Technical information

CHAPTER 1
Introduction
Appearance and Features 3
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Direct memory access. A DMA channel supports I/O transfers when memory is
installed on the card; when using shared memory, DMA is provided through the
Macintosh system.
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Video support. A VGA video system on the card supports Macintosh monitors from
13-inch through 20-inch size and all available VGA monitors.
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Sound card. The DOS Compatibility Card provides standard PC sound output and
comes with a sound expansion card that produces 16-bit sound output compatible
with Sound Blaster cards. Sounds are played through the host computer’s sound
output jack and built-in speaker.
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Serial ports. The DOS Compatibility Card uses the host computer’s two serial ports
by way of serial port interfaces emulated in hardware.
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Parallel port. The card has access to a printer on the host computer by way of a
parallel port interface emulated in hardware.
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Floppy disk. The card uses the host computer’s 3.5-inch internal floppy drive.
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Hard Disk. The card has access to the host computer’s internal hard drive and
external SCSI devices.
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Keyboard and mouse. The card uses the host computer’s keyboard and mouse
through hardware emulation.
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Joystick. The monitor adapter cable includes a DB-15 connector that supports a
standard PC-style joystick.
The DOS Compatibility Card installed in a Power Macintosh 6100 computer provides
performance and features comparable with midrange 80486DX computers currently
available. Table 1-1 compares the features the two computers.
Table 1-1 Comparison of the DOS Compatibility Card and a midrange PC
Feature DOS Compatibility Card Midrange PC
Processor 66 MHz 80486DX2 Same
Network support IPX and TCP/IP Optional
Onboard RAM None 4 MB
Expansion RAM 1 SIMM (up to 32 MB) 8 SIMMs (up to 64 MB)
Video support VGA, EGA, CGA, MDA Same
Video RAM 512 KB DRAM Same
Sound card Sound out only Optional
Serial ports 2 (COM1 and COM2) Same
Parallel port 1 (emulated, XT/AT compatible) 1
Keyboard AT compatible Same
Mouse PS/2 compatible Same
continued