ZiLOG Z80 Handbook page 253

NMI signal, nonmaskable interrupt, may be connected to the S-100
bus by connecting the NMI signal to the VIO signal of the S-100
bus, the highest-priority vectored-interrupt line on the bus. The
ZPUTM board requires +5 VDC only.
TDL Z16TM BOARD
The Z16 board (Fig. 18-2) is a low-power, static memory board
with a cycle speed of 200 nanoseconds. The board may be obtained
in kit, or assembled form, with memory increments from 4K to 16K
bytes. The fully populated version is 16K bytes (thirty two 4K by
1-bit chips). Power-supply voltages required for the Z16 are -±5
VDC, and 12 VDC, and are available on the S-100 bus.
Courtesy Technical Design Labs, Inc.
Fig. 18 -2. TDL Z - 16TM board.
The Z16 board has several unique features. One of these is a
memory-protect capability which will prevent selected 1 to 4K
segments of the 16K board from being accessed for a write. The
memory protect is switch selectable. A battery backup capability is
provided on the board, with the addition of an external battery pack
with voltage sensing. Logic for memory-bank switching is also pro-
vided on the board. By means of an external Memory-Management
Board, banks of 16K memory may be connected, or disconnected,
from the system bus. This means that two (or more) complete 64K
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