M1.x & M1.55
The earliest Motronic petrol generation. M1.x covers the 32 KB, 68HC11-based BMW ECUs (M1.3 / M1.7); M1.55 is a transitional Alfa Romeo family on a Motorola 68K-derivative CPU with a 128 KB ROM. M1.55 is a separate extractor in OpenRemap, distinct from the ME1.5.5 family — see ME1.5.5.
| Era | 1987–2002 |
| File sizes | 32 KB (M1.x) / 128 KB (M1.55) |
| Variants | M1.3 (BMW ~1987–1993), M1.7 (BMW ~1989–1996), M1.55 (Alfa Romeo 155/156/GT/Spider — 2.0 TS, 1.8 TS, 2.5 V6, 1994–2002) |
| CPUs | Motorola 68HC11 (M1.x), Motorola 68K-derivative (M1.55) |
Detection
M1.x: 4-byte HC11 reset-vector magic (85 0a f0 30) plus the
"0000000M1.3 / "0000000M1.7 markers and reversed-digit ident. M1.55:
128 KB size gate plus the b"M1.55" family descriptor at 0x08005 (a
Motorola 68K reset-vector area, not the HC11 magic).
Checksums: no family profile.