRAM interface. By changing this setting you could in theory overclock the CPU higher than a 1:1 (or 2:1?) setting will allow.

No, that's setmemmode.

[matthey]

@alexh & Piru

The 70ns memory setting increases the wait states to work with 70ns SIMMs and I believe is called that in the ESC boot menu of the 68060 Phase5/DCE boards. Finer control is also available in the menu with many settings I would have to research before changing. I think everything is available in the menu as with setmemmode.

@adonay

I see you have the newer 68060. I would expect the 68060 to be 100% stable at 80MHz. I bet your oscillator frequency is halfed and fed into the motherboard timing as 40MHz since you have problems with the motherboard itself. That would be a problem if you wanted to go faster. The Apollo 4060 only has one oscillator and location for oscillator so maybe doing the mod that adds the wait state also reduces the frequency fed into the motherboard if that guy ran at 100MHz. If your board is similar enough to the Apollo 4060 then this mod may help your motherboard timing problems as well as allowing you to run a higher CPU clock speed. Memory speed might be slower though. The safer bet would be to put a 75MHz oscillator in or increase your air flow across the motherboard (tower?).

The Cyberstorm MK3/PPC can have 2 oscillators (actually 3 with PPC). One can be used for SCSI and motherboard timing and the other for the CPU. This gets rid of the limitations from motherboard timing above. I have never heard of anyone overclocking these boards above 70MHz. Maybe there is some kind of electrical limitation of the board itself.

[adonay]

The safer bet would be to put a 75MHz oscillator in or increase your air flow across the motherboard (tower?).

No the heat is not an issue actually the 060 is not that hot and it is actively cooled . The timing issues is only a problem with the amiga1200 with either 2B or 1D4 i reworked this on my 1D4 but too much hasstle on a 2B "i diddnt want to go shopping for resistors  :lol: . Anyways good luck with your overclock i will be giving my apolloa a new D-box tower a mediator and voodoo 3 soon, after all it is stable after the timingfixes and i cant say i have ever been this close to be satisfyed with a miggy system before :-D

As for limitations it may be limited even in filmware the reson apollo does so good "i think" is that it is made for both 040 and 060 hence the 040 uses 2x multiplier (80mhz for 40mhz cpu etc) and while overclocked the jumper on the card is set to 040 i think too allow such higher frequency ..  

[stopthegop]

@Adonay:

Your posts have made me wonder what magic things PG could do to my Cyberstorm to squeeze yet more horepower from it?  

[adonay]

I dont know why not shoot him a PM or even a email i am sure he could figure out something If he has more of those newer mask 060 chips i wouldent be suprised if it turned out good. Anyways he seem very capable with a soldering iron as far as i can tell i would give it a try.  :-)

[matthey]

@adonay

I'd be happy with a stable 80MHz 68060. One other advantage of the newer mask 68060 is that bugs are fixed which should add to stability and might be a little faster too. I have a Mediator with a Voodoo4 and used a Voodoo3 for a while also. Both cards are very fast in 2D and higher resolutions. If you have been using AGA you will notice a huge difference. The Voodoo3 with a 68060@80MHz will feel like a modern computer. If only we had a more modern better browser we would be set.