HP-71B OUT-register

[Klaus]

I want to use the unused bits of the HP-71B's OUT-register to control some devices (Like described in CHHU V2N7 page 25 "HP-71 controlled slide projector dissolve unit").
Does anyone know of a small LEX-File that permits manipulating the OUT-register?

Thanks for reading!
Klaus

[J-F Garnier]

I remember an implementation of a serial link with one OR line and one IR line. I think the LEX was called SERIOLX or SERIOLEX, the source was even published in one issue of a user journal (PPC or CHHU, or ...).

OR4 (in the card reader port) is a good candidate because it is not used for the keyboard, however, it is used for the module configuration daisy chain at each machine configuration.

I never attempted to play directly with the I/O lines of the Saturn, too risky for me! I prefer to use HPIL!

J-F

[Klaus]

Thank you form the answer.
The article you are referring to is almost certainly "50 cent serial I/O". I have come across it while reading old PPC issues.

I will have a closer look at it!

Kind regards, Klaus