If you purchase Cro-Mags' two latest CD's
(Hard Times in an Age of Quarrel
and Age of Quarrel/Best Wishes)
you'll find some sort of preface. These two prefaces are now online. You can read about their history and their problems.
In short; you'll be a step closer to understanding the beginning of HardCore. Enjoy!
Steve Blushe's (NYC) introduction to the Age of Quarrel/Best Wishes release
Onno Cromag's (Netherlands) introduction to the Hard Times in an Age of Quarrel (live) release
"History of the Cro-Mags" by Mark (Canada)