28 Apr
2019
28 Apr
'19
12:28 a.m.
Following up on this inquiry, the datasheet in question has been
located - one of the long-timers here sent me a copy. It has now been
added to the archival collection:
ftp://ftp.freecalypso.org/pub/GSM/Silabs/
I am now waiting for one of those Mot W220 phones I ordered on ebay to
actually arrive. I ordered the first one back on April 1 from a
seller in Albania, and it appears to have fallen into a black hole
somewhere: the seller marked it as shipped, but there is no tracking
number, and it has been almost a month. (The "estimated delivery"
says April 16 to May 2, thus another week before I can report it to
ebay as not delivered.) Giving up on that one, I ordered two more
yesterday, one from Serbia and one from Canada - hopefully at least
one of them will arrive.. And I did find the schematics for this
phone, yay - if anyone needs them, I can add them to the FTP site.
The notes in the OBB wiki say that Mot W220 has the Calypso boot ROM
enabled and that it is accessible via the headset jack with the same
cable as on Compal-made C1xx models, and the schematics seem to concur,
so I am hopeful... But here is a mystery: there is another very
seemingly-similar phone called C168, it is from the same time period
and has essentially the same components, and it is mentioned on the
same Potential Calypso Targets page as the W220, although it just
lists the use of the Si4210 transceiver but says nothing about code
download access. I already have one of those C168 phones - it was
much easier to get than W220 because there are plenty of USA sellers
for this model (AT&T carried them as basic prepaid phones just like
the C139) - but I had zero luck in getting bootloader access through
the headset jack on this phone. Unlike with the W220, I also had no
luck in finding any downloadable schematics for the C168, so I don't
know if this model has the boot ROM disabled via nIBOOT unlike the
W220, or if the headset jack does not function in UART mode until the
firmware configures it for the AT command interface after boot, or
what.
Has anyone else tried gaining code download access on the C168? Was
your experience the same as mine? Has anyone figured out where the
blockage is?
Frustrated,
Mother Mychaela with her curious-as-a-cat tinkerer hat on