[Yaesu] FT-ONE - memory board. Anyone got one, made one, or want one?

[Dr. Gerald N. Johnson]

That is a WEIRD ram chip using 4 and 2 bit addressing shared with data 
storage lines. It can be best emulated with a PIC chip to handle the 
sequencing and having adequate internal memory.

I saw one advertisement for the FT-ONE that included memory backup as a 
free option.

Since 512 bits seems small for storing 20 frequencies, might it be that 
there is some memory already and this is just an expansion board since 
you have the battery back up provisions?

So you have 128 4 bit words. 1 word for band, 3 words for kHz, so a 
minimum of 4 words per frequency. IIn 128 words there are 32 
frequencies. Or taking 4 words for the kHz to 100 Hz, 5 words per 
frequency saved in BCD, 128 words has room for 24 frequencies. And using 
3 bits for band, and storing the kHz in straight binary rather than BCD, 
there's room for even more.

You'll need to read Japanese or find a data sheet in English to ever be 
able to replicate the timing and the function with a PIC microprocessor.

The FT-ONE was reviewed in QST in August 1983. I didn't think it was 
that new. The reviewer noticed reciprocal mixing in casual operation 
meaning the phase noise of the synthesizer is really bad and unsuited 
for 40 meters in Europe.

I didn't find a catalog from 1983 with Panasonic components in a quick 
search so I quit looking.

73, Jerry, K0CQ

On 6/3/2011 12:48 PM, Dr. David Kirkby wrote:
> On 06/ 3/11 06:06 PM, Dr. Gerald N. Johnson wrote:
>> I'm too lazy to download the FT-ONE manual to answer my next question.
>> So I'll post it here, what memory chips were used and exactly which year
>> was the FT-ONE introduced? I have catalogs back before ICs so I can look
>> for prices. One could look in ham store catalogs or magazine
>> advertisements to see the factory offered options and prices.
>>
>> Then an important question is how many were sold without the added
>> memory and how many are still in use?
>>
>> It may prove way more profitable to do a whole sale replacement of all
>> the miniature aluminum electrolytics that are partly failed having dried
>> out, leaked liquid electrolytics eating traces, and having high ESR. Few
>> are bad enough to make easy circuit tracing but replacing the entire
>> batch should make the radio work much better.
>>
>> 73, Jerry, K0CQ
>
> The rig came out in 1982 I think.
>
> The chips used on the optional memory board are MN1203, which are 256
> bit (64 words by 4 bits) static RAM. Two of them were used for a total
> of 512 bits.
>
> I must admit, given there are 10 memories for VFO A and 10 for VFO B, I
> can't for the life of me work out how all that data can be kept with
> only 512 bits.
>
> There's a data sheet on the chip here:
>
> http://pdf1.alldatasheet.com/datasheet-pdf/view/158280/PANASONIC/MN1203.html
>
>
> and the FT-ONE techincal manual has the details on page 3-42 - page 93
> of the PDF at
>
> http://www.g8wrb.org/data/Yaesu/FT-ONE/Yaesu_FT-ONE_technical_manual.pdf
>
> I've not looked in any detail, but it might be possible to replace the
> two MN1203s by a single modern device. That would make the board layout
> quite easy. If not, and two modern devices have to be used, one would
> probably need surface mount to fit them in. I guess for a one-off,
> getting a couple of the original chips would not be impossible, but it
> might be less hassle to use modern chips, even though one would not use
> 99% of their capacity.
>
> Apart from the two chips, there's a couple of connectors which make
> electrical contact and support the board. There's also a few R's and
> C's, but nothing much.
>
> As to how many were sold with the board, and how many remain in use I
> don't know. I know I have an FT-ONE which does NOT have the board, but
> that's just a sample of 1.
>
>
> Dave, G8WRB
>