There is a bank of twelve buttons which access the "FX Modules" in the TSR-24S. Whether you're creating new programs or editing existing ones, the FX Modules and their respective buttons will get a lot of use. There are ten categories of effects modules with a button for each: Reverb, Delay, Chorus, Pitch, Sampler, EQ, Flange, Modulation, Mixers, and a category called More. The other two buttons in this group, the < and > buttons, are used to move to the first parameter of each effect in the selected algorithm.

The LCD display is a 2-line by 16-character display. Many screens offer menu choices that are selected by pressing any one of four "Access" buttons to the right of the display. These Access buttons act much like "function" keys on a computer; their function varies from screen to screen. Furthermore, the Access buttons are user programmable. For example, let's say one of your favorite programs is a delay program with reverb, and you constantly need to adjust the delay time for whatever reason. Rather than press the Delay FX Module button then scroll to the delay time parameter, one of the Access buttons can be programmed so that one press of the Access button takes you immediately to the desired parameter. And programming the Access buttons is a piece of cake. Locate the parameter you want to assign an Access button to, then press the Access button (any one of the four) for two seconds. That's it. Store the edited program, and next time the program is recalled, pressing that Access button instantly takes you to the parameter assigned to it.

To the right of these Access buttons are four "Program" buttons. They are +, -, Compare, and Store. The + and - buttons are used to step through the programs in memory. If you're editing a program in any way, the Compare button lets you compare the edited program with the original. The Store button saves your edited work to memory. To the right of these buttons are four "Parameter" buttons labeled +, -, Previous, and Next. The Previous and Next buttons scroll through the parameters in the program. The + and - buttons are used to alter the selected parameter's value. If you're in a delay program and want to shorten the delay time, simply press the Delay FX Module button and the LCD display switches to the first parameter screen for the delay. Press the Parameter Next button to locate the delay time parameter, then use the + and - buttons to alter the delay time. If you change a parameter and want to store that setting with the program, simply press the Store button.

There is another bank of six buttons called the "Edit" buttons. These are only used to edit existing algorithms or to create new ones. More on these later. Finally, there are four more buttons used to access the TSR-24S's MIDI capabilities, program and algorithm naming function, various utilities such as display contrast setting and factory program initialization, and the fourth is the effects Bypass button.

To the right of the LCD display is a large red LED display that shows the current program number, and you get a couple of LED input level meters, one for each channel. There are several small LEDs that indicate current operating status. The Store LED lights to show that changes have been made to the current program; the program must be stored to memory if the changes are to be kept. The Bypass LED lights to show that all effects have been bypassed. The Overload LED indicates digital information overflow in the microprocessor and is a warning that levels should be adjusted to avoid distortion. The Mono LED lights to show that the currently selected program is configured to be used with a mono input. The MIDI LED lights to indicate MIDI information is being sent or received. The Edit LED lights when the unit is in the Edit mode (as opposed to the Performance mode). The Edit mode is where algorithms are edited or created. Finally, the Link LED lights when in the Algorithm Link mode.

The basic building blocks of the algorithms and programs in the TSR-24S are the effects modules. A single one of these modules can be used as an algorithm by itself, or any combination of these modules can be "linked" together. How many modules you link together is only limited by the amount of "algorithm memory" available. This memory is different than the "user" memory used for storing programs, and different modules will use up different amounts of algorithm memory.