This covers the 486/Py3(-P70(LP)) series of 486 Now! upgrades.
xx- either 25 or 33 y=D (DX) or S (SX) LP is Low Profile
So a 486/33PD3 is a 486DX-33 upgrade, a 486/33PD3-P70 is a 486DX-33 upgrade for the P70 (old style planar)
The upgrade board is the same for DX and SX variants. The
486/33P(D/S)3-P70 is for the old style 8570-061
with the CPU socket below the expansion slots. The 486/33P(D/S)3-P70LP
is for the newer 16 and 20MHz 8573-031/121
and the Japanese 5530.
Carlyle Smith pops up out of lurk
mode and sez
Model 1 2 3 4
8570 16 Long, 20 short Off On On
8570 16 short On On Off
8570 25 Long On On On
5530 25MHz On On On
8573 -031, 061, 121 Off On Off
8580 16 and 20 MHz Off Off On
8580 25 MHz On Off On
All Models Fast Post On On
Fast Post Off Off
If a 8603 mouse error or an XGA display problem occurs, turn 4 Off.