Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Nascom 2 and Tatung Einstein
6 views
Skip to first unread message
mail...@btinternet.com
Mar 8, 2013, 6:15:29 PM3/8/13
to
I wonder if there are any owners of any of these two machines here
with an interest in sharing knowledge and experiences.
I have very recently been fortunate to acquire an example of each of
them and both are in working order; the Nascom just needing the video
'snow-plough' modification.
The Nascom 1 was the first computer I built in the late 70s quickly
followed by the Nascom 2 as soon as kits became available and it was a
pang for the old machine that encouraged me to put out a request on
our local Freecycle group; not expecting any response. But in a
couple of days I was offered both machines - indeed it was a case of
you want one you take both!! Indeed my lucky day :)
Mike (itching to get back into Z80 Assembler!)
with an interest in sharing knowledge and experiences.
I have very recently been fortunate to acquire an example of each of
them and both are in working order; the Nascom just needing the video
'snow-plough' modification.
The Nascom 1 was the first computer I built in the late 70s quickly
followed by the Nascom 2 as soon as kits became available and it was a
pang for the old machine that encouraged me to put out a request on
our local Freecycle group; not expecting any response. But in a
couple of days I was offered both machines - indeed it was a case of
you want one you take both!! Indeed my lucky day :)
Mike (itching to get back into Z80 Assembler!)
Message has been deleted
mail...@btinternet.com
Mar 8, 2013, 8:54:35 PM3/8/13
to
On Fri, 08 Mar 2013 23:30:37 +0000, me <m...@example.invalid> wrote:
>On Fri, 08 Mar 2013 23:15:29 +0000, mail...@btinternet.com wrote:
>
>>I wonder if there are any owners of any of these two machines here
>>with an interest in sharing knowledge and experiences.
>>
>>I have very recently been fortunate to acquire an example of each of
>>them and both are in working order; the Nascom just needing the video
>>'snow-plough' modification.
>>
>
>I have a Nascom 2 (home built) so what is the snow plough modification and
>where can I find out more details please.
>
>The actual Nascom has not been powered up in 15 years so the state of the
>rather large capacitors in the power supply is unknown. Can anyone comment
>on these capacitors shelf life when left un powered up for years ?
>
>Regards David
David,
It's good to meet up with another owner; perhaps there are more here.
The problem is described here
http://nascom.wordpress.com/nascom/video/
The snow-dinger mentioned for the Nascom 1 is here; it gives a good
technical description of the problem and that particular solution.
http://www.80bus.co.uk/publications/magazines/Micropower-1-1.pdf
I'll locate the Nascom2 solution another time.
Regarding electrolytics they can be perfectly alright. I am working on
a restoration project that has a considerable number of large Farnell
and Weir SMPS - they had not been switched on since 1989. On the very
first one that we tested there was a small puff of smoke; that turned
out to be small Rifa paper capacitors and on inspection were found to
be cracked on most supplies so we replaced them. We took a risk and
were lucky, even the 5V 150A supplies are now powered up, on load and
not one electrolytic has failed.
I'll say more about the project another time but you can start to
build the picture from http://www.BMPG.org.uk . It does involve more
vintage computers!
Mike
>On Fri, 08 Mar 2013 23:15:29 +0000, mail...@btinternet.com wrote:
>
>>I wonder if there are any owners of any of these two machines here
>>with an interest in sharing knowledge and experiences.
>>
>>I have very recently been fortunate to acquire an example of each of
>>them and both are in working order; the Nascom just needing the video
>>'snow-plough' modification.
>>
>
>where can I find out more details please.
>
>The actual Nascom has not been powered up in 15 years so the state of the
>rather large capacitors in the power supply is unknown. Can anyone comment
>on these capacitors shelf life when left un powered up for years ?
>
>Regards David
David,
It's good to meet up with another owner; perhaps there are more here.
The problem is described here
http://nascom.wordpress.com/nascom/video/
The snow-dinger mentioned for the Nascom 1 is here; it gives a good
technical description of the problem and that particular solution.
http://www.80bus.co.uk/publications/magazines/Micropower-1-1.pdf
I'll locate the Nascom2 solution another time.
Regarding electrolytics they can be perfectly alright. I am working on
a restoration project that has a considerable number of large Farnell
and Weir SMPS - they had not been switched on since 1989. On the very
first one that we tested there was a small puff of smoke; that turned
out to be small Rifa paper capacitors and on inspection were found to
be cracked on most supplies so we replaced them. We took a risk and
were lucky, even the 5V 150A supplies are now powered up, on load and
not one electrolytic has failed.
I'll say more about the project another time but you can start to
build the picture from http://www.BMPG.org.uk . It does involve more
vintage computers!
Mike
mail...@btinternet.com
Mar 27, 2013, 7:57:59 PM3/27/13
to
Seeing as there is no specific user group/forum for Nascom owners I
have started up a Yahoo Group. So if you are of a mind to please come
and join in. It is a moderated group and I do ask that in your
request to join you tell me your name, location and very briefly your
interest in Nascom computers. This enables me to give a proper welcome
to all members and we all get to know each other.
http://groups.yahoo.com/group/nascom/
Regards,
Mike
have started up a Yahoo Group. So if you are of a mind to please come
and join in. It is a moderated group and I do ask that in your
request to join you tell me your name, location and very briefly your
interest in Nascom computers. This enables me to give a proper welcome
to all members and we all get to know each other.
http://groups.yahoo.com/group/nascom/
Regards,
Mike
Ian Field
Mar 28, 2013, 3:37:39 PM3/28/13
to
"me" <m...@example.invalid> wrote in message
news:jnskj8tiugk6du66t...@4ax.com...
>>I wonder if there are any owners of any of these two machines here
>>with an interest in sharing knowledge and experiences.
>>
>>I have very recently been fortunate to acquire an example of each of
>>them and both are in working order; the Nascom just needing the video
>>'snow-plough' modification.
>>
>
>>with an interest in sharing knowledge and experiences.
>>
>>I have very recently been fortunate to acquire an example of each of
>>them and both are in working order; the Nascom just needing the video
>>'snow-plough' modification.
>>
>
> I have a Nascom 2 (home built) so what is the snow plough modification
> and
> where can I find out more details please.
>
> The actual Nascom has not been powered up in 15 years so the state of the
> rather large capacitors in the power supply is unknown. Can anyone comment
> on these capacitors shelf life when left un powered up for years ?
Electrolytic capacitors should be "re-formed" after long storage. Ideally
> and
> where can I find out more details please.
>
> The actual Nascom has not been powered up in 15 years so the state of the
> rather large capacitors in the power supply is unknown. Can anyone comment
> on these capacitors shelf life when left un powered up for years ?
you would charge them manually from a constant current source until they
*SLOWLY* reach their rated voltage, then hold them at fixed (rated) voltage
for 24h. A much easier way is to use a variac to increase the voltage at a
few % of rated voltage every few hours.
It would probably be advisable to disconnect any 3-terminal regulators until
you're ready to power up normally.
There are various websites dedicated to old computers, one I can remember
off the cuff is Dave's old computers.
0 new messages