Although I group the IIsi with the non-Nubus Macs, it shares features with the SE/30 and the Nubus Macs. The IIsi has an SE/30 PDS for expansion. With an adapter, this can be converted to a Nubus slot. But since it is neither a compact Mac nor comes standard with the Nubus adapter, I've arbitrarily lumped it with the LC family.
The IIsi was designed as a less expensive, less expandable alternative to the IIci. Cost saving measures included eliminating Nubus expansion slots, soldering 1MB of RAM to the motherboard, and using a slower CPU. Although the IIsi was marketed as a 20MHz computer, users quickly discovered it used parts rated at 25MHz or faster. Chipping the IIsi to 25 or even 28MHz was not unusual.
Like the IIci, the IIsi uses onboard RAM for video, which slows the computer. One way to speed things up is to add either a PDS or Nubus video card. Another is to set aside the first 1MB of RAM, since that is the bank shared for video and program space. This can be done by creating a large-but-slow 768KB disk cache or using IIsi-RAM-Muncher by Paul Ripke <firstname.lastname@example.org>.
This page and site ©1997 by Daniel Knight.