Oscilators question

[delshay]

@Vulture

where are you going to put the 75Mhz osc 68k or PPC side or both?

[delshay]

Vulture wrote:
Hi ppl!

I'm looking for a 75Mhz 8-dil oscilator for my BPPC/060.
Except of the fact that I can't find anything on an amigashop, I really need some advice if I'm looking for a 3.3v or 5v part. Also, I've mostly found multi-frequency oscilators, anybody knows of a good source with fixed frequency oscilators, just the one I'm after, 75mhz. Preferably a source which will ship only one or two crystals to a customer.

Thank you in advance!



PS

Anyone already having a 75mhz 8-dil crystal and feels like parting ways with it, he's welcome to PM me, thx!

WARNING WARNING WARNING WARNING WARNING WARNING WARNING

if you fit a 75Mhz osc without cooling the four microchips
( very important ) and SCSI you will damage your Blizzard PPC card.

[delshay]

the Blizzard PPC card has been tested and 68k side has been overclocked as high as 83.66Mhz but you may be limited to the amount of ram that can be installed.

if you get a green screen on bootup your memory chips are to slow.

system info 3.18 shows MIPS 65.35 ( 64Mb ram) at full speed ie in the Blizzard PPC ram menu setting set-to no precharge.

CAUTION the cypress microchip near the Bvision socket can runs as high as 58c without overclocking. iv detected this chip for some reason run a littel hotter than the other cypress microchips.

[delshay]

another update ( second test )BETA

iv just tested the Blizzard PPC card it seems the max bus speed is 75Mhz uncomfirmed ( to be updated )

on os3.9 i got lockups this may be a WARPUP or timing problem.

i loaded OS4 only with dual 75Mhz osc and did not find a problems,will load 3D games on next test.

NOTE ON MEMORY SIMM SPEED

is very important as i had many problems getting the Blizzard PPC to work at 75Mhz bus speed and many simm module will fail.

the marking on one of my 64Mb simm is marked 60ns but this is the only simm that booted the Blizzard PPC above 75Mhz speed ie 83.66MHz ( 68k side only) but was unable to activate Bvision card,i was able to play quake without any problems on AGA screen at this speed.

MEMORY 128Mb MODULE

all 128Mb modules failed to work with dual 75Mhz osc even simm marked as 50ns.

SOLVED 128Mb MODULE

i modify the simm itself 128Mb module it now boots without a problem with OS4 but a full test will have to be done to comfirm card is ok at this speed.

the above test is BETA.

*** ALL OVERCLOCKING AT YOUR OWN RISK ***    

[delshay]

da9000 wrote:

delshay wrote:
i modify the simm itself 128Mb module it now boots without a problem with OS4

Can you be more specific? What did you modify on the SIMM itself?

Thanks

i will post what i did when more test is done but can comfirm that the  Blizzard PPC booted with dual 75Mhz osc and for the very first time with a single 128Mb 50ns simm module with dual 75Mhz osc.

i will upload picture of grimreaper of Blizzard PPC if i get enough request at this new speed.

NOTE: the grimreaper is a deliberate fault put on OS4 to see whats happening.

also note this Blizzard PPC is *not* standard,it's a TEST CARD ONLY and more work needs to be done and be solved,this is not a easy task as i have no schematics.

[delshay]

darksun9210 wrote:
i like the "all overclocking is at your own risk!"

yeah, not to mention the risk of loosing a 15year old piece of electronics that seems to be getting rarer as time goes on. who can fix one of these if you cook it? :-o

i'd hate for mine to go bang so cooling cooling cooling! :lol:

that why it says TEST CARD ONLY.

[delshay]

Vulture wrote:
Cool! Keep us updated! Very interesting project!

will do but if i can't get the PPC to work at 83Mhz bus speed,one of my projects has already failed.

if i can get the PPC side to work at 83Mhz bus speed i will do my best and try and fix Bvision.

[delshay]

third update

*comfirmed* Blizzard PPC can have 75Mhz bus speed but there maybe some limit to the amount of ram that can be installed.

i was able to run heretic & hexen and did not find any problems with OS4 but there are somethings that need to be fixed.

there may be a timing problem & will need to be fine tuning in-order to run this frequency.

it will work fine on OS4 or 3.5/3.9 but when using WARPUP under 3.5/3.9 i got some lockups.

if WARPUP is not used under 3.5/3.9 this is fine.


SIMM MODULE 64Mb

i try another 64Mb module ( simm 1 )@ 83Mhz this module failed to work but has the same part number as my other 64Mb module ( simm 2 )which works fine @ 83Mhz.

simm 1 has a different layout to simm 2 so this make me belive one of the following.

1. simm 1 chips is not what it says on the chip

2 simm 1 may have timing problems because the card is bigger ( longer tracks ).

NOTE: simm 2 is very small and can not be smaller,its very compact.


CONFIG

in-order for the Blizzard PPC to work @ this new speed you must have the following.

1. your Blizzard PPC card will need at least 2 modification

2. 50ns simms

3. 5v voltage line must read 5v on the Blizzard PPC/Bvision card.

NOTE: feeding extra power at the floppy connect will *not* be enough for it to work.

a reading must be taken with a meter and must read 5v on the Blizzard PPC/Bvision (mandatory).

if it reads 4.8 it will not work. it may possibly work with 4.9v.

[delshay]

FINAL UPDATE:

Blizzard PPC has now been clocked with 80Mhz bus speed with Bvision & 64Mb simm working with OS4,and for the first time with 128Mb simm module ( BETA ).

NOTE: there was the odd random error with 128Mb simm,so more test will be done.
 
it also booted @83.66Mhz bus speed on AGA screen only with 64Mb simm only with OS4 for the first time so more test is also needed here.

[delshay]

@75Mhz bus speed and above i was unable to use both simm slots,ONLY ONE simm slot will work at a time.

as stated before the Blizzard PPC seems to like certain type of ram chips when i overclock over 75Mhz.

the second 64Mb simm now works,the bigger of the two simm card with the same type of chip,but compact simm card may have a advantage shorter tracks.

-----------------------------------------------------------

SIMM MODULE:

the one simm that thats not giving any problem is so compact you can't see the capactiors.

i also posted above,the layout of the simm may also be important if useing A1200 desktop.

there are MANDATORY setting which i already posted.

-----------------------------------------------------------
as stated before simms marked with 50ns,some will have problems @75Mhz and above.

performance is also unknown with the above bus speed,lots of testing is required.


BLIZZARD PPC RAM SETTINGS:

NOTE: *all* test in this project was done with Blizzard PPC ram setting set to NO-PRECHARGE.

no test was done with 70,60ns or read/write settings in the Blizzard PPC ram settings.

** all test done with max ram speed setting **