> The PowerBook 2400c computer accommodates one SO (small outline) DIMM for > RAM expansion. The DIMM can have either 16 or 32 MB of additional RAM. >
Obviously, this is false.. 64M and 96M modules exist. > The mechanical characteristics of the RAM expansion DIMM are given in the > JEDEC speci�cation for the 144-pin 8-byte DRAM SO DIMM. The PowerBook 2400c > computer can accommodate an SO DIMM with a height of 1.0, 1.25, or 1.5 > inches. While the JEDEC speci�cation for the SO DIMM de�nes a Serial > Presence Detect (SPD) feature that contains the attributes of the module, > the Macintosh PowerBook 2400c computer does not support the SPD feature. > The computer requires the DIMM to contain EDO DRAM devices with access > times of 60 ns or less. The card itself must be an SO-DIMM I take it... > IMPORTANT - Unlike the RAM expansion module for the PowerBook 3400 > computer, the SO DIMM for the PowerBook 2400c computer does not require an > address buffer. > That's a plus... it can take unbuffered EDO RAM... cheaper, easier to find... > The PowerBook 2400c computer can accept a DIMM that uses 64-megabit DRAM > devices. The electrical characteristics of such a DIMM must be the same as > those of the corresponding expansion module for the PowerBook 3400 > computer: the DRAM devices must be 4 M by 16-bit devices with 12-by-10 > address multiplexing, and the connections to device address bits 9 and 10 > must be swapped on the DIMM. It sounds like a modified 4x64 part. 32MB chips... 16-bit bus... 4 devices... 64-bit total.. sounds like a standard part so far.. You're right though, Dan. That part about the address bits being swapped.. I wonder if that's standard practise or not? > Type of DRAM device > 512K by 8; 10 row bits, 9 column bits > 2M by 8; 12 row bits, 9 column bits > 1M by 4 or 1M by 16; 10 row bits, 10 column bits > 2M by 8; 11 row bits, 10 column bits > 4M by 1 or 4M by 4; 11 row bits, 11 column bits > 4 M by 16; 12 row bits, 10 column bits > These sound like per-chip specifics... useful for manufacturers... but is it useful for us? > RAM Banks > The RAM expansion card can have up to four banks of RAM. Banks can be 4 MB, > 8 MB, 16 MB, or 32 MB in size. > 4x32MB= 128MB RAM cards.. in addition to what's on board? 128 looks like the spec max. on the card itself... The rest is more chip-level specifics. Pico-farads and millivolts and whatnot. Perhaps ... 3400 chips on a bare SO-DIMM? $0.02 -Andrew ---------- Duo/2400 List, The friendliest place on the Net! A listserv for users and fans of Mac subportables. FAQ at <http://www.themacintoshguy.com/lists/DuoListFAQ.shtml> Be sure to visit Mac2400! <http://www.sineware.com/mac2400> To unsubscribe, E-mail to: <[EMAIL PROTECTED]> To switch to the DIGEST mode, E-mail to <[EMAIL PROTECTED]> Need help from a real person? Try. <[EMAIL PROTECTED]> ---------- Dr. Bott | 10/100 Ethernet for your 2400 is finally here! MPC-100 | <http://www.drbott.com/prod/mpc100.html> RoadTools $30 PodiumPad available at Apple retail stores, $20 Traveler CoolPad at Staples. Both in white for iBooks at <http://roadtools.com> Midwest Mac Parts ][ <http://www.midwestmac.com> After-market parts for Macs. ][ 888-356-1104 ][ MacResQ Specials: LaCie SCSI CDR From $99! PowerBook 3400/200 Only $879! Norton AntiVirus 6 Only $19! We Stock PARTS! <http://www.macresq.com>
