Date: Thu, 4 Sep 2003 11:57:25 -0500 From: Jeff Walther <[EMAIL PROTECTED]> Subject: Re: [SM] Acard 6880 vs 6880M
At 18:44 +1000 09/04/2003, Samuel Tang wrote:
Jeff Walther wrote:
(snipped)
On the VST/Promise cards, the Promise cards require moving several resistors and
some other fiddling.
Promise was the first manufacturer who announced the intention of producing
Mac-compatible IDE cards, but somehow never got around to it. Now that gets me
interested: which model is capable of Mac conversion, and how does one do it?
Hi Sam,
Unfortunately, I've never written the details down.
A friend asked me to convert a few of these cards, so this time I wrote the details down. The following Rnn refer to surface mount resistors. There's some good info on Marc Schrier's Clock Chipping Home Page on how to remove surface mount resistors using the two pencil method.
Move R12 to R16. These are near the top at the left middle.
Move R48 to R46. These are on the right side of the card near the bottom and the top respectively.
Move R10 to R9. These are under the flash chip.
If you have the version of the Promise card that comes with a 66.667 MHz half-size metal can oscillator in the center of the chip, then these additional steps are required:
Remove the 66.667 MHz half-size metal can oscillator.
Move R21 to R19. Also near top at left middle.
Add a 1000 ohm (1K ohm) resistor to R27 next to the osc. position. The R27 is a ways to the right of the pads for the resistor.
All the resistors in question are 1000 ohm, so you don't actually have to move R12 to R16. You could move R48 to R16 and R12 to R46 for example. But the locations I paired are near each other, and doing them one at a time makes it less likely you'll lose the tiny resistors.
One of the resistors is under the Flash chip. So that must be removed. The easiest
way would be to clip the pins and then desolder the (32) pins one by one, but then
you'd need a replacement chip and some way to program it. So I usually do this the
hard way and get all 32 pins to come loose at once so I can reuse the chip. A
replacement chip can run $10 or more, which kills any economy in this conversion.
I use an adjustable heat gun for this. I remove the rear metal bracket from the card, use a large spring loaded clip from Home depot (the metal type with the rubber on the snout) to support the board by clipping it near the opposite edge from the flash chip and then heat the back of the board where the flash chip's pins poke through. Every so often I test the solder around a few of the pins by poking the solder with a dental pick. When it's soft, I push gently on the pins of the chip until they go through/out of the board and the flash chip comes off.
Before beginning I cover all the tiny components near the flash chip in modeling clay so that they don't disappear in the process. It takes 1 to 3 minutes to get the chip off this way (not counting the set up time). This part requires a bit of coordination and forthought. It also helps to be prepared to gently pry the chip from the front if the last few pins get wedged in the holes, but one must be careful not to pry on the chip if the pins are stuck because the solder isn't melted. If the solder isn't melted you'll pull the gromets out of the holes along with the chip's pins and that will ruin the board.
One version of the Promise card has a 66 MHz half can oscillator on the board which
must be removed. Another version does not.
Once all the resistors are in place, getting the firmware in place is still a pain. The
firmware updater from VST will not update the card unless it already has VST
firmware on it.
So, what I do is to install a socket where the Flash chip goes. Then plug in a
programmed Flash chip from a real VST card. Then install the card in a computer
and run the flash updater, but stop at the last step before it updates the firmware.
Then oh so carefully, with the machine turned on, and the Promise card in the PCI
slot, pull the flash chip from the socket and install the flash chip that you desoldered
from the card). Then click on the last button in the firmware updater, and it will
program the VST firmware into the chip which formerly had PC firmware on board.
You can see that in addition to the difficult desoldering, you really need to have an
original (or copy) VST card already in hand, because you need a programmed flash
chip in order to fool the firmware updater into working.
Actually, what I do these days is use my chip programmer to program the flash chip while it's off the card. But this still required me to have a legitimate VST card at one time in order to read the flash chip contents. And chip programmers range from about $200 up to umpteen thousand dollars (mine is about a $500 model), so unless you want one for other reasons, it's kind of pointless to get one just for this.
But for anyone who wants to try this, there's the complete information, in a not very well organized fashion.
Jeff Walther
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