Specifications

Computer Architecture and Maintenance (G-Scheme-2014)
 Coprocessor speed 4 or 5.33MHz
 Standard graphics None standard
 RS232C serial ports 1 (some models)
 UART chip used NS16450
 Maximum speed (bits per second) 9,600bps
 Maximum number of ports supported 2
 Pointing device (mouse) ports None standard
 Parallel printer ports 1 (some models)
 Bidirectional Yes
 Maximum number of ports supported 3
 CMOS real-time clock (RTC) Yes
 CMOS RAM 64 bytes
 Battery life 5 years
Expansion Slots
 Total adapter slots 8
 Number of long and short slots 8/0
 Number of 8-/16-/32-bit slots 2/6/0
 Available slots (with video) 5
Q.Differences Between PC/XT and AT Systems
Ans.
Systems that feature an 8-bit memory bus are called PC/XT systems after the pioneering
IBM PC and IBM PC/XT. As you can see in Table 2.2, the differences between these
systems and descendents of the IBM AT (16-bit memory bus and above) are significant.
All modern systems fall into the AT category.
Table . Differences Between PC/XT and AT Systems
System Attributes
PC/XT Type 8-Bit 16-, 32-, 64-Bit AT Type
Supported processors All x86 or x88 286 or higher
Processor modes Real Real, Protected, Virtual Real[2]
Software supported 16-bit only 16- or 32-bit[2]
Bus slot width 8-bit 16-, 32-[1], and 64-bit[4]
Slot type ISA only ISA, EISA[1], MCA, PC Card, Cardbus[3], VL-
Bus[3], PCI[3], AGP[4]
Hardware interrupts 8 (6 usable) 16 (11 usable)
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
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