19 Nov
2014
19 Nov
'14
5:47 p.m.
Hey all --
A quick one -- what's the normal operating temperature for the old MPS6540
ROMs used in the original Commodore PETs? I noticed last night after
running mine for ~30 minutes that the ROMs were very hot, to the point of
being painful to touch.
The machine is running fine as far as I can tell -- though I haven't
verified the contents of the ROMs, BASIC runs without any apparent issues.
Voltages are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
19 Nov
19 Nov
6:02 p.m.
IME, older ROM chips can get +quite+ warm.. but 'painful' is fairly
subjective. I seem to recall ROM chips running hotter than the 6502/6510
CPU in some of my Commodore stuff.
Do you have any way to quantify the temperature? A little HS compound & a
digital cooking thermometer?
On Wed, Nov 19, 2014 at 7:47 PM, Josh Dersch <derschjo at gmail.com> wrote:
Hey all --
A quick one -- what's the normal operating temperature for the old MPS6540
ROMs used in the original Commodore PETs? I noticed last night after
running mine for ~30 minutes that the ROMs were very hot, to the point of
being painful to touch.
The machine is running fine as far as I can tell -- though I haven't
verified the contents of the ROMs, BASIC runs without any apparent issues.
Voltages are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
9:39 p.m.
On 11/19/2014, 5:47 PM, Josh Dersch wrote:
Hey all --
A quick one -- what's the normal operating temperature for the old MPS6540
ROMs used in the original Commodore PETs? I noticed last night after
running mine for ~30 minutes that the ROMs were very hot, to the point of
being painful to touch.
The machine is running fine as far as I can tell -- though I haven't
verified the contents of the ROMs, BASIC runs without any apparent issues.
Voltages are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
A fan is a good idea on older electronics. the cooler they run the
longer they last. A heat sink epoxied to the top of hot ceramic devices
is not bad either...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
11:44 p.m.
My general rule, is if cannot hold your finger on for a count of five, you
need fan directly on it (or sink, Robertson said), & experience has told
me, that one-two years life!!
John Kaur. in AZ where its hot>
On Wed, Nov 19, 2014 at 10:39 PM, John Robertson <pinball at telus.net> wrote:
On 11/19/2014, 5:47 PM, Josh Dersch wrote:
Hey all --
A quick one -- what's the normal operating temperature for the old MPS6540
ROMs used in the original Commodore PETs? I noticed last night after
running mine for ~30 minutes that the ROMs were very hot, to the point of
being painful to touch.
The machine is running fine as far as I can tell -- though I haven't
verified the contents of the ROMs, BASIC runs without any apparent issues.
Voltages are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
A fan is a good idea on older electronics. the cooler they run the
longer they
last. A heat sink epoxied to the top of hot ceramic devices is
not bad either...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
20 Nov
20 Nov
5:38 p.m.
On Wed, Nov 19, 2014 at 11:44 PM, John Kaur <digitgraph at gmail.com> wrote:
My general rule, is if cannot hold your finger on for
a count of five, you
need fan directly on it (or sink, Robertson said), & experience has told
me, that one-two years life!!
John Kaur. in AZ where its hot>
On Wed, Nov 19, 2014 at 10:39 PM, John Robertson <pinball at telus.net>
wrote:
is
Oh, very much understood. I don't really want to bandage over a problem,
though -- if these ROMs aren't *supposed* to be running hot then I'd like
to know so I can address the issue properly. If this is normal behavior
then I'll probably do something to help reduce the heat and prolong the
(already limited) life of these 6540s.
Does anyone with direct experience with 6540s have any input here?
Thanks,
Josh
On 11/19/2014, 5:47 PM, Josh Dersch wrote:
> Hey all --
>
> A quick one -- what's the normal operating temperature for the old
MPS6540
> ROMs used in the original Commodore PETs? I
noticed last night after
> running mine for ~30 minutes that the ROMs were very hot, to the point
of
> being painful to touch.
>
> The machine is running fine as far as I can tell -- though I haven't
> verified the contents of the ROMs, BASIC runs without any apparent
issues.
Voltages
are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
A fan is a good idea on older electronics. the cooler they run the
longer they
last. A heat sink epoxied to the top of hot ceramic devices not bad either...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
6:33 p.m.
On 11/20/2014, 5:38 PM, Josh Dersch wrote:
On Wed, Nov 19, 2014 at 11:44 PM, John Kaur
<digitgraph at gmail.com> wrote:
Not direct, but you should read/archive those PROM images so you can use
something like the Commodore collectors use to replace theirs when they die:
http://home.comcast.net/~medasaro/6540rom.com/6540romadapter.html
http://www.vintage-computer.com/vcforum/showthread.php?27671-How-to-read-65…
These ROMs used from 110 to a max of 150ma @ 5VDC which is 0.75W. Hmm,
how hot is that to the touch?
John :-#)#
My general rule, is if cannot hold your finger on
for a count of five, you
need fan directly on it (or sink, Robertson said), & experience has told
me, that one-two years life!!
John Kaur. in AZ where its hot>
On Wed, Nov 19, 2014 at 10:39 PM, John Robertson <pinball at telus.net>
wrote:
is
> not bad either...
Oh, very much understood. I don't really want to bandage over a problem,
though -- if these ROMs aren't *supposed* to be running hot then I'd like
to know so I can address the issue properly. If this is normal behavior
then I'll probably do something to help reduce the heat and prolong the
(already limited) life of these 6540s.
Does anyone with direct experience with 6540s have any input here?
Thanks,
Josh
On 11/19/2014, 5:47 PM, Josh Dersch wrote:
> Hey all --
>
> A quick one -- what's the normal operating temperature for the old
MPS6540
> ROMs used in the original Commodore PETs? I
noticed last night after
> running mine for ~30 minutes that the ROMs were very hot, to the point
of
> being painful to touch.
>
> The machine is running fine as far as I can tell -- though I haven't
> verified the contents of the ROMs, BASIC runs without any apparent
issues.
Voltages
are normal (just a shade under 5V).
I've not experienced ROM chips that run so very hot -- is this normal?
Thanks,
Josh
A fan is a good idea on older electronics. the cooler they run the
longer they
last. A heat sink epoxied to the top of hot ceramic devices
>> John :-#)#
>>
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
7:09 p.m.
Weeeelll..
On Thu, Nov 20, 2014 at 8:33 PM, John Robertson <pinball at telus.net> wrote:
These ROMs used from 110 to a max of 150ma @ 5VDC
which is 0.75W. Hmm, how
hot is that to the touch?
I guess that depends on whether or not you're up for a discussion of
specific heat aka heat capacity.. ;-)
But I won't be the one to start it.
3729
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