The Adapter is a mechanical part that connects the emulator to a target board. This is a small board with a couple of connectors on the top to stack the emulator POD and a special header or spacer on the bottom that fits into the target socket. DIP, PLCC, QFP, SOIC and other types of the adapters are available or are under development.
The Adapter abbreviation includes (from left to right) the "A" letter (means Adapter), the target MCU family code (051) following a dash sign, the chip package code (for example "D" means DIP, "L" means PLCC), the number of the chip pins (20, 40, 44, 68, etc) sometimes following a slash sign and a code of the matching POD group (/AT, etc.). For example, the A051-L44 adapter supports all 8051 microcontrollers in 44-pin PLCC packages; the A051-D20/AT means 20-pin DIP adapter for the low pin count Atmel MCU family (AT89Cx051).
Adapters for emulating microcontrollers in SOIC packages are comprised of two parts - a DIP adapter (for example A051-D24) and additional adapter DIP-SOIC (for example PA-DS-2403). The last adapter also includes a part soldering on the target board instead of the target socket.
In order to find all the adapters available for the emulator click on the more info button. Select the target MCU type and locate the adapter you need.