Dip Switches - Zenith Z-100 Reference Manual

The RAM ICs feature on-chip refresh which is initiated when a given address
is read. The card also provides the necessary circuitry to control wholesale refresh
at required intervals, to arbitrate read, write, or refresh requests, and to properly
time the various memory access operations.
The memory cards are designed to be
and related software and firmware.

DIP Switches

DIP switches located on the CPU card are conflgured to reflect the amount of
memory residing in your system. Refer to Chapter 4 for the correct settings of
these switches for your system.
Configuration Jumpers
J401 is a configuration jumper located on the memory card used as a card select
jumper. If only one memory card is installed, J401 should be positioned to the
left (away from the edge connector) marked '1st'. lf the system has two memory
cards, position the jumper on the card to be designated as the first block of
320K memory, to '1st', and the jumper on the card containing the second block
to the right marked '2nd'. lf 256 kilobit RAM chips are installed, only one card
is required, and J401 should be positioned to '1st'.
Refer to Figure 6.1 for the location of jumper J401.
J402 and J403 allow you to select the port address of the parallel interface. Refer
to the Parallel Port Selection section in Chapter 8 for information pertaining to
these jumpers.
System Memory
c omp l e t e l y
compatible with the IBM PC
Page 6.3