Butterfly memory

Memory options

The 50 and 75 MHz Butterfly's have 4 and 8 MBs of base memory respectively. The series has a single memory expansion slot that will accept a special 4, 8, 16 or 32 MB small-outline (SO) 3.3-volt 72-pin dual inline memory module (DIMM). Although this is non-parity memory, it ain't cheap.

Here's the options page for IBM memory upgrades. It's interesting to note that IBM no longer advertises 32 MB DIMMs for the Butterfly. (They do exist though; I have three Butterflies with IBM part number 92G7281 DIMMs in them.) In fact, the main ThinkPad 701 page used to say that the maximum memory for the 701C/701CS was 36MB/40MB but now says it is 20MB/24MB.

Third party memory is available from companies including:

* vendors offer 32 MB DIMMs

According to the Kingston web page, the part number for the 32 MB DIMM is KTM TP701/32. The Viking Components web page says the 32 MB DIMM part number is I7281. The other third party vendors do not offer this size. (And now apparently IBM does not either.)

Genuine IBM memory has a three warranty while the third party vendors give "limited lifetime" warranties. It also usually costs more.

Butterfly memory map

Here's my memory map:
Start End Description
000000000009ffff unavailable for use by devices
000a0000000affff chips & tech accel
000b0000000b7fff unavailable for use by devices
000b8000000bffff chips & tech accel
000c0000000c9fff chips & tech accel
000ca000000cbfff pnp bios
000cc000000effff available
000f0000000fffff pnp bios
00100000003effff unavailable for use by devices
003f0000003fffff chips & tech accel
00400000007fffff unavailable for use by devices
0080000000800fff pcmcia card services
0080100000fdffff available
00fe000000ffffff unavailable for use by devices
I used the Windows 95 devices control panel to generate it. It's more detailed than the IBM ThinkPad Memory Maps page. This information was invaluable while configuring Wildboar.
Related Craig's Butterfly pages:
satan inside

Back to Craig's IBM Butterfly page

Copyright © 1996, 1997, 1998, 2001, 2005
Craig Leres