DAMOS (Data Model for Automotive Systems) is an older, proprietary format originally developed by Bosch. It describes the maps, curves, and parameters of an ECU calibration: map name, memory address in the binary, data type (uint8, int16, uint32...), scaling factor, offset, physical unit, X and Y axis references.
DAMOS files are typically only available within the Bosch/OEM ecosystem and are not officially shared. Some DAMOS information can be found indirectly in tool databases (KESS, CMD, Autotuner) as tool manufacturers have invested their own reverse engineering work.
A2L is the standardised successor — defined in the ASAP2 standard (Association for Standardisation of Automation and Measuring Systems, now ASAM). The format is more open and is also used in ECU domains beyond Bosch. An A2L file is a human-readable text file (ASCII) that describes all measurable and adjustable quantities of the ECU in structured blocks.
A typical A2L entry for a map contains: the symbolic name (e.g. ENG_TqMaxEngSpc), the memory address relative to the binary base address, the record layout (how rows and columns are arranged in memory), the conversion formula (physical value = internal value × factor + offset), and references to the axis descriptions.
Without scaling information, a map value is useless. A raw value of 0x4E20 (20000 decimal) could mean, depending on scaling: 20000 rpm (nonsensical), 2000 rpm (factor 0.1), 200.00 bar (factor 0.01), or 4.88 mg/stroke (factor 0.000244). Only the A2L/DAMOS scaling information makes the value interpretable. Scaling errors are a common source of mistakes in manual hex edits.
WinOLS can directly import A2L files and automatically assigns the correct name, unit, and scaling to every recognised data point. Without A2L, WinOLS works in "blind mode" and attempts to detect maps independently — with good results for known ECU types, but significantly more effort for new or exotic ECUs.
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