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Re: ZX81 ULA

Posted: Tue Aug 14, 2018 6:29 pm
by Andy Rea
McKlaud wrote:
Tue Aug 14, 2018 12:51 am
Andy, it looks like you have a production line in the back garden ;) Keep going as the demand is there.

BTW finally I fitted one of your ULAs to my dead Zeddy's board and it works like a charm.
Well i have a few pcb's :lol: to keep me going, while people still buy i'll still make... Thanks for the feedback, help to make it feel worthwhile.

Regards Andy

Re: ZX81 ULA

Posted: Wed Aug 15, 2018 7:27 am
by RetroTechie
I wonder how long original ULA's would stay in working order if just stored under normal (+/- room temperature, not too dry or moist air, no direct sunlight etc). Let's say, starting with little used or New Old Stock parts. Maybe power up once or twice a year (under carefully controlled conditions) to check if still working.

Verdict on that is still out on that for IC's in general. IC's only exist since the late 50's, early 60's or so. And some of the very earliest IC's ever made are known to be still working fine (especially well-built IC's in ceramic packages etc). But Sinclair ULA's are not like military-spec, hermetically sealed ceramic package. And not full custom but gate array + customer defined interconnect layer. Similar but not the same as a mass-produced single purpose IC. :? Sealing between external pins and internal silicon die, bond wires etc may not be 100%. Or plastic used may allow gasses/pollutants from outside world to leak in. Veeeerrry little, veeeerrryy slow of course, but still some, and leaked in molecules doing their destructive job. Not to mention high-energy cosmic radiation, or whatever else may attack / degrade the inside of IC's (let's assume ESD precautions are adequate).

40 years? 50 years? 60+? Will they die en masse after a certain age? Or will there be a very 'long tail' with some specimens surviving say, a century or more?

Re: ZX81 ULA

Posted: Wed Aug 15, 2018 3:08 pm
by 1024MAK
And just as interesting as a question, will the much higher integrated, much smaller process silicon chips last longer than the older generations of chips?

So, will FPGA chips running versions of our favourite 1980s computers survive as long as the the actual 1980s computers? Will ZX80's last longer than ZX81's?

Mark

Re: ZX81 ULA

Posted: Thu Aug 16, 2018 5:52 pm
by Andy Rea
if kept in good conditions, then they will i expect outlast us so it will be the next generations problem :lol:

I wonder if in say 30 or 40 years time, people will be setting up Iphone 10 forums wondering how they are going to get parts to fix up that once faithful companion :mrgreen:

regards Anduy

Re: ZX81 ULA

Posted: Mon Aug 27, 2018 10:14 pm
by dquadros
Waiting for the next batch...

Daniel

Re: ZX81 ULA

Posted: Tue Aug 28, 2018 7:02 pm
by Andy Rea
dquadros wrote:
Mon Aug 27, 2018 10:14 pm
Waiting for the next batch...

Daniel
starting some tonight :)

regards Andy

Re: ZX81 ULA

Posted: Sat Jun 01, 2019 8:24 pm
by Papalapa
Hi Andy,

Do you know when a new batch will come?

Thank you!

Re: ZX81 ULA

Posted: Sun Jun 02, 2019 7:46 pm
by Andy Rea
Hi papalapa,

not really sure, lots of personal things going off right now, so little time left to devote to the hobby.

hopefully but no promise sometime in the next few weeks

regards Andy

Re: ZX81 ULA

Posted: Mon Jun 03, 2019 6:37 am
by 1024MAK
If we hear a shriek of joy from Barcelona, we will know why :lol:

Mark

Re: ZX81 ULA

Posted: Mon Jun 03, 2019 8:49 am
by Papalapa
1024MAK wrote:
Mon Jun 03, 2019 6:37 am
If we hear a shriek of joy from Barcelona, we will know why :lol:

Mark
For sure Mark :lol: