Jepael wrote:The QS5244 is a buffer/driver with very low skew and very strong outputs. It is used to buffer important high speed signals like […]
Show full quote
The QS5244 is a buffer/driver with very low skew and very strong outputs. It is used to buffer important high speed signals like clocks around the board.
Based on GENDAC datasheets and card pictures the memory clock output is buffered and that line has the extra resistor attached, most likely to prevent ringing or signal reflections on the bus to make it work better or more reliably.
Hard to tell, because the component values can be different on different boards, and the boards seem to be of a bit different revision (-005 vs -006), whatever that means. It might mean there are PCB routing changes, or just BOM used so some component values are changed.
Is that resistor banding red-red-gray-black-brown? That would mean 228 ohms which might be a sane termination resistor value.
thanks for the answers,
indeed the cards are a bit different, but apart from the memory chips, some markings, the PCB color tone and the strange resistor they look pretty much the same, so you think this could be some fix made by the factory (as a correction)?
about the color of the rings, I actually have a hard time identifying
it looks to me like brown, green (but pretty dark, maybe black!?), gold, red, red
http://i50.tinypic.com/25ho7f8.jpg
http://i47.tinypic.com/14v1cnm.jpg
now the front of the cards
http://i48.tinypic.com/nmers9.jpg
vetz wrote:Just checked my Monster 3D II 8MB, and it's the B revision. No transistor at the place in the picture.
my rev B card also don't have the resistor in that place
but this rev A card also doesn't
http://www.vgamuseum.info/index.php/palcals-c … d-monster-3d-ii
BigBodZod wrote:I bet this was indeed a factory hotfix before shipping and was corrected on the REV B boards.
However I can't confirm any on my end as I no longer have any Monster 3D boards.
now, I found this
http://www.3dfx.ch/gallery/v/3dfx_collectors/ … CN0107.JPG.html
http://www.3dfx.ch/gallery/v/3dfx_collectors/ … CN0104.JPG.html
the upper card seems to be exactly the same as mine (memory chips and all), it has the resistor soldered into the same place, so it makes sense.
so the card probably was shipped with the resistor already there,
and this would probably mean that it's not related to the problem I have (freezing on quake II) with my rev A 2298 card
I thought this could have been an unsuccessful attempt to fix a problem made by someone, or a mod for better overclocking, so it could be related to the problem... oh well,
is there any software recommended as a good test for V2 stability? I found Q2 probably the easiest to always reproduce the freezing, but in some other games the card looked stable...
