diff --git a/doc/1-intro/glossary.md b/doc/1-intro/glossary.md
index d76473ae6..5c0d07e89 100644
--- a/doc/1-intro/glossary.md
+++ b/doc/1-intro/glossary.md
@@ -12,6 +12,8 @@
 
 **asset**: an instrument, wavetable or sample.
 
+**bit**: a single binary on-off value.
+
 **bitbang**: to achieve PCM sound by sending a rapid stream of volume commands to a non-PCM channel.
 
 **bitmask**: a set of bits which represent individual single-bit toggles or groups representing small numbers. these are explained fully in the [hexadecimal primer](hex.md).
@@ -72,7 +74,7 @@
 
 **LFO**: low frequency oscillator. a wave with a slow period (often below hearing range) used to alter other sounds.
 
-**LFSR**: linear-feedback shift register. an algorithm of generating pseudo-random noise that loops, also known as "periodic noise". depending on the location of the two "taps" used, different lengths of noise loops are generated.
+**LFSR**: linear-feedback shift register. a method to generate pseudo-random noise that loops, also known as "periodic noise". within a sequence of on-off bits, it does math to combine the bits at specified locations called "taps", then shifts the whole sequence and adds the resulting bit on the end, guaranteeing a different state for the next pass. depending on the locations of the taps, different lengths of noise loops are generated; for short loops, this will affect their tone.
 
 **macro**: a sequence of values automatically applied while a note plays.
 
@@ -130,6 +132,8 @@
 
 **supersaw**: a sound made up of multiple saw waves at slightly different frequencies to achieve a chorusing effect.
 
+**tap**: a specified bit location within an LFSR.
+
 **tick rate**: the number of times per second that the sound engine moves forward. all notes and effects are quantized to this rate.
 - this usually corresponds to the frame rate the system uses for video, approximately 60 for NTSC and 50 for PAL.
 
diff --git a/doc/7-systems/tia.md b/doc/7-systems/tia.md
index 1de97ffa8..d38ccf0a9 100644
--- a/doc/7-systems/tia.md
+++ b/doc/7-systems/tia.md
@@ -31,13 +31,24 @@ Furnace isn't complete without this one...
 
 a song can be exported to assembly code for use with the TIunA software driver for the Atari 2600. see [TIunA on GitHub](https://github.com/AYCEdemo/twin-tiuna) for explanations of the export options.
 
+## chip config
+
+the following options are available in the Chip Manager window:
+
+- **Software pitch driver**: use TIunA, a software pitch driver similar to TIATune. it increases pitch precision by rapidly switching between two pitches.
+- **Old pitch table**: use an older method to calculate pitch. only for compatibility.
+- **Mixing mode**: changes mixing mode.
+  - **Mono**: normal output.
+  - **Mono (no distortion)**: process each channel separately to eliminate distortion.
+  - **Stereo**: output two channels on left and right.
+- **PAL**: run slower blah blah blah
+
 ## info
 
 this chip uses the [TIA](../4-instrument/tia.md) instrument editor.
 
 the arp macro's fixed mode operates differently, writing the direct pitch to the chip. here's a list of pitches.
 
-
 ### shape 1
 
 | pitch |    NTSC | note | cent |    PAL  | note | cent