The new Apple Coax/Twinax card offers no new functionality, but it does
resolve a somewhat rare incompatibility problem with the Macintosh Display
Card 8*24 and Macintosh Display Card 8*24 GC. The only difference between
this "new" card and the "old" one is that the inductor/ferrite bead
replaces a jumper wire, and the masking on the board says that the board is
revision "B."
You should consider upgrading to the new cards if you have the following
problem:
MacDFT hangs on boot when the initial "splash screen" appears. MacDFT
hangs before the Window Manager completes drawing the window frame, or
shortly after the frame draw and the content region goes black. This
problem happens often on systems with 8*24 style video and Coax/Twinax
cards. It is also more likely to happen on a Macintosh IIci, Macintosh
IIcx, or Macintosh IIfx than on a Macintosh II or Macintosh IIx.
But a similar problem has a different solution: Some NuBus conflicts happen
with the Portrait or Workstation display cards and the Apple Coax/Twinax
card. The error shows up when launching MacDFT. At launch, the Macintosh
bombs and gives a bus error (if the system has MacsBug installed) or
displays a system error of ID=28. Use A/ROSE v1.1.2 to fix this problem.