Jeff Walther wrote:
The S in SGRAM stands for Synchronous, which means that SGRAM is triggered off of a clock signal. Memory in older machines, which means everything before the Beige G3, is asynchronous which means that the data comes out or goes in based on some relationship to the address and various Enable signals with no clock.I realize that, but the IIfx has a CPU clock speed of 40 MHz. Modern, commercially available SGRAM can run at speeds in excess of 260 MHz. Tying the clock pin to the CPU clock should take care of everything nicely. The SGRAM will be available every time the CPU can "think".
In other words, one can't use Synchronous RAM chips in the IIfx without going through the kinds of gyrations that would amount to building a new motherboard for the IIfx.
There may be dual ported asynchronous graphics chips around that could be adapted, but any parts of that type are most likely not being manufactured any more.
Jeff Walther
Terry
The clock signal is the last in the mac list of priorities, one of the hurdles when running linux particularly with some models. I've a feeling you are up against it as far as your project goes. I wish you the best of luck but think your fx will be waiting for ram while the ram is waiting for something to do.
At 80ns there is room for improvement with faster memory if that exists.
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