CompuServe Messages

There are also a number of processor cards that don't AutoConfig memory if you don't want them to. As an example, I have a PPI 040 board with 8MB and a GVP SCSI card with 4MB. Currently the PPI autoconfigs 2MB in Fast RAM space and the GVP autoconfigs 4MB there for 6MB total. When the machine boots, a PPI utility program adds the other 6MB of RAM on the 040 board into the memory pool at an address above the 8MB Fast RAM barrier (above the ROM in fact — into the realm of 32-bit address space). I *could* have the PPI board autoconfigure *NO* memory and then put 8MB on the GVP card. That would give me 8MB of Fast RAM and 8MB of 040 (32-bit) RAM. That, according to the PPI manual would cause things to slow down though since the 040 would have to go through the bus to access any configured RAM until the 32-bit 040 RAM is added to the RAM list. By that time, all the device drivers and filesystem code will be using the 16-bit GVP RAM space since it will be the only Fast RAM available. This, once again, will cause a slowdown since the 040 will have to access 16-bit RAM to do any filesystem stuff from that point on. Yuck. So, it's a good idea to make sure that some of your 32-bit RAM can be autoconfigured for the purpose of putting boot-time code into it. 32-bit RAM is almost always configured with a higher allocation priority than 16-bit RAM so that it gets used first.