32-Bit Memory Expansion Bus - DTK Apex 386/33 User Manual

Output Port Bit
Pin 21 - Bit 0
Pin 22 - Bit 1
Pin 23 - Bit 2
Pin 24 - Bit 3
Pin 35 - Bit 4
Pin 36 - Bit 5
Pin 37 - Bit 6
Pin 38 - Bit 7

32-Bit Memory Expansion Bus

The 32-bit memory expansion bus optimizes the memory subsystem
to take advantage of the 32-bit architecture of the 80386. This bus is
not intended to be a general-purpose, industry-standard of the 32-bit
expansion bus. It is simply a mechanism to optimize the performance
of the PEM-3301 memory subsystem for the 80386 architecture.
Definition
System Reset
Gate A20 of system processor
0 A20 inhibited
1 A20 Not inhibited
Undefined
System speed selection
0 Normal
1 33MHz, Turbo
Output buffer full
0 Not full
1 Full (IRQ1)
Undefined
Keyboard clock (output)
Keyboard data (output)
Chapter 6: Appendix 43