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+--- Forum: Not quite HP Calculators - but related (/forum-8.html)
+--- Thread: Flashing the WP34s (/thread-2475.html)
Flashing the WP34s - Elite - 11-22-2014 05:46 PM
Hello,
I would like to flash my 30b and have Harald's USB board.
After reading the documentation I want to ask the following:
-Why do I have to remove LB1 and LB2?
-Do you really need to connect both battery terminals?
-Wouldn't it be easier to just connect the board to the JTAG connector as there is GND, Rx0, Tx0, Vcc?
Elite
RE: Flashing the WP34s - BarryMead - 11-23-2014 04:50 PM
(11-22-2014 05:46 PM)Elite Wrote: -Why do I have to remove LB1 and LB2?
-Do you really need to connect both battery terminals?
-Wouldn't it be easier to just connect the board to the JTAG connector as there is GND, Rx0, Tx0, Vcc?
The LB1 and LB2 inductors are removed to allow the USB interface board to intelligently switch between
3.3V power from the FTDI chip and the 3V power supplied by the batteries. Not removing them would cause a conflict between these voltages. When the USB interface board supplies power there is NO-DRAIN on the batteries.
Yes you need to connect both battery terminals or you will only be powering your calculator off of one cell
when the USB cable is not attached.
You could attach the wires to the JTAG connector, but if you ever needed to repair the flash and the
JTAG connector is corrupted then others would not be able to help you with their JTAG equipment.
Hope this helps
RE: Flashing the WP34s - Marcus von Cube - 11-23-2014 06:35 PM
(11-23-2014 04:50 PM)BarryMead Wrote: You could attach the wires to the JTAG connector, but if you ever needed to repair the flash and theThe 6 pin connector visible from the back of the calculator is not JTAG, it's serial with some control pins (reset, erase, power). There is a JTAG connector inside the case but you need very special equipment to use it.
JTAG connector is corrupted then others would not be able to help you with their JTAG equipment.
Repairing the flash is totally possible with the USB board alone. You just need to perform a full erase to the flash with a piece of wire to activate the SAM-BA boot code.
RE: Flashing the WP34s - BarryMead - 11-23-2014 07:28 PM
(11-23-2014 06:35 PM)Marcus von Cube Wrote: Repairing the flash is totally possible with the USB board alone. You just need to perform a full erase to the flash with a piece of wire to activate the SAM-BA boot code.There have been some posts of people who corrupted the flash to the point that the normal samba boot code no-longer works. These people have had to resort to using the JTAG connector to program the flash.
I too had assumed that the poster was confusing the 6-pin serial programming header with the jtag connector but didnt' want to mention it. He could wire his USB board to the 6-pin serial programming header if he wants, but that would just make the wires longer.
RE: Flashing the WP34s - Elite - 11-23-2014 09:09 PM
(11-23-2014 07:28 PM)BarryMead Wrote: I too had assumed that the poster was confusing the 6-pin serial programming header with the jtag connector but didnt' want to mention it. He could wire his USB board to the 6-pin serial programming header if he wants, but that would just make the wires longer.
Actually you have assumed correctly. I was thinking until now that the serial port is the JTAG.
I now have to ask: Where is the JTAG connector?
While looking through older posts I found this one:
http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv020.cgi?read=186826
Here Macus describes making a serial cable for the WP34s.
I noticed that the wire to JP5 is soldered on the right hand side in comparison to Harald's board (left hand side).
Compare: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=223186
That shouldn't make a difference? Also I think that this method easier because you don't have scrape off as much plastic as when installing the USB board.
Let's assume that I connect the serial board to the six pin serial port, I would still have to remove LB1/2 and connect the battery terminals? In case I decide to remove the board e.g. to transplant it to another WP34s would that first calculator continue working with batteries only?
I do have another question regarding the crystal:
Here: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv020.cgi?read=209206
it says that one should press On + C + C after every update in order to tell the system that you have a quartz installed. I am a bit confused? Could someone ellaborate?
Elite
RE: Flashing the WP34s - Marcus von Cube - 11-23-2014 11:05 PM
I've no experience with Harald's board. The LB1/2 thing seems to be releated to USB power, not the serial signals.
The jumpers are jumpers. It doesn't matter which side you connect to.
ON+C-C is a keyboard sequence in the standard calc.bin (or calc_full.bin) image to make the crystal the main oscillator. If this works after the modification it is better to use one of the _xtal or _ir images which do not need the keyboard sequence. They start the crystal oscillator on boot up.
RE: Flashing the WP34s - BarryMead - 11-23-2014 11:58 PM
(11-23-2014 09:09 PM)Elite Wrote: I now have to ask: Where is the JTAG connector?
While looking through older posts I found this one:
http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv020.cgi?read=186826
Here Macus describes making a serial cable for the WP34s.
I noticed that the wire to JP5 is soldered on the right hand side in comparison to Harald's board (left hand side).
Compare: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=223186
That shouldn't make a difference? Also I think that this method easier because you don't have scrape off as much plastic as when installing the USB board.
Let's assume that I connect the serial board to the six pin serial port, I would still have to remove LB1/2 and connect the battery terminals? In case I decide to remove the board e.g. to transplant it to another WP34s would that first calculator continue working with batteries only?
The JTAG connector is that 8-pin connector near the top of the calculator.
If you install Harold's board on a calculator I don't think you will ever be removing it. If you do, you would
have to re-connect the LB1 and LB2 points with wire or you will not get battery voltage to the calculator.
Installing Harald's board is very precise. It is designed to fit over the case attachment post once you
trim down the reenforcement tabs. When you do it this way it lines up perfectly. The older photo you
referenced was for attaching a 2.5mm phone jack to the serial ports of the calculator. I also built a
calculator with this configuration. Then you need a special FTDI cable and a 3.5mm to 2.5mm adapter.
The cable for this phone jack arrangement is and FTDI TTL232R_3V3_AJ cable.