Re: Indivision AGA 4000/CD32 Installation
TheCorfiot said:
Could this be the answer :woot:
Mod and tests to be carried out in the next day or two :wink:
Oh sorry, and for you technically minded nosey lot, :laugh:
It's a 1K resistor between +5V and the CCK line which raises the peak to peak amplitude of the clock signal to over 4 Volts, Without it the signal swing is 3.4V
TC 8)
OK ---- Great News :woot:
As you are aware some A1200 Motherboards had an issue where using 28Mhz Graphics modes (ie Super Hires,Productivity..etc) would produce tearing on the screen & flashing Vertical lines.
This is commonly cured by shorting out resistor E127R which alters the CCK (clock)signal sufficiently to eliminate the issue completely.
Now it appears that some A4000's (I have a Commodore Lisa) also suffer from this effect when the Indivision AGA is installed as the CCK line is loaded & the same fault condition occours.
By applying the fix below, adding a 1K resistor between +5V & CCK, then this fault condition is completely eliminated and normal service is resumed
I modified my Indivision AGA this morning, removed all added cooling to ALICE & refitted the lid, the system has now worked perfectly with a clean & stable display for 6 Hours, HighGFX 1024x768 & Superhires Mode is perfect.

int:
A4000 / Indivision AGA owners should only consider this mod IF they have the issues I have described above. It is NOT Mandatory :readit:
Now as a big plea ---- does anyone have a genuine 2MB ChipRAM SIMM they would be willing to kindly donate as I currently have an 8MB SIMM fitted which I agree with you all poses no issues with a real LISA, but I have my suspicions regarding compatibility with IndivisionAGA's FPGA LISA.
Thanks all in advance
TC
