My WP-34S : USB to Serial cable prototype

[jebem]

(01-23-2015 08:17 AM)MarkHaysHarris777 Wrote:  (1) I am interested if you could describe any troubles or frustrations you may have had soldering headers directly to the main board--- thanks for the pics by the way.

(2) Do you plan to flash with the batteries removed from the unit?

(3) Have you actually flashed yet, or still just in testing phase?

Hi Mark,

Welcome again to this nice MoHPC that I found just one year ago

You did mention Wang Computers. Did you work for WANG at some point?
I did, for about 20 years in Europe (Belgium and Portugal).
Wang PCS, Wang 2200 series, Wang OIS series, Wang VS series, you name it.

Looking back it is amazing how technology evolved this far and this fast!
It was only yesterday when a hard disk drive would store 10MByte (5MB internal and another 5MByte external mounting cartridges), where the disk heads flying over the pressurized disk surfaces did eventually "landed" over the disks, scratching them and destroying all the data!
I used to repair them, and at the end we had to do the alignment for compatibility reasons with other disk cartridges, using a alignment disk and a oscilloscope.


Concerning the WP-34S, I am a late adopter because I only discovered it after joining this forum.
So, others here are the real experts on the WP-34S, not me.

That said, electronics has been my second nature since tender age, despite it is more a hobby now, because I do not need these skills for my work.


To answer your questions:

1.
I never tried to solder pin headers to the PCB - I do not like to modify the original calculator structure. I'm a collector, you know...

And that is the reason why decided to build my own flash box.
I wanted a solution that allows me to flash any HP-20B or HP-30B as many times as I want. From scratch. And without any internal hardware changes.

However, I'm not that hand's skilled as many others here and elsewhere have reported repeatably:
"to flash the HP-30B, you just need an USB-to-Serial adapter. You do not need anything else..."

Well, I'm not able to flash the HP-30B by just using 3 bare wires from the USB-Serial adapter, touching the HP-30B's POGO back connector, while at the same time being able to use a clip to Reset the HP-30B, while pressing a key on the HP-30B, and then be able to press the Send on the PC program to upload the firmware...
This procedure would require me to have at least 3 hands
No offense to the other more skilled people here and elsewhere - I'm just having some fun here - no intention to start flame war at all. Apologies to anyone taking this statement as an offense


2.
I never use batteries inside my calculator when flashing.
That is why I have a dedicated 3.3V supply in my flash box cable.


3.
Yes, I use my flash cable as many times I need to.
Again, this method was shared to me/us by other more skilled people here in the MoHPC.
In fact, to flash a HP-20B or 30B, one just need a PC, a USB-to-TTL-Serial adapter and those 3 hands to handle the flash procedure

I have just built this flash cable to be able to use dedicated press buttons, like in the original HP flash cable. However, while the original HP flash cable was using PC serial interface, I'm using a PC USB interface as shared by other people here before me.

One final note, if I may:
The POGO connector is really tricky to build, and as i see it, it is the real challenge here.
One's need skilled hands and workmanship to succeed in building a functional POGO connector.
Obviously it is not my case, but I managed to build a working POGO connector afetr a few iterations and using different techniques.
Perfectible, yes, but I'm not looking for perfection. I'm happy with it as long as it fulfill my needs

If you decide to have a go and build your own flash box cable, please share it in this excellent MoHPC forum!

Cheers!
Jose