From 5742e1f66c4e70151865de7092547223898bbf6b Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Sun, 18 Apr 2021 16:00:54 -0700
Subject: Support a proper PDP-8 assembler.

---
 asm.rb | 70 ------------------------------------------------------------------
 1 file changed, 70 deletions(-)
 delete mode 100755 asm.rb

(limited to 'asm.rb')

diff --git a/asm.rb b/asm.rb
deleted file mode 100755
index 6da40fb..0000000
--- a/asm.rb
+++ /dev/null
@@ -1,70 +0,0 @@
-#!/usr/bin/ruby -w
-
-OPCODES = {
-  "i"     => 0x080,
-  "acc="  => 0x100,
-  "ladd"  => 0x200,
-  "store" => 0x300,
-  "ifeq"  => 0x400,
-  "jmp"   => 0x500,
-  "ascii" => 0x600,
-  "cla"   => 0x001,
-  "++acc" => 0x002,
-  "--acc" => 0x004,
-  "tx"    => 0x040,
-  "rx"    => 0x080,
-  "halt"  => 0x000,
-  }
-
-Line = Struct.new(:opcode, :refs, :code)
-
-$labels = {}
-$code = []
-ARGF.each_line() do | line |
-  line.chomp!()
-  line.sub!(/^.*\/\/\s*/, "")
-  next unless line =~ /\S/
-  op = 0x000
-  refs = []
-  line.scan(/\S+/).each() do | word |
-    break if word =~ /^#/
-    if word =~ /^0(\d+)$/
-      op |= $1.to_i(8)
-    elsif word =~ /^-0(\d+)$/
-      op |= 0x100 - $1.to_i(8)
-    elsif word =~ /^(\d+)$/
-      op |= $1.to_i(10)
-    elsif word =~ /^-(\d+)$/
-      op |= 0x100 - $1.to_i(10)
-    elsif word =~ /^0x([0-9a-f]+)$/i
-      op |= $1.to_i(16)
-    elsif word =~ /^-0x([0-9a-f]+)$/i
-      op |= 0x100 - $1.to_i(16)
-    elsif OPCODES.key?(word)
-      op |= OPCODES[word]
-    elsif word =~ /^(.+):$/
-      $labels[$1] = $code.size()
-    else
-      refs << word
-    end
-  end
-  $code << Line.new(op, refs, line)
-end
-
-$code.each_with_index() do | line, i |
-  op = line.opcode
-  line.refs.each() do | ref |
-    if ref =~ /^@(.+)$/ and $labels.key?($1)
-      op |= $labels[$1]
-    elsif $labels.key?(ref)
-      target = $labels[ref] - (i + 1)
-      throw "Jump too far forward" if target > 0x7f
-      target += 0x80 if target < 0
-      throw "Jump too far backward" if target < 0
-      op |= target
-    else
-      throw "I don't understand #{ref.inspect()}"
-    end
-  end
-  $stdout.write("#{op.to_s(16).rjust(3, "0")} // #{line.code}\n")
-end
-- 
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