8211 Parallel Interface

8211 is simple parallel interface used in some ISA cards for 8088 PC and controls one LPT port.

8237

Newer version of 8257 DMA. See below.

8250 UART

8250 uses 8 addresses of ports, controls 3 ouput and 5 input lines, maximal speed is 115200bps. There are also newer versons with FIFO buffers and speed increased to 500kbps

This UART is used mostly in 8088 PC design.

8251 USART

8251 Universal Synchronous/Asynchronous Receiver/Transmitter uses 2 port addresses and needs external clock generator (usually 8253).

Used in MSX as serial interface together with 8253, also in Timex 2050 modem.

8253

8253 is programmable divider/counter.

Used in MSX as RS232 clock, in 8088 PC as sound and DMA generator, in Byte (ZX Spectrum clone) as sound generator.

8255 PPI

8255 Programmable Parallel Interface uses 4 addresses of ports and controls 24 parallel lines that can be configured as inputs or outputs (in groups of 8+8+4+4). Except basic MODE 0 (simply inputs and ouputs), there are rarely used MODE 1 (strobed input or output - can be used in printer as Centronics input) and MODE 2 (strobed bidirectional communication). MODE 1 and MODE 2 can generate interrupts. 8255A is newer, corrected version of 8255.

8255 PPI is probably the most popular interface chip that was used in computers: 8088 PC, MSX, Amstrad CPC, Elwro 800 Junior, 8051 microcontroller, and interfaces: for ZX Spectrum (MB-02, D40/D80, ZXATASP, ZXCF, as EPROM programmer, joystick & printer interface).

8257

8257 is DMA chip dedicated for 8080 CPU, used also in 8088 PC (or replaced with newer version 8237).

8259

8259 is interrupt priority manager. Used mainly in 8088 PC (two in PC AT).

8272

8272 is Single/Double Density Floppy Disk Controller, capable of using 2MB floppy disks. For details please see FDC 765A page.

Files for download

i8257.pdf 199.5kB (2005-08-23 00:51)

Datasheet for 8257 by Intel. PDF file created from TIFs available in Internet.

chipsi82c55a.pdf 325.1kB (2002-10-16 11:56)

Datasheet for 8255 by Intel (low power CMOS).

82c37.pdf 148.2kB (1999-08-09 13:19)

Datasheet for 82C37 by Intersil (newer version of 8257).

8211.txt 1.4kB (1992-07-28 23:01)

[??] 8211 pinout.

Links to other pages

See also

765A, 8272 Floppy Disk Controller

One of 2 most popular Floppy Disk Controler type - Intel 8272, also known as FDC765A.