Re: Non-working Wand Message #11 Posted by Vassilis Prevelakis on 29 Jan 2005, 4:30 p.m., in response to message #5 by Tony Duell
Tony Duell on 29 Jan 2005, 2:35 p.m., wrote
> ... the module can be used with a little add-on circuit to
> download programs into the 41 (without needing an HPIL interface).
Yes! I remember in the early 80s I dissasembled the HP-41 interface of my second wand (won as a reward for contributing programs to the European Program Library -- UPLE), and connected it to the user port of my BBC micro.
Later I found out that I could enter programs by touching the tip of my other (intact) Wand to the CAPS LOCK LED on the BBC keyboard and then pulsing the LED under program control.
Almost 20 years later I found out that I could have burned the sensor on the Wand if the external LED was too bright. Ignorance is bliss :-)
**vp
PS I also connected the Wand (sans HP-41 interface) to the joystick port of my BBC to read barcodes distributed by a UK magazine called (I think) BBC Micro User.
The wand interface is just three wires, +5V, GND and TTL output.
|