Apple PC Compatibility Card (7" & 12") MS-DOS 6.22 / Windows 3.11 / Windows 95B / Windows 98SE Images
- Thread starter Ron's Computer Videos
- Start date
I already tried 2 different beige G3 boards… so it’s not that…
Nor is it the compatibility cards…
Very intriguing.
Worth taking the working HD from the B&W and popping that in the beige G3? Not sure if it'll boot, but probably?
Apple 7" PC Compatibility Card
I have had problems getting my 7" card to work. It turned out to be a cracked solder joint on the IBM 5x86-100 CPU. It got a hard knock or something since the pins of the QFP-CPU are stressed on the bottom, tilted on the sides and compressed on the upper side.
I reflowed all pins of the CPU and added heatsinks to all chips since they got toasty (especially the ATI Mach 64). I also had some problems with my diy Y-cable that fixed themselves after i screwed the bracket into the PCI-socket.
@croissantking : If you have a spare internal connector cable (GIMO), i would really like to test it in my 8200/120.
-Jonas
I have had problems getting my 7" card to work. It turned out to be a cracked solder joint on the IBM 5x86-100 CPU. It got a hard knock or something since the pins of the QFP-CPU are stressed on the bottom, tilted on the sides and compressed on the upper side.
I reflowed all pins of the CPU and added heatsinks to all chips since they got toasty (especially the ATI Mach 64). I also had some problems with my diy Y-cable that fixed themselves after i screwed the bracket into the PCI-socket.
@croissantking : If you have a spare internal connector cable (GIMO), i would really like to test it in my 8200/120.
-Jonas
Last edited:
Apple 7" PC Compatibility Card
I have successfully changed the bus speed of the 7" Card from 33MHz to 40MHz, resulting in a 120MHz CPU speed (stable as it seems).
On the back of the card, turn the resistor R69 90 degrees to the left (connect it to 5V) onto the bottom pad of the resistor R72.
This changes the input S0 of the SC464 to high which results in the following:
Not every 7"-card may take 120MHz. But i have an IBM 5x86 which are known to be binned better than Cyrix own CPUs. AN IBM 100MHz part is basically comparable to a Cyrix 120MHz part.
Quake went up 19% from 9.8fps to 11.7 fps and the super scape benchmark goes 25% up from 50 fps to 62.5 fps which is more than expected.
There seems to be some more tweaking possible since writing is not cached at all and this reduces memory throughput to about half of what is normal.
-Jonas
I have successfully changed the bus speed of the 7" Card from 33MHz to 40MHz, resulting in a 120MHz CPU speed (stable as it seems).
On the back of the card, turn the resistor R69 90 degrees to the left (connect it to 5V) onto the bottom pad of the resistor R72.
This changes the input S0 of the SC464 to high which results in the following:
Not every 7"-card may take 120MHz. But i have an IBM 5x86 which are known to be binned better than Cyrix own CPUs. AN IBM 100MHz part is basically comparable to a Cyrix 120MHz part.
Quake went up 19% from 9.8fps to 11.7 fps and the super scape benchmark goes 25% up from 50 fps to 62.5 fps which is more than expected.
There seems to be some more tweaking possible since writing is not cached at all and this reduces memory throughput to about half of what is normal.
-Jonas
Last edited:
Apple 7" PC Compatibility Card
I have tinkered a bit with chipset registers and drivers.
The 5x86 can be tweaked a bit with these tools:
Cyrix5x86_Utilities.zip
SIS496 chipset:
datasheet
IDE enhancements: The SIS496 IDE Driver does not work and will prevent Win 3.11 to start.
SIS496 Registers:
Changes to the registers are possible with a tool available here.
L2 Cache problems:
The L2 cache on the card is set to Write-Through but setting it to Write-Back freezes the machine.
The engineers may have intentionally forced Write-Through for the Apple bridge chip to work.
The limits of the cache are limiting further enhancements...
The 128K L2 Cache does only enable cacheing of 16MiB of system memory which further limits the cards usage.
-Jonas
I have tinkered a bit with chipset registers and drivers.
The 5x86 can be tweaked a bit with these tools:
Cyrix5x86_Utilities.zip
SIS496 chipset:
datasheet
IDE enhancements: The SIS496 IDE Driver does not work and will prevent Win 3.11 to start.
SIS496 Registers:
Changes to the registers are possible with a tool available here.
L2 Cache problems:
The L2 cache on the card is set to Write-Through but setting it to Write-Back freezes the machine.
The engineers may have intentionally forced Write-Through for the Apple bridge chip to work.
The limits of the cache are limiting further enhancements...
The 128K L2 Cache does only enable cacheing of 16MiB of system memory which further limits the cards usage.
-Jonas
Last edited: