The report last time, regarding installing RAM upgrades in G3 Series PowerBooks (and an error in GURU's description of these models), generated much reader email. Here are the highlights:
A reply from NewerRAM re GURU error and installing in the bottom slot Terry Unrein (of NewerRAM) writes:
"You have properly identified an error in GURU 2.7. The new PowerBook G3 does indeed have 2 slots. We will correct this in the next release of GURU.
The supposition that only Apple can add memory to the bottom RAM slot is a stretch. Although Apple's warranty prohibits anyone except authorized Apple service personnel from upgrading the memory, the installation is simple and is covered in the installation instructions which are optional when buying from NewerRAM."
More comments on installing RAM in the bottom slot Jack Christensen was able to successfully install a 64 MB module in the lower slot (and a 128 MB module in the upper slot), although he did note some potential problems. For example: "The seating of the CPU board into the sockets on the backplane was such that it was possible to believe I had correctly made the connection, when in fact, I had not...After my experience, I felt that Apple's recommendation that bottom slot installation be performed by a trained technician really holds true."
David Muszynski writes: "I read in an article in Macworld that it is more difficult to access the RAM slot on the bottom of the processor card in a G3 PowerBook, but it is by no means an operation that only Apple can accomplish."
Re: Installing Hyundai RAM Regarding the claim that "you cannot add another memory module with Hyundai chips on it," Jack Christensen notes a technical error in the item: "The statement that Hyundai RAM modules for the PB G3 series are 'drawing too much voltage' is incorrect. Electronic circuits do not 'draw voltage,' they 'draw current.' And I can guarantee you that the PB G3 power supply can provide the required current if a memory module is operating correctly. My assumption pertaining to the difficulties some people are having with installation of RAM in the G3 series, particularly in the lower slot, is that RAM modules from some manufacturers are not meeting the timing specifications correctly."
Chris Ferebee was unable to get either of two 128MB modules to work. The machine either would not boot or would report numerous errors after booting. He never identified a sure cause but notes that "the DIMMs were made with Hyundai chips, so the theory you mention may be correct."
[Note: I expect to hear word from Hyundai on this matter later today.]
More reports of errors in GURU We received a few more reports of errors in GURU 2.7. For example, Brian Opitz writes: "GURU incorrectly lists the number of RAM sockets, type, and maximum capacity of installable RAM for the iMac. Both the Apple specs and the downloadable PDF file for the iMac list the correct specifications."
Several readers noted that GURU incorrectly lists the RAM for G3 Macs as 60ns DIMMs. It actually has 100 MHz/10 nanosecond SDRAM (see TIL file).