PowerBook 1400-series


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The PowerBook 1400-series has two 80-pin motherboard memory expansion slots addressed along a 32-bit data path. These computers require unique, self-refreshing, Fast Page Mode (FPM), low-power grade, 70ns, PB1400 Memory Expansion Cards in either 8MB, 16MB, 24MB or 32MB capacities.

One memory expansion slot is intended for use only by Apple Computer, with the other intended for use by the end user. Accordingly, the 1400-series ships in two configurations:

• 12MB (8MB RAM soldered to the logic board and a 4MB module in the Apple Factory RAM slot); or

• 16MB (8MB soldered to the logic board and an 8MB module installed in the Apple Factory RAM slot).

Apple technical documents stress that PB1400 modules must utilize TSOP (thin small outline package) memory. Due to their slim form factor and unique signal line addressing, these cards cannot be used in other PowerBooks, and modules intended for use in the Factory slot do not appear to be compatible with the Customer slot, and vice versa.

Depending on the amount of RAM installed in the Apple Factory RAM slot, the addition of a single 4MB, 8MB, 16MB, 24MB or 32MB expansion module yields memory configurations of 12MB, 16MB, 24MB and 40MB.

Fortunately, by "stacking" memory cards attached to the Customer RAM slot, utilizing 80-pin RAM expansion modules designed to be "piggybacked," memory configurations up to 64MBs are attainable. Two 24MB modules stacked, with 16MBs of factory-installed RAM on the logic board and the Apple Factory slot, yield the maximum configuration of 64MBs. Size restrictions and limitations in memory addressing prevent the stacking of modules larger than 24MBs.

Apple documentation also stresses that third-party modules may not be universally stackable, meaning that modules from one vendor may not be compatible with Apple's modules, or modules from yet another vendor. Module size and shape, in this case, is of paramount importance. Caveat emptor.

The PB1400-series ships with a Motorola 603e microprocessor running at either 117MHz (116.67MHz) or 133MHz, while the processor bus operates at 33.33MHz and the I/0 bus at 25.175MHz. These two buses are bridged by the PBX IC memory controller, which also provides ROM and RAM memory control. Significantly, the 133MHz variant also includes a 128K L2 cache, the first ever in an Apple PowerBook.

Specifications
Logic Board RAM		8MB.
Supported Modules		8MB, 16MB, 24MB, 32MB.
Number Expansion Slots		Two (2) (1 customer, 1 factory).
Soldered VRAM		512k / 1MB.
Number VRAM Slots		One.
L2 Cache Supported		128k L2 in PB1400c/133MHz only.
Module Type		70ns PB1400-series RAM Expansion Card.

While some of the products mentioned on this page may no longer be available, the information about these products remains available to those who may need it.

Be sure to mention the model number in the Comments field of the Ordering Form
when ordering upgrade modules from MacGurus.