Green’s Dictionary of Slang

1. (also bamalam) low-grade marijuana.

1959		Murtagh & Harris Who Live In Shadow (1960) 88: Their prices vary [...] one dollar for three ‘Bams,’ weak marijuana cigarettes.
1973		L. Bangs in Psychotic Reactions (1988) 117: The very same fascist nebbishes that keep you from [...] smokin’ your bamalam.

2. (also bamm) amphetamine.

1969		R.R. Lingeman Drugs from A to Z (1970) 36: bam [...] Amphetamine pill, or amphetamine for injection.
1972		J. Mills Report to the Commissioner 103: Pat says, ‘I’m lookin’ for bams’ Bams are glass ampules of an amphetamine junkies like to mix with heroin.
1980		Chronicle-Telegram (Elyria, OH) 18 June 1/1: ‘Bamms’ are the street name of Preludin, a powerful amphetamine-type stimulant.

3. a barbiturate/amphetamine mix.

1971		E.E. Landy Underground Dict. (1972).
2001		ONDCP Street Terms 2: Bam — Amphetamine; depressants.