Signal RCST# On Beige G3 ROM Module?

[trag]

Anyone know what this signal does? It's connected to pin 35. It's shown on this schematic (page 6)

https://www.macdat.net/files/pdf/apple/schematics/apple/powermac_g3_gossamer.pdf

On actual ROM DIMMs, on most of them it's not connected to anything. On the 820-0961A module it goes to a resistor position, the other pad of which goes to pin 12 of the Flash/ROM chips, which is Chip Enable. But resistor is not installed, suggesting that CE on these modules is just left floating, which is bad practice. Definitely not Grounded the way it (CE_) should be.

I'm looking for a pin that perhaps should be used for RY/BY#

 

[trag]

Never mind. CE# of the chips is tied to pin 115 on the DIMM. Grackle (MPC106) has two RCS signals, RCS0 and RCS1 and the former goes to pin 115 and the latter to pin 35, but pin 35 is not connected to anything on the DIMM except that blank resistor.

Also, signal name is probably RCS1#, not RCST. But on the schematic there's a line on top, instead of a #, so it makes the 1 look like a T.

 

[DBJ314]

Does this mean Gossamer has all the connections to allow a 16MB ROM DIMM? Or a DIMM that is 8MB ROM and 8MB SRAM in a really weird spot? It looks like it might work.

 

[stynx]

Does this mean Gossamer has all the connections to allow a 16MB ROM DIMM? Or a DIMM that is 8MB ROM and 8MB SRAM in a really weird spot? It looks like it might work.

No. The RCS1 is used to read status bits instead.



There is a BurstCAP signal (Burst Capacitor?) that is connected to the ROM socket and i suspect that the signal is used to read if the Flashrom is ready after programming without selecting the ROMs itself. Its most likely a bit of trickery to get the right time when all Flash-chips are ready to be accessed after programming.