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Re: Just how rare are 8701 chips these days ?

Posted: Sat Sep 09, 2017 1:05 pm
by eslapion
ViperSan wrote: Fri Sep 08, 2017 2:53 pm...
The keyboard works and has been cleaned but some keys need some serious pressure to get a response.
The rubber ..carbon impregnated stubs need restoring..
..anyone found a suitable paint on permanent liquid to do this job ?
Chemtronics CW2605

It's expensive but I can do 2 complete keyboards with it. Unlike other contacts renewers, it is not based on cyanoacrylate so it will not crack and flake off over time.

I renewed my PET style keyboard back in late 2006 with this and it still works like new.

Re: Just how rare are 8701 chips these days ?

Posted: Sat Sep 09, 2017 4:02 pm
by ViperSan
eslapion wrote: Sat Sep 09, 2017 1:05 pm
ViperSan wrote: Fri Sep 08, 2017 2:53 pm...
The keyboard works and has been cleaned but some keys need some serious pressure to get a response.
The rubber ..carbon impregnated stubs need restoring..
..anyone found a suitable paint on permanent liquid to do this job ?
Chemtronics CW2605

It's expensive but I can do 2 complete keyboards with it. Unlike other contacts renewers, it is not based on cyanoacrylate so it will not crack and flake off over time.

I renewed my PET style keyboard back in late 2006 with this and it still works like new.
Thanks buddy ..
Just checked and is available from CPC or RS components in the UK ..
As you say ..
not cheap ..but if it is permanent ..then worth the cost.

Also ..searched on ebay for Chemtronics CW2605
..and this product came up in the search ..
Maybe is the same stuff ..but 30% cheaper ?
http://www.ebay.co.uk/itm/ChemWik-Rubbe ... OSwPWRZRIi~
rgds
VS

Re: Just how rare are 8701 chips these days ?

Posted: Sat Sep 09, 2017 4:54 pm
by eslapion
ViperSan wrote: Sat Sep 09, 2017 4:02 pmAlso ..searched on ebay for Chemtronics CW2605
..and this product came up in the search ..
Maybe is the same stuff ..but 30% cheaper ?
http://www.ebay.co.uk/itm/ChemWik-Rubbe ... OSwPWRZRIi~
The MPN is CH-CW2605 so this seems to be the same but there is a caveat. This product really has a shelf life of about 18 months.

Maybe you'll get an expired item if you take the one on eBay.

Re: Just how rare are 8701 chips these days ?

Posted: Sat Sep 09, 2017 4:58 pm
by ViperSan
...noted..
thanks

Re: Just how rare are 8701 chips these days ?

Posted: Sun Sep 10, 2017 2:22 pm
by ViperSan
Got some CH-CW2605 on order ..but am convinced the other Plus 4 issues are related to that crappy ribbon and connectors to the keyboard..
So for a few £s more ..
I ordered some ready made 20 pin female to female arduino (wire) 20cm ribbons ..and 2.5mm pitch right angled single pin headers ..
I'm sure I can do a better job than the original commodore push fit connectors and non flexible ribbons..
I'll let you know..
rgds
VS

Re: Just how rare are 8701 chips these days ?

Posted: Mon Sep 11, 2017 1:30 am
by eslapion
ViperSan wrote: Sun Sep 10, 2017 2:22 pm Got some CH-CW2605 on order ..but am convinced the other Plus 4 issues are related to that crappy ribbon and connectors to the keyboard..
So for a few £s more ..
I ordered some ready made 20 pin female to female arduino (wire) 20cm ribbons ..and 2.5mm pitch right angled single pin headers ..
I'm sure I can do a better job than the original commodore push fit connectors and non flexible ribbons..
I'll let you know..
rgds
VS
Please post a few pics and start a new thread about this.

Re: Just how rare are 8701 chips these days ?

Posted: Tue Sep 12, 2017 6:44 pm
by ViperSan
So got the C16 pcb working ..
now fully populated chip wise ..which leaves the modulator issue.
I'm using one borrowed from a Plus4 ....which is exactly the same unit.
I could probably bypass this a few descrete components ..but the C16 will not produce composite without it ..
the chroma and luma are combined within the RF modulator itself..
Does anyone have an RF modulator from either a scrap Plus4 or C16 they can sell me ?
seems a pity not to have it complete..
rgds
VS
Image

Image

Re: Just how rare are 8701 chips these days ?

Posted: Wed Sep 13, 2017 4:34 am
by eslapion
ViperSan wrote: Tue Sep 12, 2017 6:44 pm now fully populated chip wise ..which leaves the modulator issue.
I'm using one borrowed from a Plus4 ....which is exactly the same unit.
I could probably bypass this a few descrete components ..but the C16 will not produce composite without it ..
the chroma and luma are combined within the RF modulator itself..
Does anyone have an RF modulator from either a scrap Plus4 or C16 they can sell me ?
...
Instead of a modulator, may I suggest... https://www.digikey.ca/product-detail/e ... ND/4744313

Nonetheless, this should in a thread of it's own. It has nothing to do with the rarity of the 8701.

Re: Just how rare are 8701 chips these days ?

Posted: Wed Sep 13, 2017 10:51 am
by ViperSan
Agreed .
In future I will start seperate threads.
Certainly I shall do this for the plus4 keyboard ribbon mod.
thanks for the suggestion.
rgds
VS

Re: Just how rare are 8701 chips these days ?

Posted: Wed Sep 13, 2017 1:48 pm
by ViperSan
Just ordered a pack of 5 x FMS6410 from RS components for 50p each including delivery ..
I suspect Digikey and Little Diode are exploiting folk with their prices..
rgds