DIGITAL-LOGIC MICROSPACE MSM286 Series Technical User's Manual page 19

DIGITAL-LOGIC AG
4.7 CPU and Bus Variable-Speed Options
A powerful microprocessor represents the central element in the MICROSPACE. The MICROSPACE
MSM286 is designed to operate at a variety of clock speeds, determined by the value of the master
clock oscillator. Standard product is currently available from Digital-Logic AG with 14 MHz for F8680
CPU and 25 MHz for 3/486 CPU clock rate only. Appropriate speed CPU, RAM, and ROM devices
must be used, depending on the CPU clock rate. Reducing the CPU speed can be useful in lowering
system power consumption for battery powered applications, or in increasing the system operating
temperature range by reducing the amount of heat generated by key system components such as the
DRAM memory. Operation of the AT Expansion Bus at half speed may be required to allow the use of
plug-in cards which were designed to be used in older PC compatible systems with lower system
clock rate, or to permit the use of longer bus expansion cables. Use the F8680.EXE Tools for modi-
fying the Bus or CPU clock.
4.8 ROM-BIOS Sockets
A EPROM socket with 8-bit wide data access normally contain the board's AT compatible ROM-BIOS.
The socket is intended for use with a 27C512 to 27C080 EPROM (or equivalent) device. The board's
wait state control logic automatically inserts four memory wait states in all CPU accesses to these
sockets. The ROM-BIOS sockets occupy the memory area from F0000h through FFFFFh; however,
the board's ASIC logic reserves the entire area from C0000h through FFFFFh for on-board devices,
so this area is already usable for ROM-DOS and BIOS expansion modules.
Consult the appropriate address map for the MICROSPACE ROM-BIOS Sockets.
4.9 Onboard DRAM Memory
DRAM: Speed:
Standard: 2 MByte DRAM soldered
None Standard: 1 MByte DRAM soldered
0.5 MByte DRAM soldered
( ask Digital-Logic AG for minimum quantities and prices)
4.10 Keyboard
Type: XT-Keyboard needed
Connector: J5 Utility Connector
Pinout: Pin 5 = Keyboardclock
Pin 6 = Keyboarddata
Pin 7 = Ground
Pin 8 = +5V
70ns
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MSM286 Manual V6.4