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Difficulty with flashing an HP20b - Printable Version

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Difficulty with flashing an HP20b - jwhsu - 09-29-2015 01:09 AM

I've been reading this board with interest about converting an HP 20b into a WP 31S for my son and a HP 30b into a WP 34S for myself. I finally obtained an HP 20b and 30b for flashing. I do not have access to an HP cable and I don't have the time or the skill to make a custom connector, so I used a FTDI USB to TTL cable and followed the instructions both here and from this website on my HP 20b:

http://www.thereminworld.com/Forums/T/29229/diy-calculator-hp30b-to-wp34s

I was able to erase the calculator, however, when I try to flash the firmware with the WP 31S binary, I keep getting "cannot connect to WP34S". I am using the OS X flashing utility from the SourceForge site. I don't have access to windows to try to flash the calculator. I am hesitant to try to flash the 30b into a 34S as I am afraid I will end up with 2 bricked calculators in my possession. Is there any advise one can give to help with flashing these calculators. If not, is there someone out there who would be willing to help me with flashing the calculators (preferably in the US). Thanks for the assistance.

Jack


RE: Difficulty with flashing an HP20b - mivok - 09-30-2015 12:33 AM

I had the same issue (with a 30b) and a mac. I was never able to get flashing working with the mac utility.

My solution was to use MySamBa (windows version) with wine. If you have homebrew (http://brew.sh) you can do 'brew install wine'. You also have to link your serial port to ~/.wine/dosdevices/com1 using something like 'ln -s /dev/tty.usb..... ~/.wine/dosdevices/com1' so com1 maps to your actual serial port.

In addition, I found I had to really press hard with the pins (resistors in the instructions you linked to) to make a connection, or it wouldn't work at all. You can tell when you're pressing hard enough because both lights (send and receive) on the ftdi cable light up (assuming you have send/receive LEDs).


RE: Difficulty with flashing an HP20b - jwhsu - 10-04-2015 02:15 AM

(09-30-2015 12:33 AM)mivok Wrote:  I had the same issue (with a 30b) and a mac. I was never able to get flashing working with the mac utility.

My solution was to use MySamBa (windows version) with wine. If you have homebrew (http://brew.sh) you can do 'brew install wine'. You also have to link your serial port to ~/.wine/dosdevices/com1 using something like 'ln -s /dev/tty.usb..... ~/.wine/dosdevices/com1' so com1 maps to your actual serial port.

In addition, I found I had to really press hard with the pins (resistors in the instructions you linked to) to make a connection, or it wouldn't work at all. You can tell when you're pressing hard enough because both lights (send and receive) on the ftdi cable light up (assuming you have send/receive LEDs).

Thank you for the advice. Was able to get MySamBa working over Parallels (took a little while), but was able to successfully flash a 20b into a 31S for my son. Now to order some parts to convert the 30b into a 34S.


RE: Difficulty with flashing an HP20b - rprosperi - 10-05-2015 12:20 AM

(10-04-2015 02:15 AM)jwhsu Wrote:  Was able to get MySamBa working over Parallels (took a little while), but was able to successfully flash a 20b into a 31S for my son.

It would be a nice gesture if you document here how you got it to work with Parallels, so when the next Mac guy that comes here searching how to load a 31S/34S on a Mac, your notes will help him/her get it done.

Just like the earlier posts that helped you, yours will help the next guy. Which is why these Forums are so useful.


RE: Difficulty with flashing an HP20b - Geoff Quickfall - 10-05-2015 12:27 AM

good point Bob, it raises another: nothing like:

hpmuseum: xxxxx xxxxx

in google where xxxxx is a search keyword. Yes, google and the search function is your friend! Just like solder flux!

Geoff


RE: Difficulty with flashing an HP20b - jwhsu - 10-05-2015 02:48 AM

(10-05-2015 12:20 AM)rprosperi Wrote:  
(10-04-2015 02:15 AM)jwhsu Wrote:  Was able to get MySamBa working over Parallels (took a little while), but was able to successfully flash a 20b into a 31S for my son.

It would be a nice gesture if you document here how you got it to work with Parallels, so when the next Mac guy that comes here searching how to load a 31S/34S on a Mac, your notes will help him/her get it done.

Just like the earlier posts that helped you, yours will help the next guy. Which is why these Forums are so useful.

No problem. These were the steps I used to flash flash the 20b:
1) Install a copy of Win XP pro via parallels.
2) Update XP to SP3 (Google "download XP service pack").
3) Install FTDI virtual com port drivers
4) Plug in USB to TTY cable.
5) Ignore auto install. Go to device manager and manually install driver. Should now recognize cable at COM#.
6) Download MySamba and appropriate binary from WP 34S Sourceforge site.
7) Flash calculator as per the Theremin World site.
8) Start using the calculator.

The hard part was realizing that I needed to update XP before it would allow me to install the drivers. Before updating, I could not install the drivers, even when I forced the system to look at the directory where the drivers were installed. Hope this helps out others trying to flash a calculator on a Mac.

Jack


RE: Difficulty with flashing an HP20b - rprosperi - 10-05-2015 03:49 AM

(10-05-2015 02:48 AM)jwhsu Wrote:  No problem. These were the steps I used to flash flash the 20b:
1) Install a copy of Win XP pro via parallels.
2) Update XP to SP3 (Google "download XP service pack").
3) Install FTDI virtual com port drivers
4) Plug in USB to TTY cable.
5) Ignore auto install. Go to device manager and manually install driver. Should now recognize cable at COM#.
6) Download MySamba and appropriate binary from WP 34S Sourceforge site.
7) Flash calculator as per the Theremin World site.
8) Start using the calculator.

The hard part was realizing that I needed to update XP before it would allow me to install the drivers. Before updating, I could not install the drivers, even when I forced the system to look at the directory where the drivers were installed. Hope this helps out others trying to flash a calculator on a Mac.

Jack

Awesome! Thanks Jack!