8288 bus controller pinout
DIP-20. Makes the memory and I/O strobes and the bus direction for the 8088 in maximum mode.
Decodes the 8088 status lines /S0 to /S2 into the command strobes, plus ALE, DEN, DT/R and /INTA. It is bipolar and runs warm. On the 5150 (U6) the bus write strobes come from the advanced outputs AMWC and AIOWC; MWTC and IOWC are not connected, and IOB is tied LOW (system bus mode). Also on the 5150: ALE goes to I/O channel pin B28, /AEN is driven by AEN BRD from the DMA logic, and MCE/PDEN is not connected. A dead 8288 means no ROM reads and no beep.
Open the interactive 8288 pinoutPins
| Pin | Name | Type | Signal |
|---|---|---|---|
| 1 | IOB | ctrl | I/O bus mode strap. HIGH: I/O bus mode. LOW: system bus mode. 5150: tied to GND. UNVERIFIED |
| 2 | CLK | clock | Clock from the 8284A CLK output. Times the command outputs. |
| 3 | /S1 | ctrl | Status /S1 from the 8088 (pin 27). All three status lines HIGH means passive. |
| 4 | DT/R | ctrl | Data transmit (HIGH, a write) or receive (LOW, a read). Sets the transceiver direction. |
| 5 | ALE | ctrl | Address latch enable, active HIGH. The address latches on its falling edge. |
| 6 | /AEN | ctrl | Address enable, active LOW. Enables the command outputs at least 115 ns after it goes LOW; going HIGH floats them at once. |
| 7 | /MRDC | ctrl | Memory read command, active LOW. |
| 8 | /AMWC | ctrl | Advanced memory write command, active LOW. Same timing as a read command, earlier than MWTC. |
| 9 | /MWTC | ctrl | Memory write command, active LOW. |
| 10 | GND | ground | Ground. |
| 11 | /IOWC | ctrl | I/O write command, active LOW. |
| 12 | /AIOWC | ctrl | Advanced I/O write command, active LOW. Earlier than IOWC. |
| 13 | /IORC | ctrl | I/O read command, active LOW. |
| 14 | /INTA | ctrl | Interrupt acknowledge, active LOW. Tells the 8259A to put its vector on the bus. |
| 15 | CEN | ctrl | Command enable. HIGH enables the commands and DEN; LOW forces them inactive. 5150: driven by /AEN, so DMA cycles turn the 8288 commands off. UNVERIFIED |
| 16 | DEN | ctrl | Data enable, active HIGH. Turns on the data transceivers. |
| 17 | MCE/PDEN | ctrl | IOB LOW: master cascade enable (HIGH) for a cascaded 8259A. IOB HIGH: peripheral data enable (LOW). |
| 18 | /S2 | ctrl | Status /S2 from the 8088 (pin 28). |
| 19 | /S0 | ctrl | Status /S0 from the 8088 (pin 26). |
| 20 | VCC | power | +5 V supply. |