<Table> IBM Personal Computer <Tr> <Td_colspan="2"> IBM 5150 PC with IBM 5151 monitor </Td> </Tr> </Table> <Tr> <Td_colspan="2"> IBM 5150 PC with IBM 5151 monitor </Td> </Tr> <Table> The IBM PC line <Tr> <Th> Model name </Th> <Th> Model #</Th> <Th> Introduced </Th> <Th> CPU </Th> <Th> Features </Th> </Tr> <Tr> <Td> PC </Td> <Td> 5150 </Td> <Td> August 1981 </Td> <Td> 8088 </Td> <Td> Floppy disk or cassette system . One or two internal floppy drives were optional . </Td> </Tr> <Tr> <Td> XT </Td> <Td> 5160 </Td> <Td> March 1983 </Td> <Td> 8088 </Td> <Td> First IBM PC to come with an internal hard drive as standard . </Td> </Tr> <Tr> <Td> XT / 370 </Td> <Td> 5160 / 588 </Td> <Td> October 1983 </Td> <Td> 8088 </Td> <Td> 5160 with XT / 370 Option Kit and 3277 Emulation Adapter </Td> </Tr> <Tr> <Td> 3270 PC </Td> <Td> 5271 </Td> <Td> October 1983 </Td> <Td> 8088 </Td> <Td> With 3270 terminal emulation, 20 function key keyboard </Td> </Tr> <Tr> <Td> PCjr </Td> <Td> 4860 </Td> <Td> November 1983 </Td> <Td> 8088 </Td> <Td> Floppy - based home computer, but also used ROM cartridges; infrared keyboard </Td> </Tr> <Tr> <Td> Portable </Td> <Td> 5155 </Td> <Td> February 1984 </Td> <Td> 8088 </Td> <Td> Floppy - based portable </Td> </Tr> <Tr> <Td> AT </Td> <Td> 5170 </Td> <Td> August 1984 </Td> <Td> 80286 </Td> <Td> Faster processor, faster system bus (6 MHz, later 8 MHz, vs 4.77 MHz), jumperless configuration, real - time clock </Td> </Tr> <Tr> <Td> AT / 370 </Td> <Td> 5170 / 599 </Td> <Td> October 1984 </Td> <Td> 80286 </Td> <Td> 5170 with AT / 370 Option Kit and 3277 Emulation Adapter </Td> </Tr> <Tr> <Td> 3270 AT </Td> <Td> 5281 </Td> <Td> June 1985 </Td> <Td> 80286 </Td> <Td> With 3270 terminal emulation </Td> </Tr> <Tr> <Td> Convertible </Td> <Td> 5140 </Td> <Td> April 1986 </Td> <Td> 80C88 </Td> <Td> Microfloppy laptop portable </Td> </Tr> <Tr> <Td> XT 286 </Td> <Td> 5162 </Td> <Td> September 1986 </Td> <Td> 80286 </Td> <Td> Slow hard disk, but zero wait state memory on the motherboard . This 6 MHz machine was actually faster than the 8 MHz ATs (when using planar memory) because of the zero wait states </Td> </Tr> </Table> <Tr> <Th> Model name </Th> <Th> Model #</Th> <Th> Introduced </Th> <Th> CPU </Th> <Th> Features </Th> </Tr>

When did ibm introduced the 80286 based pc/at
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