It turns out that it was not very difficult to expand the program to solve a seventh order set of linear equations. The changes required are:

1. Insert a CLSum command immediately after the CLVARS near the beginning of the program.

2. Add the following subroutine at the end of the program:

T0001 LBL T

T0002 STO i

T0003 x<>y

T0004 25

T0005 x>y?

T0006 RTN

T0007 3

T0008 STO+ i

T0009 RTN

3. Replace the STO i command with a XEQ T command at the following program locations:

B0003

B0009

C0006

D0006

D0014

E0006

F0005

F0012

F0020

G0003

G0007

G0011

The operating instructions are not changed.

For the test problem with a seventh order sub-Hilbert as the matrix A and all ones as the vector B the results are

Exact hp 33s Relative Error
56 56.068858872 1.229E-03

-1512 -1513.60579469 1.062E-03

12600 12611.7867396 0.935E-03

-46200 -46238.6331388 0.836E-03

83160 83222.8860386 0.756E-03

-72072 -72121.7495754 0.690E-03

24024 24039.2548347 0.634E-03

for a mean relative error of 0.878E-03. For the same problem the HP-41 MathPac yields a mean relative error of 0.837E-02 and the ML-02 program for the TI-59 yields a mean relative error of 1.033E-04. In a subsequent submission I will provide comparisons with other machines and with other problems.