In a thread starting on of November 2, 2007 Stefan Vorkoetter announced that a Matrix Multi-Tool program for the HP-35s was available at his site http://www.stefanv.com/calculators/hp35s_matrix_multitool.html . He noted that his program "... is a long way from being as powerful as the facilities provided by the 15C, 41C/Advantage, or 42s, but it does provide several useful matrix operations in one simple tool. It is loosely modelled after the Advantage Pac matrix *program* and provides an easy-to-use subset of the functionality of the matrix *library.*..."

The program described in detail in Article 886 was written to work with Stefan's program and provide more of the matrix processing functions that one finds in machines such as the HP-28S and TI-86. This program relies on Stefan's program for entry and readout of data, and for solution of linear equations. Stefan's program uses one matrix (Matrix A) and one vector (Vector B) for input and output. His program also uses a second matrix (which I shall call Matrix C) during the linear equation solution. Matrix C is not directly accessible through Stefan's input and output routines. This program adds a storage matrix (which I shall call Matrix D). Additional matrix processing functions provided by this program include:

Calculation of Frobenius norm (ABS), the row norm, and the column norm of Matrix A.

Moving of matrices between Stefan's matrix A and either his matrix C or the added storage matrix D using store, recall and exchange commands. Moving of matrices directly between Matrix C and Matrix D is not provided.

Matrix mathematics including the product of Matrix A and Vector b, the product of Matrix A and Matrix C, and the sum or difference between Matrix A and Matrix C.

Special operations such as the dot product of Matrix A and Matrix C, the formation of an identity matrix in Matrix A, the filling Matrix A with a user-defind constant value, and the transpose of Matrix A.