ISA
ISA (Industry Standard Architecture) was een bus voor uitbreidingskaarten. De bus is 16 bits ontworpen maar heeft is de eerste 8 bits PC's, 8 bits uitgevoerd. vanaf de 80286 processor was de ISA bus 16 bits de bus werd hieraa ook wel AT bus genoemd. Bij het sneller worden van PC's bleek de ISA bus te traag werd voor grafische kaarten daarom werd de VESA Local bus (VLB) in het leven geroepen. Deze zorgde voor een snelle doorvoer van de grafische gegevens. IDE is inmiddels volledig verdrongen door PCI maar is nog lange tijd naast PCI gebruikt
Fig 1. ISA connector.
| Aansluitingen ISA connector | |||||
| A1 | -I/O CH CK | I | B1 | Ground | |
| A2 | SD7 | I/O | B2 | Reset Drive | O |
| A3 | SD6 | I/O | B3 | +5Vdc | |
| A4 | SD5 | I/O | B4 | IRQ9 | I |
| A5 | SD4 | I/O | B5 | -5Vdc | |
| A6 | SD3 | I/O | B6 | DRQ2 | I |
| A7 | SD2 | I/O | B7 | -12Vdc | |
| A8 | SD1 | I/O | B8 | 0 WS | I |
| A9 | SD0 | I/O | B9 | +12Vdc | |
| A10 | -I/O CH RDY | I | B10 | Ground | |
| A11 | AEN | O | B11 | -SMEMW | O |
| A12 | SA19 | I/O | B12 | -SMEMR | O |
| A13 | SA18 | I/O | B13 | -IOW | I/O |
| A14 | SA17 | I/O | B14 | -IOR | I/O |
| A15 | SA16 | I/O | B15 | -DACK3 | O |
| A16 | SA15 | I/O | B16 | DRQ3 | I |
| A17 | SA14 | I/O | B17 | -DACK1 | O |
| A18 | SA13 | I/O | B18 | DRQ1 | I |
| A19 | SA12 | I/O | B19 | -Refesh | I/O |
| A20 | SA11 | I/O | B20 | CLK | O |
| A21 | SA10 | I/O | B21 | IRQ7 | I |
| A22 | SA9 | I/O | B22 | IRQ6 | I |
| A23 | SA8 | I/O | B23 | IRQ5 | I |
| A24 | SA7 | I/O | B24 | IRQ4 | I |
| A25 | SA6 | I/O | B25 | IRQ3 | I |
| A26 | SA5 | I/O | B26 | -DACK2 | O |
| A27 | SA4 | I/O | B27 | T/C | O |
| A28 | SA3 | I/O | B28 | BALE | O |
| A29 | SA2 | I/O | B29 | +5Vdc | |
| A30 | SA1 | I/O | B30 | OSC | O |
| A31 | SA0 | I/O | B31 | Ground | |
| C1 | SBHE | I/O | D1 | -MEM | I |
| C2 | LA23 | I/O | D2 | -I/O | I |
| C3 | LA22 | I/O | D3 | IRQ10 | I |
| C4 | LA21 | I/O | D4 | IRQ11 | I |
| C5 | LA20 | I/O | D5 | IRQ12 | I |
| C6 | LA19 | I/O | D6 | IRQ15 | I |
| C7 | LA18 | I/O | D7 | IRQ14 | O |
| C8 | LA17 | I/O | D8 | -DA | O |
| C9 | -MEMR | I/O | D9 | DRQ0 | I |
| C10 | -MEMW | I/O | D10 | -DA | O |
| C11 | SD8 | I/O | D11 | DRQ5 | I |
| C12 | SD9 | I/O | D12 | -DA | O |
| C13 | SD10 | I/O | D13 | DRQ6 | I |
| C14 | SD11 | I/O | D14 | -DA | O |
| C15 | SD12 | I/O | D15 | DRQ7 | I |
| C16 | SD13 | I/O | D16 | +5Vd | C |
| C17 | SD14 | I/O | D17 | -Master | I |
| C18 | SD15 | I/O | D18 | Ground | |