HP97 'with RS232 connector'

[Mark Hardman]

To quote Katie's article "Enhance your HP-97 -- Add a Clock and More":

The HP-97 and HP-97S are identical except for the addition of the I/O pod on the 97S. This project demonstrates how it is possible to achieve some of the functionality of the 97S (including the pod) on a plain HP-97. In particular, it demonstrates how input can be feed to a 97 in the same way that the 97S pod does, only more so....