D-Sample was TI's flagship GSM MS development board in its day, originally created some time in 2002 and apparently used for a few years afterward. In 2015 I (Mother Mychaela) was able to snag an early D-Sample kit — see pictures. The board I got features Calypso chip version F741979BGHH (Calypso C05 rev B) and came with a firmware image in its flash dated 2002-09-17 — but in later years TI must have populated newer Calypso chip versions, up to the final Calypso C035 with DSP ROM 3606, onto the same PCB footprint. TI's TCS211 firmware from 2007 still supported D-Sample as one of its two official platforms (along with Leonardo), expecting that latest version of Calypso chip on the board.
D-Sample development platform is very remarkable in its physical construction: there is the main board that holds the GSM MS core and can function by itself, and then there is the optional handset piece containing the LCD, keypad buttons and audio transducers. The handset piece needs to be present and connected in order to hear downlink audio and supply uplink speech during voice calls, even if AT command control is used, and it is also needed in order to run UI-enabled firmware that uses the LCD and the keypad. However, if one runs non-UI firmware (AT commands only) and wishes to exercise non-voice GSM functions as in CSD, SMS, USSD and GPRS, only the main board is needed.
Another remarkable feature of TI's D-Sample platform is their choice
of LCD: 176x220 pixels, 16-bit color.
It is one of industry standard LCD sizes, not a super-exotic custom size,
but what is remarkable is the use of this huge screen size back in 2002
on a platform that was generally thought of
as low-end
.
We are not aware of any commercial, mass-produced phone
with TI Calypso chipset that features this big of an LCD!
There are known high-end
Calypso phones (featuring a camera,
WAP and MMS functionality in the firmware) with 128x128 pixel displays;
it is plausible that someone may have built one with a 128x160 pixel LCD,
but 176x220 is highly unlikely for the first half of 2000s decade.
Furthermore, TI's own previous platforms (C-Sample and earlier)
featured 84x48 pixel black&white LCDs; the jump from 84x48 pixel B&W
to 176x220 pixel full color, with nothing in between, is truly
remarkable.
TI's choice of 176x220 pixel display size on D-Sample has a huge bearing on our own FreeCalypso project. The demo, prototype or PoC (proof of concept) handset UI code in TI's TCS211 reference firmware supports only C-Sample and D-Sample display sizes, i.e., two extremes with nothing in between; furthermore, the old C-Sample UI code is strictly B&W (naturally so, given the actual C-Sample LCD) and even more broken than the D-Sample version due to bitrot: in the time period from which our available sources date, only the large screen version was maintained. Therefore, we seek to recreate this 176x220 pixel display size on our own FreeCalypso devboards, taking advantage of the fact that it is an industry standard LCD size with new modules available.
Despite having a real, TI-made D-Sample board in our FreeCalypso HQ lab,
we aren't able to do much with it.
Because none of our TI firmware sources or semi-sources include their
tpudrv10 module (i.e., we have neither tpudrv10.c
nor tpudrv10.obj), we are unable to run our own FreeCalypso
firmware on this D-Sample board with working GSM: we made an attempt
to reconstruct tpudrv10 code from disassembly of the
original 2002-09-17 firmware image, but it still doesn't work.
The only way how we are able to operate our D-Sample board as a GSM MS is by running the original 2002-09-17 firmware image it came flashed with. This image (and hence the manufacture date of our board) appears to predate TI's development of the 176x220 pixel UI which we are familiar with through 2007-era TCS211 code base, hence it requires control via AT commands while the LCD stays dark. However, using this ancient fw image and operating it via AT commands, we are able to bring up the MS successfully, register to a GSM network and exercise calls; both voice and CSD calls work well. Because Calypso chip version is F741979B, i.e., non-AMR-capable Calypso C05 rev B, voice calls support only FR, HR and EFR codecs, not AMR.