diff --git a/devel/dasm/Makefile b/devel/dasm/Makefile
new file mode 100644
index 00000000000..d1f9a10e79d
--- /dev/null
+++ b/devel/dasm/Makefile
@@ -0,0 +1,27 @@
+# $OpenBSD: Makefile,v 1.1.1.1 2021/01/15 15:01:36 gonzalo Exp $
+
+COMMENT=		versatile macro assembler for 8-bit microprocessors
+
+GH_ACCOUNT=		dasm-assembler
+GH_PROJECT=		dasm
+GH_TAGNAME=		2.20.14
+
+CATEGORIES=		devel
+
+MAINTAINER=		Gonzalo L. R. <gonzalo@openbsd.org>
+
+# GPLv2
+PERMIT_PACKAGE= Yes
+
+WANTLIB += c
+
+WRKDIST=		${WRKDIR}/${PKGNAME}
+
+post-install:
+	${INSTALL_DATA_DIR} $(PREFIX)/share/doc/dasm
+	${INSTALL_DATA} ${WRKSRC}/docs/sources/*.tex $(PREFIX)/share/doc/dasm
+	${INSTALL_DATA_DIR} $(PREFIX)/share/doc/dasm/images
+	${INSTALL_DATA} ${WRKSRC}/docs/sources/images/illegal.png $(PREFIX)/share/doc/dasm/images
+	${INSTALL_DATA} ${WRKSRC}/docs/dasm.pdf $(PREFIX)/share/doc/dasm
+
+.include <bsd.port.mk>
diff --git a/devel/dasm/distinfo b/devel/dasm/distinfo
new file mode 100644
index 00000000000..efbdaaf4449
--- /dev/null
+++ b/devel/dasm/distinfo
@@ -0,0 +1,2 @@
+SHA256 (dasm-2.20.14.tar.gz) = xmU4rYxBOk6ohSUkbtn+8r+cnS42WTrN9lHgZjWtdJc=
+SIZE (dasm-2.20.14.tar.gz) = 989739
diff --git a/devel/dasm/patches/patch-Makefile b/devel/dasm/patches/patch-Makefile
new file mode 100644
index 00000000000..bb85bdb1a33
--- /dev/null
+++ b/devel/dasm/patches/patch-Makefile
@@ -0,0 +1,41 @@
+$OpenBSD: patch-Makefile,v 1.1.1.1 2021/01/15 15:01:36 gonzalo Exp $
+
+Index: Makefile
+--- Makefile.orig
++++ Makefile
+@@ -33,7 +33,9 @@ all: build
+ 
+ # install, currently not implemented
+ install: build
+-	echo "Installation not implemented, you're on your own, sorry."
++	install -m 0755 src/dasm $(PREFIX)/bin/dasm
++	install -m 0755 src/ftohex $(PREFIX)/bin/ftohex
++	
+ 
+ # just run all the tests
+ test: build
+@@ -78,23 +80,10 @@ TSTS=test/*.asm test/*.bin.ref test/*.hex.ref test/Mak
+ # other files
+ OTHS=Makefile
+ 
+-ifeq ($(strip $(BINARY)),)
+-# source release, no binaries
+-CONTENTS=$(DOCS) $(MACS) $(SRCS) $(TSTS) $(OTHS)
+-DIRNAME=dasm-$(RELEASE)
+-ZIPNAME=dasm-$(RELEASE)
+-else
+-# binary release for specific platform
+-CONTENTS=$(BINS) $(DOCS) $(MACS) $(SRCS) $(TSTS) $(OTHS)
+-DIRNAME=dasm-$(RELEASE)
+-ZIPNAME=dasm-$(RELEASE)-$(BINARY)
+-endif
+-
+ # create a distribution archive for publication 
+ dist: build
+ 	mkdir $(DIRNAME)
+-	cp -p -r --parents $(CONTENTS) $(DIRNAME)
+-	tar cvf - $(DIRNAME) | gzip -9 >$(ZIPNAME).tar.gz
++	cp -r $(CONTENTS) $(DIRNAME)
+ #	tar cvf - $(DIRNAME) | bzip2 -9 >$(ZIPNAME).tar.bz2
+ 	rm -rf $(DIRNAME)
+ 
diff --git a/devel/dasm/patches/patch-src_Makefile b/devel/dasm/patches/patch-src_Makefile
new file mode 100644
index 00000000000..edba7449e71
--- /dev/null
+++ b/devel/dasm/patches/patch-src_Makefile
@@ -0,0 +1,15 @@
+$OpenBSD: patch-src_Makefile,v 1.1.1.1 2021/01/15 15:01:36 gonzalo Exp $
+
+Index: src/Makefile
+--- src/Makefile.orig
++++ src/Makefile
+@@ -61,7 +61,8 @@ all: $(ALL)
+ dasm: $(OBJS)
+ 	$(CC) $(OBJS) -o dasm $(LDFLAGS)
+ 
+-ftohex: ftohex.o
++ftohex:
++	$(CC) ftohex.c -o ftohex $(LDFLAGS)
+ 
+ obj: $(OBJS)
+ 
diff --git a/devel/dasm/patches/patch-test_run_tests_sh b/devel/dasm/patches/patch-test_run_tests_sh
new file mode 100644
index 00000000000..9589fd289ff
--- /dev/null
+++ b/devel/dasm/patches/patch-test_run_tests_sh
@@ -0,0 +1,20 @@
+$OpenBSD: patch-test_run_tests_sh,v 1.1.1.1 2021/01/15 15:01:36 gonzalo Exp $
+
+Index: test/run_tests.sh
+--- test/run_tests.sh.orig
++++ test/run_tests.sh
+@@ -1,4 +1,4 @@
+-#!/usr/bin/env bash
++#!/bin/sh
+ 
+ # Simple test script adapted from Matt Dillon's 2.16  release.
+ # It's harder to do this in a Makefile, so let's use a script.
+@@ -71,7 +71,7 @@ do
+ 	    then
+ 		echo "		file [$NAME.hex.ref] missing	FAILED!" 
+ 	    else
+-		diff -bBduw $NAME.hex $NAME.hex.ref >$NAME.hex.diff
++		diff -bduw $NAME.hex $NAME.hex.ref >$NAME.hex.diff
+ 		echo "		binaries differ	FAILED!" 
+ 	    fi
+ 	    fail="$[$fail+1]"
diff --git a/devel/dasm/pkg/DESCR b/devel/dasm/pkg/DESCR
new file mode 100644
index 00000000000..af0aa086e94
--- /dev/null
+++ b/devel/dasm/pkg/DESCR
@@ -0,0 +1,3 @@
+DASM, a versatile macro assembler with support for several 8-bit
+microprocessors including MOS 6502 & 6507; Motorola 6803, 68705, and 68HC11;
+Hitachi HD6303 (extended Motorola 6801) and Fairchild F8.
diff --git a/devel/dasm/pkg/PLIST b/devel/dasm/pkg/PLIST
new file mode 100644
index 00000000000..a260f31aabe
--- /dev/null
+++ b/devel/dasm/pkg/PLIST
@@ -0,0 +1,24 @@
+@comment $OpenBSD: PLIST,v 1.1.1.1 2021/01/15 15:01:36 gonzalo Exp $
+@bin bin/dasm
+@bin bin/ftohex
+share/doc/dasm/
+share/doc/dasm/6502.tex
+share/doc/dasm/6803.tex
+share/doc/dasm/68705.tex
+share/doc/dasm/68HC11.tex
+share/doc/dasm/ChannelF.tex
+share/doc/dasm/F8.tex
+share/doc/dasm/HD6303.tex
+share/doc/dasm/changelog.tex
+share/doc/dasm/dasm.pdf
+share/doc/dasm/dasm.tex
+share/doc/dasm/images/
+share/doc/dasm/images/illegal.png
+share/doc/dasm/introduction.tex
+share/doc/dasm/legal.tex
+share/doc/dasm/machines.tex
+share/doc/dasm/manual.tex
+share/doc/dasm/mc68hc908.tex
+share/doc/dasm/preface.tex
+share/doc/dasm/processor6502.tex
+share/doc/dasm/titlepage.tex