Hack #75. Let Windows Tell You About I/O Card Conflicts

Early SCSI adapters and sound cards arrived in the PC market at about the same time. With only the known IBM PC design reference to go by, and no industry-standards group to keep track of who was developing what devices, none of the designers of various devices knew what the others were doing. In the face of limited available resources, everyone scrambled to establish a foothold and hoped they didn't get trampled.

It was not uncommon to encounter a SCSI host adapter and a sound card that both used the same address (often 220h or 330h). Obviously if both adapters used the same address this combination would not work. If software addressed the sound card, it would wrongly get the attention of the SCSI host adapter; if software addressed the SCSI host adapter, it would wrongly get the attention of the sound card.

In such battles, the device with more clout wins, and such was the case with the sound card. Many more people were buying sound cards than were investing in expensive SCSI devices, so makers of the SCSI adapters moved off to address 330h and the sound card manufacturers held the ground at 220h.

You need to know which devices use which addresses and configure them so there is no direct conflict. To find out if you have any device conflicts and drill down to what they are, open Windows Device Manager. If you see a yellow dot with an exclamation point in it, you have a conflict. If you see a red x, the device is disabled. ...

Get PC Hacks now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.