Appendix — Glossary

Term	Meaning
A2L	ASAM MCD-2 MC definition file; pins down address, size and scaling.
Axis	The physical meaning of a map's rows/columns.
Byte order	The order in which the bytes of a cell are stored.
Checksum	Integrity value inside the ROM; recalculated after changes.
COMPU_METHOD	A2L rule for converting to a physical value.
Container	The project format keeping ROM, maps, history and metadata in one file (.mtrp).
Curve	One-dimensional map; type CURVE.
Differences	Panel listing the differences between two versions/ROMs.
Linked ROM	A reference ROM attached to the project for comparison.
Limp mode	The ECU's protective state after a failed integrity check.
Map	A table of adjacent bytes in the ROM.
MTRP	Magic value / format name of the project container.
Offset	The additive part of a scaling rule.
Patch	File carrying specific byte/map changes (.mtrpatch).
Physical domain	Values after scaling has been applied — what you see.
Scaling	Factor and offset that convert a raw byte to a physical value.
Slider limits	The range outside which cell values may not move.
Snapshot	The complete project state at one moment; a return point.
SOI	Start Of Image — the beginning of a data block in A2L.
TOC	Block directory inside the project container.
Value map	Single-cell (1×1) scaling or setting value.
Cursor sync	Keeps two compared views on the same row.

Abbreviations

Short	Meaning
ECU	Electronic Control Unit
ROM	Read Only Memory — the flash holding the ECU software
DTC	Diagnostic Trouble Code
RAM	The ECU's working memory
STD_AXIS	Standard, evenly spaced axis definition
COM_AXIS	Common-reference (irregular) axis definition
MSB_FIRST	Most significant byte first (big endian)
MSB_LAST	Least significant byte first (little endian)

Common map-name patterns

Pattern	Usually indicates
DKAT* / KAT*	Catalyst monitoring thresholds
LDRXN*, LDR*	Load / boost request maps
N_LIMIT*	Rev limiter
VMAX*	Speed limiter
AGR*	EGR flow / valve position maps
DPF*	Diesel particulate filter pressure / soot
KRKTE*	Fuel correction (lambda/cycle) maps

Tip

Do not trust these patterns blindly: always open the search results and check the map's dimensions and axes first. The same name can mean something different in another ROM.