System Support Functions
The Mark V motherboard has the following standard AT-compatible system elements:
●
seven Direct Memory Access (DMA) channels,
• Channels 0 - 3 for 8-bit data transfer, and
• channels 5 - 7 for 16-bit data transfers.
●
sixteen interrupt levels,
Supports eleven levels of interrupt:
IRQ3 - IRQ7, IRQ9 - IRQ12, IRQ14, and IRQ15.
●
three programmable timers,
●
a system clock,
●
standard I/O capability, including:
• uses 32-, 16-, and 8-bit memory devices, and
• uses 16- and 8-bit I/O devices.
●
I/O bus operating at 8 MHz for the 33 MHz Mark V and 10 MHz for the 40 MHz Mark V.
●
8- and 16-bit IBM AT-compatible expansion slots,
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the standard I/O address space of 100h through 3FFh,
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24-bit memory addresses to access 16 MB of memory,
●
uses the I/O channel check to generate an NMI,
●
has I/O wait state generation,
●
has an open bus structure (allowing multiple microprocessors to share the system's resources, including memory),
●
allows system memory refresh from channel microprocessors,
●
has a real time clock that is crystal controlled and has a battery back-up,
●
provides a standard 5-pin IBM AT-compatible DIN connector for the keyboard,
● supports a hardware Deturbo switch,
●
has a keyboard lock to prevent unauthorized access, and
●
has a standard speaker attachment.
Summary of Contents for 42 Series
Page 1: ...American Megatrends Inc Series 42 Mark V Baby Screamer 80386 Motherboard User s Guide ...
Page 2: ...MAN 642 Rev C 9 11 92 ...
Page 13: ......
Page 35: ...A29 SA02 B29 5 A30 SA01 B30 OSC A31 SA00 B31 GND ...
Page 59: ......
Page 82: ......
Page 85: ...SRAM Locations ...
