YES. Sounds like that is what you did. If you depress the ISO button on the left and rotate the left control wheel you have forced the ISO setting to override the automatic DX setting. Once you do that, the ISO speed will remain set regardless of the DX code on the film you load. The 90s manual states you can change that to DX priority with the Photo Secretary but I do not have one. To return the 90s to Automatic DX ISO mode, depress the left ISO button and rotate the right wheel until you get to the DX speed of the film you have loaded, which will turn on the DX indicator in the LCD.
