Just how rare are 8701 chips these days ?

Disk drives, Monitors, SuperCPU etc.
ViperSan
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Just how rare are 8701 chips these days ?

Post by ViperSan » Mon Sep 04, 2017 9:01 pm

I know there is an up to date solution in the form of a TOLB
..but I found a small cache of these chips ..
..about 10 in total.
A remnant of the old days when I was much more active repairing C64s.
They have never seen solder.and have sat in anti static foam sponge for years.
As yet untested but I'd assume some if not all are still good.
so ..I'm curious as to scarcity
Chances are I shall need one for my C64 reloaded MKII when it eventually arrives

rgds
VS



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eslapion
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Re: Just how rare are 8701 chips these days ?

Post by eslapion » Tue Sep 05, 2017 4:44 pm

8701 chips aren't so rare because they are often salvaged from dead C64.

The problem is, just like the PLA 906114-01, they fail often because of their internal chemistry and the heat they generate. The 8701 is nowhere near as bad as genuine Commodore PLAs, the 8701 draws about 25mA of power (from the 5Vdc) vs 95mA for the PLA.

TOLB as well as other substitutes made by competitors use modern CMOS technology which has virtually no life span limit.

Would you be impressed if you had just found a cache of antique incandescent light bulbs when you can get diode lights which consume less power, don't cause heat and can virtually last forever ?
Last edited by eslapion on Tue Sep 05, 2017 9:47 pm, edited 1 time in total.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: Just how rare are 8701 chips these days ?

Post by ViperSan » Tue Sep 05, 2017 4:47 pm

Thanks for the reply ..
very informative.

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Gyro Gearloose
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Re: Just how rare are 8701 chips these days ?

Post by Gyro Gearloose » Wed Sep 06, 2017 12:31 am

eslapion wrote:
Tue Sep 05, 2017 4:44 pm
Would you be impressed if you had just found a cache of antique incandescent light bulbs
Yes.

Image
The price one pays for pursuing any profession, or calling, is an intimate knowledge of its ugly side.

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Re: Just how rare are 8701 chips these days ?

Post by ViperSan » Wed Sep 06, 2017 2:17 am

Well ..there is another side to LEDs
My customers are certainly not impressed when their TV backlight fails within 18 months from new ..
Whereas CRTs lasted for 20 years plus..
We are all well aware that Tech doesn't need to fail ..but manufactures build failure into their products..
Known as churn ..how else they gonna sell you another.
Yes we have the tech ..but no it isn't used for the consumers benefit .
watch this for info ..
it's an education.
https://www.youtube.com/watch?v=D56nut_9e8s

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eslapion
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Re: Just how rare are 8701 chips these days ?

Post by eslapion » Wed Sep 06, 2017 4:34 am

Gyro Gearloose wrote:
Wed Sep 06, 2017 12:31 am

Image
IIRC this particular light bulb was on display at Ottawa's museum of science and technology when we were there around 1999.
ViperSan wrote:
Wed Sep 06, 2017 2:17 am
My customers are certainly not impressed when their TV backlight fails within 18 months from new ..
Whereas CRTs lasted for 20 years plus..
I thought it was cold cathode lighting that had such problems.

FYI, I bought a brand new Trinitron Sony monitor back in 1999 and it died in 2003 so CRTs are definitely not immune to early failures.

Maybe I'm not a good businessman but I built absolutely no early failure mechanism in what I sell. I didn't get a single early generation Behr-Bonz (2008) to fix.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: Just how rare are 8701 chips these days ?

Post by ViperSan » Wed Sep 06, 2017 12:02 pm

Whilst I celebrate and greatly appreciate what inovators such as eslapion do for us to keep these beautiful old computers working ..
I do think we should be aware of what went before ..and celebrate the 'old' as well.
Here is a link to the 'full' conspiracy documentary ...and is something everyone _should_ be aware of imo.
https://www.youtube.com/watch?v=ZKLip7Q_Y0s
If you get time ..do watch it.
We have the Technologly we can rebuild him ...stronger ..faster ..etc
But rarely do..without a price tag..and rubbishing our planet.
lol

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Gyro Gearloose
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Re: Just how rare are 8701 chips these days ?

Post by Gyro Gearloose » Wed Sep 06, 2017 11:36 pm

eslapion wrote:
Wed Sep 06, 2017 4:34 am
IIRC this particular light bulb was on display at Ottawa's museum of science and technology when we were there around 1999.
I hope they unglued the kid's hands from it before they put it on display... or turned it on.
The price one pays for pursuing any profession, or calling, is an intimate knowledge of its ugly side.

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eslapion
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Re: Just how rare are 8701 chips these days ?

Post by eslapion » Wed Sep 06, 2017 11:37 pm

@ViperSan
Yes, I remember the 1000 hours conspiracy about light bulbs (Phoebus cartel).

The funny thing is, this documentary contains no subtitles and I can understand both the English and the French parts.

What is not said about the Livermore light bulb is that because of it's low temperature filament, it is incredibly low efficiency. Not a substitute for solid state lighting.

On another note... you may like this one: https://www.youtube.com/watch?v=p-I8GDklsN4

Back to the Commodore 8701 subject:
I think Commodore expected the C64 and everything related to it to be completely obsolete and useless only a few years after it's introduction. I am amazed there are so many working C64 after more than 30 years.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: Just how rare are 8701 chips these days ?

Post by ViperSan » Fri Sep 08, 2017 2:53 pm

Well fwiw ..
I have now recently resurrected 3x VIC20
I actually have 4 ..but not enough VIC chips to go round..
doh!
One of which was an early board AC only 2 pronged transformer..
& 3 x breadbin C64 ..
Im currently working to bring 2 Plus 4s back from the dead ..
both now bring up a display ...but
1 has several sluggish keys..
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 ?
The other does not respond to key presses ..and sometimes phantom characters appear as if by magic..
anyone had this and know which chip(s) might be suspect ?

Finally I have a C16 ..which was almost depopulated chip wise ..
No idea if this will ever live again ...but I'm working on it..
It is also missing the RF modulator..
Chances are this was used as a donor unit before being tossed in a bin.
This I can live without if need be..though it would be nice to have it complete..
rgds
VS

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