CR702 radio diode BIT order

[bluebrickrick]

nd Healthy & happy New Year.

Sorry, also posted on a radio sticky elsewhere

My Radio has died so I unearthed another CR702 from the archives, from a donor unknown AND SO the ugly code reared it's even uglier head !

Label is faded so can't establish the serial number and ask by normal means but after searching the diode setting of the code on this model was found, have opened and recorded the diode absent slots which are D7, D9, D10 & D12.
Being vaguely conversant with BCD coding I tried the obvious without success, further searching found a bit decode (I think from a CR708) which resulted in a code of 2513, no go again.
Further searching tonight gave an Australian Geocities site of OZBRICK850, which appears to have been kidnapped by Aliens and near the start of this thread a couple of ZIP files for decoders, which seem to have become unzipped and evaporated.
PLEASE can someone point me at somewhere that gives the bit order for the 702 before keyboard Covid gets me ?? TIA Rick in freezing Broadland

[360beast]

If you don't get any information on how to decode the 702 then I've got a CR-906 with no code available.

[Piet22]

Strange. 2513 should work



You could try 4313 for the CR705

.

[360beast]

Originally Posted by Piet22

Strange. 2513 should work



You could try 4313 for the CR705

.

What programme is that to find the codes?

If I gave you the serial number of the CR-906 I have would you be able to get the code please?

[bluebrickrick]

Thanks for that Piet22, much appreciated I will try both combinations just in case I input the 1st one incorrectly yesterday. 1111 & 6666 did not work.

I too am interested in what the software is as the programs referred to here as downloadable were not available when I tried, but it was ten year old + message

[bluebrickrick]

Bingo! and many thanks

Retrying 2513 gave the same Err result but 4313 worked fine, despite the fact that it is a CR702 and not a 705 ??

Have been tying the remains of the brain in knots trying to work out the bit order, given the 4 x 0 slots which are required for the other digits, the 1 has to be a 7 (1 1 1), 2 unjumbled combo of D1-3 and D4-6 give that, then it turns to worms,
I'll read the diodes on the unit still in the car which I know the code for, might show the pattern which would be handy for anyone in the future without software or someone's good nature to fall back on - all very Bletchley Park here but others may well tread the same path.
Thanks again for unlocking it for me, I'm Luddite enough to still enjoy a cassette while driving

[Piet22]

Originally Posted by 360beast

What programme is that to find the codes?

If I gave you the serial number of the CR-906 I have would you be able to get the code please?

It is not possible to calculate the code from the serial number.
Volvo has a database that allows them to find the code based on the serial number.

Piet

[Piet22]

Originally Posted by bluebrickrick

Bingo! and many thanks

Retrying 2513 gave the same Err result but 4313 worked fine, despite the fact that it is a CR702 and not a 705 ??

It is even more complicated.
The code calculator program I used this morning has two settings: a common variant and a CR705 variant.
I have another code calculator program that does the same but uses two separate programs. One is called CR-905 calculator and the other is called CR-705 calculator.
The results of the common variant (top left) are always the same as the results of the CR905 calculator (top right)
However, the results of the CR705 variant (bottom left) are not always the same as the results of the CR705 calculator (bottom right) So one of the two probably has a programming error.
Unfortunately, with your diode configuration both programs give the same results so that does not help me to find out which of the two programs cannot be trusted. I suspect the bottom right version sometimes displays a 6 when it should be a 1 but I'm not sure.









If you send me a pm with your email address I'll mail you the programs. Bitdefender has declared them all virus-free.

[Piet22]

Something else that might be of interest is that it is possible to obtain the code from the CT-503, CT-505, SC-700, SC-802 and SC-805 (and American equivalents). These radios were made by Mitsubishi and have the code stored in a small (27C01) eprom on the mainboard.
To radio has to be completely disassembled to fit a connecting-clip on the eprom. However, the good news is that the eprom can be read as mounted on the PCB-board; there is no need to desolder it.



The digits of the code are in position 00, 04, 08 and 0C.
The code for this radio is 5-5-2-6



The SC-800 and SC-801 manufactured by Alpine also store the code in a 27C01 eprom but this info is coded.

[bluebrickrick]

'New' radio installed and both radio and cassette working nicely.

I only realised after cleaning the bezel that the one coming out was actually a CR708 so direct comparison with the CR702 may not be possible as it has a different PCB

However in case it helps someone else on the same quest, here are the diodes installed (1) or not (0), its code is 5332

D
1 0
2 0
3 1
4 1
5 1
6 0
7 1
8 1
9 0
10 1
11 0
12 1
Thanks VOC Forum members for another win