def make_file(filename,contents,file_options={})
raise "Tokenisation not currently supported for DOS files" if (file_options[:tokenise])
file_type = case file_options[:filetype]
when nil then 0x00
when 'T' then 0x00
when 'I' then 0x01
when 'A' then 0x02
when 'B' then 0x04
else file_options[:filetype].tr("$","").hex
end
if file_type==4 && !(file_options[:base].nil?) then
base=file_options[:base].tr("$","").hex
s="\0\0\0\0"
s[0]=base%256
s[1]=base/256
s[2]=contents.length%256
s[3]=contents.length/256
contents=s+contents
end
new_file=DOSFile.new(filename,contents,false,file_type)
return new_file
end