This card provides the following extensions and changes to the Atari operating system:

• HIAS High Speed SIO that works with compatible devices. (i.e. Happy Enhancement)
• Fast Math F+ floating point math pack that, on the average, doubles the speed of floating point calculations that use the built-in floating point routines.
• Left screen margin set to 0.
• Reduced key repeat delay.
• Reduced key repeat rate.
• Option key function is inverted, at boot time, when configured with an even Device ID number.
• With PBI RAM installed, has the following additional features when Device ID is set to any number except 1 and 4: Attract mode is turned off, CONTROL/SHIFT/DELETE cold starts the computer, SHIFT/HELP toggles international character set, CONTROL/HELP sets left screen margin to 0, CONTROL/SHIFT/INVERSE starts WozMon, Atari Fuji Screen on entry to self test mode.

This card can be disabled by booting the computer with a Select key held down.

See the Atari 1090XL Expansion Card Instruction manual (Available as "Datasheet", below.) for more detailed instructions.

Please note this sale is for the card only and not for the 1090XL Expansion System and/or CP/M board that are also shown in some of the pictures.