Denise

DENISE is a contrived contraction of Display ENabler.

In the early days of the Amiga 1000 and Amiga 500, it was often called Daphne.  There is no functional difference, asides from the early revisions (8362 R5) being unable to display the EHB graphic mode.

Early revisions of DENISE (8362 R5) were unable to display the EHB graphic mode.

In the OCS and ECS machines, DENISE uses a DMA channel to retrieve the display data from AGNUS, and outputs a data stream ready to be displayed on a TV screen or monitor.  DENISE also reads in the axis information from mice and joysticks.  It is also responsible for displaying any sprites being used.  DENISE was replaced by the LISA Chip in the AGA Chipset.

DENISE is sometimes known as “Super DENISE” (Amiga 500Plus, Amiga 600, Amiga 2000) or “Fat DENISE” (Amiga 3000, 8373 R4)  to differentiate from the original chips, these are the ECS versions of DENISE.  These later versions of DENISE were capable of a greater range of screen display resolutions and scan rates.  While the original DENISE chips could only output a standard NTSC (60Hz, 15kHz) or PAL (50Hz, 15kHz) display, the later ECS DENISE chips were far more flexible, although this was only really useful to those with displays capable of displaying higher refresh rates, such as “multisync” monitors, such as the Commodore 1942.

As is so often the case with the Amiga range, there was an exception, the Amiga 3000 and Amiga 3000 Tower machines, or Amiga 2000Amiga 4000 or Amiga 4000 Tower machines fitted with the A2320 Amber card, could display 15kHz display modes on screens that could only display 31kHz signals.

Earlier versions of the DENISE chip can be replaced with later versions, as they are pin compatible, and when used with an upgraded AGNUS, provide the enhanced graphics output modes of the ECS chipset.