V.92 code for external modems with Topic / IC Plus TP560x chipset

[Franc Zabkar]

I recently upgraded the code in a Lightspeed model 5600TP external
modem, with Topic / IC Plus TP560x chipset, from V.90 to V.92 using
the following ZIP:

http://www.lightspeed.com.tw/download/V92XPAustralia.ZIP

The readme file refers to a firmware image named "t1042ausv92.bin".
Unfortunately this file is not included in the ZIP. Instead there is
"t11102xnn.bin" which is preset for UK, and which also appears to
contain V92 code (there are references to V92 and V44). After
upgrading you may need to reconfigure your modem with Australian
parameters using the AT*NC40 command. Other country codes are also
selectable.

A scanned image (1.4MB) of the Lightspeed modem is available here:

http://members.dodo.net.au/~fzabkar/5600TP.jpg

Note that I have replaced the original non-flashable 2Mbit OTPROM
(AMIC, A278308A) with a 4Mbit 29F040 flash EEPROM. This gives me the
option of switching between the old and new firmware [by isolating pin
1, the topmost address bit, and wiring it high or low].

My V.90 connections with the new firmware appear to be solid (> 5KB+
downloads for incompressible files). However, I have not been able to
confirm the functionality of the V.92 code as my ISP appears not to be
V.92 ready.

The original V.90 firmware produced the following ATIn responses:

TP560 Data/Fax/Voice 56K Modem
External Controller Ver1.20, CheckSum=0EA2
TEST OK!
TP560 Data/Fax/Voice 56K Modem
DSP Ver1.10 CheckSum=89C6
Australia
0
Controller Ver1.20 Date:Nov 29 10:53
DSP Ver1.10 Date:Aug 29 16:24
Software Speakerphone
Program Memory CheckSum=9868

Immediately after the upgrade the new responses were:

TP560 Data/Fax/Voice 56K Modem
External Controller Ver3.00, CheckSum=B3B7
TEST OK!
TP560 Data/Fax/Voice 56K Modem
DSP Ver3.00 CheckSum=7620
UK <---- other country codes can be selected using AT*NCnn
0
Controller Ver3.00 Date:Nov 05 13:20 2001
DSP Ver3.00 Date:Nov 02 14:11 2001
Software Speakerphone
Program Memory CheckSum=29D7 <---- checksum of external firmware

I suspect that other external modems using the same TP560x chip may be
V.92 upgradable using the same .bin file. Note, however, that the
lightspeed modem uses a silicon DAA consisting of two ICs, Si3014-KS
and Si3021-KS. Hence I cannot be sure that modems using other DAA
types will be compatible with the aforementioned firmware.

-- Franc Zabkar

Please remove the 'g' from my address when replying by email.