31st Mar 2021, 11:10 am | #141 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,587
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Re: The Transam Triton Personal Computer
No, Germany. Three of the four devices I ordered from there were OK and one faulty, which was replaced immediately when I reported the problem. As I mentioned they were actually the AMD version (AM9111) which until recently were ealier to get hold of than 2111s but they were never especially cheap.
In one of the threads lying around here there is an Arduino based 2111 tester which I can track down if you want to try it, but it sounds like you already have some means of testing SRAMS, at least 2114s, from the way you mentioned that you had tested some of those at both low speed and 'real' Triton speed. |
31st Mar 2021, 11:34 am | #142 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
Posts: 125
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Re: The Transam Triton Personal Computer
Quote:
Is there still stock at the Germany seller ? |
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31st Mar 2021, 11:47 am | #143 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
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Re: The Transam Triton Personal Computer
Good system, techniques like that are so much easier when everything in the target system is in sockets. Maybe you can verify your 2111s in the same way, assuming there are already some fitted of course.
I won't be able to check that seller until I get home, perhaps one of the others who bought from the same German source can have a look and point you to it if there is any remaining stock. |
31st Mar 2021, 11:54 am | #144 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
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Re: The Transam Triton Personal Computer
I just found an old link but the original German seller doesn't seem to have any, sorry. Those I do see here in the UK and around the world generally seem prohibitively expensive.
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31st Mar 2021, 12:17 pm | #145 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
Posts: 125
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Re: The Transam Triton Personal Computer
Quote:
I still got to check out the Video Memory on the Triton it 7 x 2102-2 giving 1k a massive of 64 chars by 16 lines, unfortunately these chips in my Triton are soldered in. |
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31st Mar 2021, 5:00 pm | #146 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
Posts: 1,364
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Re: The Transam Triton Personal Computer
I bought my 2102 from insa_electronics on the bay and they still have some listed in case you have any failures.
As regards 2111 then I got mine from utsource - the prices are not too bad but, shipping and import duty (usually £15 on top of shipping) make small orders impractical. https://www.utsource.net/sch/AM9111.html |
31st Mar 2021, 7:37 pm | #147 | |
Pentode
Join Date: Mar 2021
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Re: The Transam Triton Personal Computer
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31st Mar 2021, 10:10 pm | #148 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: The Transam Triton Personal Computer
As mine was a reproduction board the difference was baked in so not a trivial change perhaps - U25 is is an extra LS138 instead of one of the RAM chips and U26 is a LS08 instead of another and U16-U19 are then rewired.
Here is the relevant bit of the diagram I was supplied with the board.... for those following along the original circuit is on the bottom left of Page 30 of the ETI article. |
31st Mar 2021, 11:41 pm | #149 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
Quote:
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1st Apr 2021, 11:35 am | #150 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
Quote:
Hall sensor chip close up Hall Sensor module Hall sensor front side close up They are very small, the two large rectangles in the chip close up photo must be the sensor itself. |
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2nd Apr 2021, 2:48 am | #151 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,444
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Re: The Transam Triton Personal Computer
Thanks for those - Rather unexpected to see the bare sensor IC die in such detail.
Unfortunately, it seems the clear glob-top makes it difficult to see much under it very well, but I am thinking that these weren't actually wire bonded but wire either soldered-down Surface-mount style. Or possibly attached with silver-loaded conductive epoxy - which often seems to crack with age, sometimes after not too long a period. But still in all cases, not too easy to re-attach one. I did have another thought about the pulses from these - Do they produce a (different) pulse when released? Otherwise - if they only give a single pulse when pressed - then there would be no way of knowing if key had been released or was being held-down. And so you wouldn't be able to have any auto-repeat on keys being held down making any scrolling via cursor keys or movement in any games etc. software a bit difficult. |
6th Apr 2021, 12:23 pm | #152 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
Quote:
On the Keyboard there is a TTL 7403 of which one of the outputs (pin 3) is dead so yet another TTL chip that has suffered, so thats 6 TTL chips so far. I thought the TTL 74xxx logic family was very robust ? |
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6th Apr 2021, 4:19 pm | #153 | |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
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Re: The Transam Triton Personal Computer
Quote:
Well TTL IC's normally are fairly robust - compared to MOS types (especially more complex Memory / Processor / custom gate array etc. devices) Although it does seem that your PSU may have gone a bit over-voltage at some point, so may be lucky if it is mostly TTL IC's that have failed and not too many expensive & rarer larger MOS ones. |
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8th Apr 2021, 3:45 pm | #154 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
Quote:
I found another usb microscope today, took another close up of the hall sensor chip looks good check it out Hall effect keyboard sensor chip Do you think it was soldered-down Surface-mount style as I might have ago to see if I can re-solder one. |
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8th Apr 2021, 4:06 pm | #155 |
Octode
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Location: Northampton, Northamptonshire, UK.
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Re: The Transam Triton Personal Computer
That's a really good image of the top-surface (even better than previous one)
And it looks like there's 4 'via' holes at the corners that have either filled with conductive epoxy or solder - no evidence of specialist bond-wire pads at least! Can you get a similar close-up photo of the underside of this 'chip' / the ceramic alumina substrate's pads ? You could try to see if it's solder, to see if it melts - but need to be careful, as pads can leech away if heated by just a soldering-iron tip and aren't protected with tin-plating etc. And ceramic substrate really needs heating with a background heater / hot air, as it's a very good thermal conductor so makes soldering with just an iron quite difficult. Plus, if pads on underside don't extend beyond edges of the chip, then it can't really be fitted using a soldering iron, but would require solder-paste and hot air, or very small amounts of conductive-epoxy. |
8th Apr 2021, 4:15 pm | #156 |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
I added another close up of the chip with the glue stuff still on, it looks like the glue stuff gets on the underside between the chip ant the ceramic mini board.
Hall sensor with glue stuff on |
8th Apr 2021, 5:22 pm | #157 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
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Re: The Transam Triton Personal Computer
Quote:
https://sites.google.com/view/transa...ensor-module-6 https://sites.google.com/view/transa...ensor-module-7 https://sites.google.com/view/transa...ensor-module-8 I have solder-paste and hot air soldering station had to solder one of those surface mount usb connectors on a external hard drive may be it will work. |
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8th Apr 2021, 7:29 pm | #158 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
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Re: The Transam Triton Personal Computer
Well that does appear quite strange, in that there doesn't appear to be any pads on the underside of the chip/die.
And that there's just a 'via' hole thorough it from the top surface. So it seems like something conductive is dropped down the holes to the substrate below - as you can see the circular marks on the pads of that (which I presume aren't holes through the substrate itself?) And I presume the holes in the die aren't just filled with the covering clear glob-top (Although maybe they are effectively plated all the way down, and only the bottom part attaches to the substrate - possibly be just being forced into some conductive epoxy on the pads - or possibly solder paste and reflowed). As I can't see it being very easy to force solder or conductive epoxy down from the top of the chip. |
8th Apr 2021, 9:13 pm | #159 | |
Pentode
Join Date: Mar 2021
Location: Liphook, Hampshire, UK
Posts: 125
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Re: The Transam Triton Personal Computer
Quote:
From the photo I assume the pins which connect to many things are the power rails, so the top two. |
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9th Apr 2021, 12:59 am | #160 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
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Re: The Transam Triton Personal Computer
If you look at the 4 'via' holes, one is offset a bit from corners of a rectangle.
And the photo of the ceramic substrate you posted,has these marks in the same arrangement, so there is only 1 rotation when all 4 connections will line-up with the existing marks on the pads. Plus I notice from the previous photo, that there is a shiny, solder-like, fill of the chip's 'via' hole connections. But they do have a very flat top, rather than a classic dome top of solder joints on circular pads. |