From: Glen Larsen Subject: HOME-BREW: Powerglove Menelli box (serial interface) Date: Wed, 10 Sep 1997 15:01:33 -0400 Message-ID: <9709101501.ZM7951@glacier.pitts.miles.com> Hello, If you are not familiar with the PC interface for the Mattel powerglove, please feel free to delete this message. I posted this to HOMEBREW-VR and didn't get a response so I'm hoping someone here has built the Powerglove Menelli box (serial interface). I'm trying to find someone who can answer a few specific questions. I am interested in using the powerglove and Menelli box with LINUX. My work so far is based on the web page on the Menelli box (http://www.cms.dmu.ac.uk/People/cph/menelli.html) but I notice some differences between the circuit diagram and the PCB layout and I'm wondering which is correct. I would like to verify with someone if they used these PCB layouts successfully as is, or if they need to be slightly modified. Sorry if these questions are pretty technical, I'm just trying to make sure I know what I'm building. 1. How does the MAX232 chip get +5V? The circuit diagram +5V goes in to pin 16 but I can't trace any path on the PCB layout between pin 16 and the voltage source. 2. How does C7 (0.1 uF) get +5V? The circuit diagram again indicates a direct connection but on the PCB, C7 goes to pin 23 and 25 on one side and to pin 22 on the other side (rather than to +5V at pin 48). 3. How is R19 grounded? The circuit diagram shows a ground (after coming through... a switch?) to pin 24. The PCB has a connection between pin 24 and R19 but no connection to ground at the same point. 4. What resistor is attached to pin 26 of the 68HC811? The circuit diagram shows a resistor which doesn't exist on the PCB layout. There are 21 resistors on the PCB and parts list, but 22 on the circuit diagram. Should I ignore the extra one the circuit diagram at pin 26? 5. What size capacitors are C3 and C6? The circuit diagram says 4.7uF but the parts list says 470F. I assume the parts list is a typo (470F would be desk sized!) but I want to make sure its not 470pF or something. 6. What is an equivalent for the HC33/U 8MHz crystal? I have found the U49-20-80 available from Newark, but I don't know if it is a direct replacement. An engineer at US Crystal said I may need to change the 18pF capacitors to 36 pF for the new crystal. Is this true? If the PCB layout have been used successfully as is, I can just build the interface as is. But I'd sure like to understand the difference between the PCB and the circuit diagram. Thanks in advance for your help or directions to another source. Glen Glen Larsen gcl@design.pitts.miles.com phone: 412-777-2929