Oscilators question

[Vulture]

Cool! Keep us updated! Very interesting project!

[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.

[Vulture]

Awesome!  :-)

[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.

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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.

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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 **