eraser
Well-known member
I am looking for an L2 cache module for my PowerMac 5260. To cut costs Apple released these machines with no L2 cache (which I presume considerably hurt performance) but luckily they left a slot available for upgrade later. The problem is that very few people actually bought the cache module making them difficult to find. The PowerMac 6200/5200 (same motherboard) uses this same cache slot for both its cache and its ROM. After looking at a combination ROM/cache module for a 5200/75 LC I got an idea.
The 5200 and 5260 effectively share a motherboard. The only difference is that a few chips have been updated and generally the 5260 has the ROM on the board and has either a 603e @ 100 MHz or 120 Mhz instead of a 603 @ 75 MHz.
There are 3 modules I am aware of that were made for these Macs:
- L2 Cache + ROM = This module was shipped with many PowerMac 6200 and 5200 units. It contains 256K L2 cache (8 chips) on one side and 4 MB of system ROM (4 chips) on the other side. This module will not work in a PowerMac 5260 apparently because of a ROM conflict.
- ROM only = This module contains only the 4 Apple ROM chips. I notice that comparing the ROM module to the combination module that most of the pins seem to effectively be unused or routed to other pins.
- L2 Cache only = This is the module I am looking for. I assume it contains only the cache chips and no ROM. Apple refers to this as a SIMM (as opposed to a DIMM) meaning that the contacts on each side of the module are redundant.
So my idea: take one of the L2 Cache + ROM modules from a 5200 and desolder the Apple ROM, leaving only the L2 cache side populated. In theory this would let the machine see the cache but there would be no ROM conflict.
Thoughts?
The 5200 and 5260 effectively share a motherboard. The only difference is that a few chips have been updated and generally the 5260 has the ROM on the board and has either a 603e @ 100 MHz or 120 Mhz instead of a 603 @ 75 MHz.
There are 3 modules I am aware of that were made for these Macs:
- L2 Cache + ROM = This module was shipped with many PowerMac 6200 and 5200 units. It contains 256K L2 cache (8 chips) on one side and 4 MB of system ROM (4 chips) on the other side. This module will not work in a PowerMac 5260 apparently because of a ROM conflict.
- ROM only = This module contains only the 4 Apple ROM chips. I notice that comparing the ROM module to the combination module that most of the pins seem to effectively be unused or routed to other pins.
- L2 Cache only = This is the module I am looking for. I assume it contains only the cache chips and no ROM. Apple refers to this as a SIMM (as opposed to a DIMM) meaning that the contacts on each side of the module are redundant.
So my idea: take one of the L2 Cache + ROM modules from a 5200 and desolder the Apple ROM, leaving only the L2 cache side populated. In theory this would let the machine see the cache but there would be no ROM conflict.
Thoughts?