A version of Adobe Type Manager requiring at least Mac OS 7.01 and a 68020 CPU is available elsewhere in Macintosh Garden. The present download is a much earlier version of ATM that is compatible with a 68000 CPU and System 6, as well as Mac OS 7. It supports PostScript Type 1, TrueType fonts, and 32 bit addressing. The download is a Disk Copy 4.2 image of the floppy disk, compressed with MacZip (use the same to uncompress). The screenshot is of a floppy disk for a still earlier version that I no longer have.
Should work with Mac OS 6 and 7. I have verified that Mac OS 6.0.8 on MinivMac will boot without incident with ATM 2.0.3 installed. Likewise, it seems OK with Mac OS 7.5.5 on a 68040 but ATM 2.0.3 does not have a 68040 driver (only 68000, 68020, 68030) and I have not tested it fully.