diff --git a/matlab/test/test_fiff_finish_writing_raw.m b/matlab/test/test_fiff_finish_writing_raw.m
new file mode 100644
index 0000000..0d5b5c9
--- /dev/null
+++ b/matlab/test/test_fiff_finish_writing_raw.m
@@ -0,0 +1,45 @@
+function test_suite=test_fiff_finish_writing_raw
+    try test_functions=localfunctions(); catch
+    end
+    initTestSuite;
+
+function test_fiff_readwrite_raw_()
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
+
+FIFF = fiff_define_constants;
+
+% read
+pathstr = fileparts(mfilename('fullpath'));
+fname   = fullfile(pathstr, 'data', 'test_raw.fif');
+info    = fiff_read_meas_info(fname);
+raw     = fiff_setup_read_raw(fname);
+[data, times] = fiff_read_raw_segment(raw);
+
+% write -> note that the original data was in 24 chunks of 600 samples, the
+% data is saved out as a single chunk of 14400 samples
+fnamenew = strrep(fname, 'test_', 'testout_');
+[outfid, cals] = fiff_start_writing_raw(fnamenew, info);
+fiff_write_int(outfid, FIFF.FIFF_FIRST_SAMPLE, raw.first_samp);
+fiff_write_int(outfid, FIFF.FIFF_DATA_SKIP, 0);
+fiff_write_raw_buffer(outfid, data, cals);
+fiff_finish_writing_raw(outfid);
+
+% read the new file
+rawnew     = fiff_setup_read_raw(fnamenew);
+[datanew, timesnew] = fiff_read_raw_segment(rawnew);
+
+% compare
+assertEqual(data,  datanew);
+assertEqual(times, timesnew);
+
+% clean up
+delete(fnamenew);
+
diff --git a/matlab/test/test_fiff_read_meas_info.m b/matlab/test/test_fiff_read_meas_info.m
new file mode 100644
index 0000000..e0a1a67
--- /dev/null
+++ b/matlab/test/test_fiff_read_meas_info.m
@@ -0,0 +1,45 @@
+function test_suite=test_fiff_read_meas_info
+    try test_functions=localfunctions(); catch
+    end
+    initTestSuite;
+
+function test_fiff_readwrite_raw_()
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
+
+FIFF = fiff_define_constants;
+
+% read
+pathstr = fileparts(mfilename('fullpath'));
+fname   = fullfile(pathstr, 'data', 'test_raw.fif');
+info    = fiff_read_meas_info(fname);
+raw     = fiff_setup_read_raw(fname);
+[data, times] = fiff_read_raw_segment(raw);
+
+% write -> note that the original data was in 24 chunks of 600 samples, the
+% data is saved out as a single chunk of 14400 samples
+fnamenew = strrep(fname, 'test_', 'testout_');
+[outfid, cals] = fiff_start_writing_raw(fnamenew, info);
+fiff_write_int(outfid, FIFF.FIFF_FIRST_SAMPLE, raw.first_samp);
+fiff_write_int(outfid, FIFF.FIFF_DATA_SKIP, 0);
+fiff_write_raw_buffer(outfid, data, cals);
+fiff_finish_writing_raw(outfid);
+
+% read the new file
+rawnew     = fiff_setup_read_raw(fnamenew);
+[datanew, timesnew] = fiff_read_raw_segment(rawnew);
+
+% compare
+assertEqual(data,  datanew);
+assertEqual(times, timesnew);
+
+% clean up
+delete(fnamenew);
+
diff --git a/matlab/test/test_fiff_read_tag.m b/matlab/test/test_fiff_read_tag.m
index 7a31f66..12b07a2 100644
--- a/matlab/test/test_fiff_read_tag.m
+++ b/matlab/test/test_fiff_read_tag.m
@@ -4,8 +4,46 @@
     initTestSuite;
 
 function test_fiff_read_tag_()
-% Test fiff_read_tag.m
-%
-% This is a placeholder function, referencing the below test function,
-% which should fail if fiff_read_tag does not work properly
-test_fiff_open
+% Test fiff_open.m
+
+if ispc
+  % I don't know what happens with the unit testing actually, if the
+  % function returns without actually testing anything
+  return;
+end
+
+f = which('test_fiff_define_constants.m');
+[p,f,e] = fileparts(f);
+
+% load the reference trees
+load(fullfile(p, 'data', 'test_fiftrees_ref.mat'));
+
+fname = fullfile(p, 'data', 'test_raw.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.raw));
+
+fname = fullfile(p, 'data', 'test_long_raw.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.longraw));
+
+fname = fullfile(p, 'data', 'test_raw-eve.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.raweve));
+
+fname = fullfile(p, 'data', 'test-eve.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.eve));
+
+fname = fullfile(p, 'data', 'test-ave.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.ave));
+
+fname = fullfile(p, 'data', 'test-cov.fif');
+[fid, tree, dir] = fiff_open(fname);
+fclose(fid);
+assert(isequal(tree, trees.cov));
diff --git a/matlab/test/test_fiff_start_writing_raw.m b/matlab/test/test_fiff_start_writing_raw.m
new file mode 100644
index 0000000..a8a7073
--- /dev/null
+++ b/matlab/test/test_fiff_start_writing_raw.m
@@ -0,0 +1,45 @@
+function test_suite=test_fiff_start_writing_raw
+    try test_functions=localfunctions(); catch
+    end
+    initTestSuite;
+
+function test_fiff_readwrite_raw_()
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
+
+FIFF = fiff_define_constants;
+
+% read
+pathstr = fileparts(mfilename('fullpath'));
+fname   = fullfile(pathstr, 'data', 'test_raw.fif');
+info    = fiff_read_meas_info(fname);
+raw     = fiff_setup_read_raw(fname);
+[data, times] = fiff_read_raw_segment(raw);
+
+% write -> note that the original data was in 24 chunks of 600 samples, the
+% data is saved out as a single chunk of 14400 samples
+fnamenew = strrep(fname, 'test_', 'testout_');
+[outfid, cals] = fiff_start_writing_raw(fnamenew, info);
+fiff_write_int(outfid, FIFF.FIFF_FIRST_SAMPLE, raw.first_samp);
+fiff_write_int(outfid, FIFF.FIFF_DATA_SKIP, 0);
+fiff_write_raw_buffer(outfid, data, cals);
+fiff_finish_writing_raw(outfid);
+
+% read the new file
+rawnew     = fiff_setup_read_raw(fnamenew);
+[datanew, timesnew] = fiff_read_raw_segment(rawnew);
+
+% compare
+assertEqual(data,  datanew);
+assertEqual(times, timesnew);
+
+% clean up
+delete(fnamenew);
+
diff --git a/matlab/test/test_fiff_write_int.m b/matlab/test/test_fiff_write_int.m
new file mode 100644
index 0000000..43b8016
--- /dev/null
+++ b/matlab/test/test_fiff_write_int.m
@@ -0,0 +1,45 @@
+function test_suite=test_fiff_write_int
+    try test_functions=localfunctions(); catch
+    end
+    initTestSuite;
+
+function test_fiff_readwrite_raw_()
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
+
+FIFF = fiff_define_constants;
+
+% read
+pathstr = fileparts(mfilename('fullpath'));
+fname   = fullfile(pathstr, 'data', 'test_raw.fif');
+info    = fiff_read_meas_info(fname);
+raw     = fiff_setup_read_raw(fname);
+[data, times] = fiff_read_raw_segment(raw);
+
+% write -> note that the original data was in 24 chunks of 600 samples, the
+% data is saved out as a single chunk of 14400 samples
+fnamenew = strrep(fname, 'test_', 'testout_');
+[outfid, cals] = fiff_start_writing_raw(fnamenew, info);
+fiff_write_int(outfid, FIFF.FIFF_FIRST_SAMPLE, raw.first_samp);
+fiff_write_int(outfid, FIFF.FIFF_DATA_SKIP, 0);
+fiff_write_raw_buffer(outfid, data, cals);
+fiff_finish_writing_raw(outfid);
+
+% read the new file
+rawnew     = fiff_setup_read_raw(fnamenew);
+[datanew, timesnew] = fiff_read_raw_segment(rawnew);
+
+% compare
+assertEqual(data,  datanew);
+assertEqual(times, timesnew);
+
+% clean up
+delete(fnamenew);
+
diff --git a/matlab/test/test_fiff_write_raw_buffer.m b/matlab/test/test_fiff_write_raw_buffer.m
new file mode 100644
index 0000000..5150a9f
--- /dev/null
+++ b/matlab/test/test_fiff_write_raw_buffer.m
@@ -0,0 +1,45 @@
+function test_suite=test_fiff_write_raw_buffer
+    try test_functions=localfunctions(); catch
+    end
+    initTestSuite;
+
+function test_fiff_readwrite_raw_()
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
+
+FIFF = fiff_define_constants;
+
+% read
+pathstr = fileparts(mfilename('fullpath'));
+fname   = fullfile(pathstr, 'data', 'test_raw.fif');
+info    = fiff_read_meas_info(fname);
+raw     = fiff_setup_read_raw(fname);
+[data, times] = fiff_read_raw_segment(raw);
+
+% write -> note that the original data was in 24 chunks of 600 samples, the
+% data is saved out as a single chunk of 14400 samples
+fnamenew = strrep(fname, 'test_', 'testout_');
+[outfid, cals] = fiff_start_writing_raw(fnamenew, info);
+fiff_write_int(outfid, FIFF.FIFF_FIRST_SAMPLE, raw.first_samp);
+fiff_write_int(outfid, FIFF.FIFF_DATA_SKIP, 0);
+fiff_write_raw_buffer(outfid, data, cals);
+fiff_finish_writing_raw(outfid);
+
+% read the new file
+rawnew     = fiff_setup_read_raw(fnamenew);
+[datanew, timesnew] = fiff_read_raw_segment(rawnew);
+
+% compare
+assertEqual(data,  datanew);
+assertEqual(times, timesnew);
+
+% clean up
+delete(fnamenew);
+