Re: Article related to 5116 scope [1 Attachment]
Ah yes, the Radio Electronics article. I was a subscriber and remember reading it. I think I have that issue in storage. On Mon, 21 Jan 2013 20:13:59 -0800 (PST), Carlos Urbina Pacheco <curbinap@...> wrote: I found this article today. Perhaps someone finds it of interest.
Regards,
Carlos
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Article related to 5116 scope
I found this article today. Perhaps someone finds it of interest.
Regards,
Carlos
|
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Stick an edge card connector on the bottom of some perforated board
and you could use point to point wiring. I have built ISA cards that
way.
If you can find them, I think NEC uDP444 SRAMs which draw 5 microamps
maximum in standby mode could be used as replacements for the original
AMD AM91L24 SRAMs.
Unfortunately besides swapping some of the TTL LS logic for HCT logic,
some other circuit changes would be required to get true micropower
standby operation.
If it is not available online somewhere already, I can probably
arrange for copies of the newer firmware at some point. I originally
planned on backing mine up and replacing the unreliable MOSTEK ROMs
but the 7854 I picked up did not use them. At the time I was not even
aware that there was a newer hardware revision.
toggle quoted message
Show quoted text
On Mon, 21 Jan 2013 21:48:55 -0000, cleyson@... wrote: Hi David
I had wondered about upgrading my 7854 with newer RAM and ROM boards and was even considering laying out new PCB's. I havn't looked at pricing for a small run of PCB's but it is probably cheaper than buying new Tektronix boards.
I don't think it would be worth trying to modify an old RAM card for battery backup as the standby current is probably too high. Will look into it at a later date.
Chris
--- In TekScopes@..., "David C. Partridge" wrote:
David,
Do you have the schematics of this later memory board? I think it would be a great modification to change the earlier board to do this too.
Regards,
David Partridge
-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of David
Sent: 21 January 2013 16:35
To: TekScopes@...
Subject: Re: [TekScopes] Re: 7854 RAM magic
I believe the behavior you are seeing is normal.
I have the most recent 7854 hardware version which has a lithium backup battery mounted on the memory board. On the back of the mainframe where the connections for external memory backup power used to be, there is a toggle switch which selects between self test and memory backup.
In self test mode, the memory is cleared every time the mainframe is powered up and the self test is run.
In memory backup mode, the self test is skipped and the mainframe starts in stored mode. "SELF TEST" on the ID screen is replaced with "NV MEMORY".
On Mon, 21 Jan 2013 15:20:24 -0000, "bogroca"
wrote:
Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the NORMAL behaviour when power-up with the battery back-up connected?
The manuals, both the op and service, say on page 1-7 and 1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up applied)..."
Bet never gets back to the topic, WITH the memory back-up applied.
Any thoughts?
Best regards,
Bogdan
--- In TekScopes@..., "Herbert" wrote:
Hi Bogdan,
it is normal for the HM62256B to keep the data down to approx. 1V.
I think what zou see is, that the system does not recognnize the power off phase .
Herbert
--- In TekScopes@..., "bogroca" wrote:
Hi all,
After replacing the ROMs (document to come soon), I got on to the RAM.
Replaced all 91L24 chips with 2x HM62256B (that's all I had at hand), thinking to first try out the simple SRAM and then, if all OK, to move over to NVSRAM like DS1230.
First boot with the new chips went fine, but then, to my surprise, from the second boot on, it bypassed the self-check routines, booting (seem correctly) directly into the scope mode. Quickly digitized a wave and display it. All good. Powered off and then on again...
...It booted directly in the "stored" mode with the right wave displayed.
I can assure you that the first impulse was to check if the battery backup is present. The second was to see if, by mistake, I did not inserted the NVRAM chips instead. None of this was true. It must be some energy stored in the caps. Tested some more and got to fully discharge in about 3-4 minutes, when it boots with the self-check.
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird.
Sorry for the long post and thank you inadvance!
Bogdan
------------------------------------
Yahoo! Groups Links
|
Hi David
I had wondered about upgrading my 7854 with newer RAM and ROM boards and was even considering laying out new PCB's. I havn't looked at pricing for a small run of PCB's but it is probably cheaper than buying new Tektronix boards.
I don't think it would be worth trying to modify an old RAM card for battery backup as the standby current is probably too high. Will look into it at a later date.
Chris
toggle quoted message
Show quoted text
--- In TekScopes@..., "David C. Partridge" wrote:
David,
Do you have the schematics of this later memory board? I think it would be a great modification to change the earlier board to do this too.
Regards,
David Partridge
-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of David
Sent: 21 January 2013 16:35
To: TekScopes@...
Subject: Re: [TekScopes] Re: 7854 RAM magic
I believe the behavior you are seeing is normal.
I have the most recent 7854 hardware version which has a lithium backup battery mounted on the memory board. On the back of the mainframe where the connections for external memory backup power used to be, there is a toggle switch which selects between self test and memory backup.
In self test mode, the memory is cleared every time the mainframe is powered up and the self test is run.
In memory backup mode, the self test is skipped and the mainframe starts in stored mode. "SELF TEST" on the ID screen is replaced with "NV MEMORY".
On Mon, 21 Jan 2013 15:20:24 -0000, "bogroca"
wrote:
Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the NORMAL behaviour when power-up with the battery back-up connected?
The manuals, both the op and service, say on page 1-7 and 1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up applied)..."
Bet never gets back to the topic, WITH the memory back-up applied.
Any thoughts?
Best regards,
Bogdan
--- In TekScopes@..., "Herbert" wrote:
Hi Bogdan,
it is normal for the HM62256B to keep the data down to approx. 1V.
I think what zou see is, that the system does not recognnize the power off phase .
Herbert
--- In TekScopes@..., "bogroca" wrote:
Hi all,
After replacing the ROMs (document to come soon), I got on to the RAM.
Replaced all 91L24 chips with 2x HM62256B (that's all I had at hand), thinking to first try out the simple SRAM and then, if all OK, to move over to NVSRAM like DS1230.
First boot with the new chips went fine, but then, to my surprise, from the second boot on, it bypassed the self-check routines, booting (seem correctly) directly into the scope mode. Quickly digitized a wave and display it. All good. Powered off and then on again...
...It booted directly in the "stored" mode with the right wave displayed.
I can assure you that the first impulse was to check if the battery backup is present. The second was to see if, by mistake, I did not inserted the NVRAM chips instead. None of this was true. It must be some energy stored in the caps. Tested some more and got to fully discharge in about 3-4 minutes, when it boots with the self-check.
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird.
Sorry for the long post and thank you inadvance!
Bogdan
------------------------------------
Yahoo! Groups Links
|
postscript: Q719 is open.
Jerry Massengale
toggle quoted message
Show quoted text
-----Original Message-----
From: jerry massengale
To: tekscopes ; TekScopes2
Sent: Mon, Jan 21, 2013 3:31 pm
Subject: [TekScopes] Arcing cap on 7514
?
Hi,
I powered up the 7514 I received this morning and found there is a .03uf cap arcing on the z-axis card. The cap is connected between Pin MH and ground. I did not leave it on long enough to measure the voltage. There is a small open place where the cap arcs.
I have not received my cd with the manual yet. Can someone tell me what the circuit is? The cap is in parallel with a 10k 1/4w carboncomp resistor.
Jerry Massengale
|
Hi,
I powered up the 7514 I received this morning and found there is a .03uf cap arcing on the z-axis card. The cap is connected between Pin MH and ground. I did not leave it on long enough to measure the voltage. There is a small open place where the cap arcs.
I have not received my cd with the manual yet. Can someone tell me what the circuit is? The cap is in parallel with a 10k 1/4w carboncomp resistor.
Jerry Massengale
|
Re: 2230 No readout FIXED
On Mon, 21 Jan 2013 10:39:51 -0500, Bert Haskins <bhaskins@...> wrote: On 12/19/2012 05:39 PM, David wrote:
. . .
The problem could be as simple as an IC
Close!
or connector popping out of
its socket because of thermal cycling.
Sorry about the late reply:
While searching for the answer to this, I happened to touch the probe
to one of the pins on one of the eproms ( CE I think ).
When the probe made contact, the 7-segment readout changed from
a "8" to blank and the readout appeared.
Removing, cleaning the eprom and socket fixed the problem.
This was not one of the crappy TI sockets it is a Berg/Auget style dual
side wipe.
First time I've seen a problem in one of those. It might be worth reflowing the solder connections on that socket. Maybe there was a cold or failed solder joint. Take the IC out if you do that though so the tinning on the leads does not solder it into the socket.
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Re: 2230 No readout FIXED
On 01/21/2013 12:10 PM, DaveC wrote:
?
> Removing, cleaning the eprom and socket fixed the
problem.
> This was not one of the crappy TI sockets it is a
Berg/Auget style dual side wipe.
> First time I've seen a problem in one of those.
One of my standard troubleshooting techniques is to use a
small screwdriver to lift all socketed ICs (not so much as
to remove a pin, just to wipe the contact) and reseat
them. Just a small twist of the 'driver at each end then
reseat.
Dave
I agree, and had done that but in this case only removing and
cleaning worked.
I guess that I just got lucky in that the probe tip made the missing
connection long
enough to "shout out" the real problem.
|
On Mon, 21 Jan 2013 16:44:41 -0000, "David C. Partridge" <david.partridge@...> wrote:
Do you have the schematics of this later memory board? I think it would be a great modification to change the earlier board to do this too.
I assume that the self test/memory backup switch function relies on the newer firmware. I think the hard part would be copying the new firmware to the old memory layout. The schematic and layout for the newest board are in the same directory: The SRAM is always backed up in the newest revision. The mainframe's startup behavior is controlled by just the switch on the back. The switch connects into line K7 of the front panel and calculator keyboard interface: The Artek documentation for the 7854 covers all of the hardware revisions as far as I know.
|
Re: 2230 No readout FIXED
Removing, cleaning the eprom and socket fixed the problem. This was not one of the crappy TI sockets it is a Berg/Auget style dual side wipe. First time I've seen a problem in one of those. One of my standard troubleshooting techniques is to use a small screwdriver to lift all socketed ICs (not so much as to remove a pin, just to wipe the contact) and reseat them. Just a small twist of the 'driver at each end then reseat. Dave
|
David,
Do you have the schematics of this later memory board? I think it would be a great modification to change the earlier board to do this too.
Regards,
David Partridge
toggle quoted message
Show quoted text
-----Original Message----- From: TekScopes@... [mailto:TekScopes@...] On Behalf Of David Sent: 21 January 2013 16:35 To: TekScopes@... Subject: Re: [TekScopes] Re: 7854 RAM magic I believe the behavior you are seeing is normal. I have the most recent 7854 hardware version which has a lithium backup battery mounted on the memory board. On the back of the mainframe where the connections for external memory backup power used to be, there is a toggle switch which selects between self test and memory backup. In self test mode, the memory is cleared every time the mainframe is powered up and the self test is run. In memory backup mode, the self test is skipped and the mainframe starts in stored mode. "SELF TEST" on the ID screen is replaced with "NV MEMORY". On Mon, 21 Jan 2013 15:20:24 -0000, "bogroca" <bogroca@...> wrote: Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the NORMAL behaviour when power-up with the battery back-up connected?
The manuals, both the op and service, say on page 1-7 and 1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up applied)..."
Bet never gets back to the topic, WITH the memory back-up applied.
Any thoughts?
Best regards,
Bogdan
--- In TekScopes@..., "Herbert" wrote:
Hi Bogdan,
it is normal for the HM62256B to keep the data down to approx. 1V.
I think what zou see is, that the system does not recognnize the power off phase .
Herbert
--- In TekScopes@..., "bogroca" wrote:
Hi all,
After replacing the ROMs (document to come soon), I got on to the RAM.
Replaced all 91L24 chips with 2x HM62256B (that's all I had at hand), thinking to first try out the simple SRAM and then, if all OK, to move over to NVSRAM like DS1230.
First boot with the new chips went fine, but then, to my surprise, from the second boot on, it bypassed the self-check routines, booting (seem correctly) directly into the scope mode. Quickly digitized a wave and display it. All good. Powered off and then on again...
...It booted directly in the "stored" mode with the right wave displayed.
I can assure you that the first impulse was to check if the battery backup is present. The second was to see if, by mistake, I did not inserted the NVRAM chips instead. None of this was true. It must be some energy stored in the caps. Tested some more and got to fully discharge in about 3-4 minutes, when it boots with the self-check.
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird.
Sorry for the long post and thank you inadvance!
Bogdan
------------------------------------ Yahoo! Groups Links
|
I believe the behavior you are seeing is normal. I have the most recent 7854 hardware version which has a lithium backup battery mounted on the memory board. On the back of the mainframe where the connections for external memory backup power used to be, there is a toggle switch which selects between self test and memory backup. In self test mode, the memory is cleared every time the mainframe is powered up and the self test is run. In memory backup mode, the self test is skipped and the mainframe starts in stored mode. "SELF TEST" on the ID screen is replaced with "NV MEMORY". On Mon, 21 Jan 2013 15:20:24 -0000, "bogroca" <bogroca@...> wrote: Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the NORMAL behaviour when power-up with the battery back-up connected?
The manuals, both the op and service, say on page 1-7 and 1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up applied)..."
Bet never gets back to the topic, WITH the memory back-up applied.
Any thoughts?
Best regards,
Bogdan
--- In TekScopes@..., "Herbert" wrote:
Hi Bogdan,
it is normal for the HM62256B to keep the data down to approx. 1V.
I think what zou see is, that the system does not recognnize the power off phase .
Herbert
--- In TekScopes@..., "bogroca" wrote:
Hi all,
After replacing the ROMs (document to come soon), I got on to the RAM.
Replaced all 91L24 chips with 2x HM62256B (that's all I had at hand), thinking to first try out the simple SRAM and then, if all OK, to move over to NVSRAM like DS1230.
First boot with the new chips went fine, but then, to my surprise, from the second boot on, it bypassed the self-check routines, booting (seem correctly) directly into the scope mode. Quickly digitized a wave and display it. All good. Powered off and then on again...
...It booted directly in the "stored" mode with the right wave displayed.
I can assure you that the first impulse was to check if the battery backup is present. The second was to see if, by mistake, I did not inserted the NVRAM chips instead. None of this was true. It must be some energy stored in the caps. Tested some more and got to fully discharge in about 3-4 minutes, when it boots with the self-check.
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird.
Sorry for the long post and thank you inadvance!
Bogdan
|
Re: Missing pages in Tek 7854 waveform calculator manual
Hi David,
In my pdf section 6 the missing pages are
6-16, 17, 18, 19, 22 (done), 23 (done), 26,27, 34, 35.
There might be a more complete pdf, so perhaps wait or Herbert.
Albert
toggle quoted message
Show quoted text
--- In TekScopes@..., David Holland wrote:
Ok...
No biggie, if someone wants to let me know, I can scan those as well.
I don't particularly want to scan the whole thing, it isn't tiny.....
David
On Mon, Jan 21, 2013 at 10:00 AM, Albert wrote:
Be prepared for more requests David, several other pages are missing as well ;=).
Albert
I'll email it directly in two seconds, since attachments tend to be dropped
from the mailing list.
I just scanned the two pages into one tif file. Chopping it up is left as
an exercise for the reader. ;-)
If someone else wants a copy let me know, I can mail it..
David
------------------------------------
Yahoo! Groups Links
|
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird. Yes, it is normal.
|
Re: 2230 No readout FIXED
On 12/19/2012 05:39 PM, David wrote:
?
On Wed, 19 Dec 2012 17:00:50 -0500, Bert Haskins
<bhaskins@...>
wrote:
>On 12/19/2012 02:34 PM, David wrote:
>>
>> Just to be clear, the STORE/NON-STORE button in
the top row all the
>> way to the right does not do anything either?
>>
>It slightly changes the horizontal calibration.
You mean it shifts the horizontal position a bit? That
makes sense
because 1 pole of the STORE/NON-STORE switch changes the
horizontal
position on the analog side to set it up for the digital
display. That
is independent of anything the digital side of the
oscilloscope does.
The other pole enables DSO mode in the kernel.
>> Make sure to check the position of the
STORAGE/READOUT INTENSITY
>> control just to the right of the CRT.
>>
>> Since the readout is completely missing in analog
mode but the analog
>> oscilloscope apparently operates, if the above
checks out, then I
>> would suspect the digital board is
malfunctioning. You are probably
>> going to need a service manual to proceed.
>>
>This is like the "readout toggle on off" except that
it is just off..
>doesn't toggle.
And the storage display never shows a trace because it
never
activates, right?
The readout toggle function on the 2230 only applies to
the readout
and not to the digital storage trace so it is possible to
disable the
readout but still have a digital storage trace visible
with one
control.
>So I guess I'll have to check that out in the manual.
The service manual has a whole procedure for checking just
the kernel
(page 6-8) which includes the microprocessor, clock, and
address latch
but you probably need another working oscilloscope to do
it and it is
only going to reveal if the kernel is working or should be
working. I
*think* it should be possible to diagnose it using the
2230 working in
analog mode two traces at a time.
On the other hand, checking the kernel is probably a very
good place
to start, after the power supply voltages, because a
malfunction there
could easily cause the problems you are seeing.
The problem could be as simple as an IC
Close!
or connector popping out of
its socket because of thermal cycling.
Sorry about the late reply:
While searching for the answer to this, I happened to touch the
probe
to one of the pins on one of the eproms ( CE I think ).
When the probe made contact, the 7-segment readout changed from
a "8"? to blank and the readout appeared.
Removing, cleaning the eprom and socket fixed the problem.
This was not one of the crappy TI sockets it is a Berg/Auget style
dual side wipe.
First time I've seen a problem in one of those.
|
Re: Missing pages in Tek 7854 waveform calculator manual
Ok...
No biggie, if someone wants to let me know, I can scan those as well.
I don't particularly want to scan the whole thing, it isn't tiny.....
David
toggle quoted message
Show quoted text
On Mon, Jan 21, 2013 at 10:00 AM, Albert <aodiversen@...> wrote: Be prepared for more requests David, several other pages are missing as well ;=).
Albert
I'll email it directly in two seconds, since attachments tend to be dropped
from the mailing list.
I just scanned the two pages into one tif file. Chopping it up is left as
an exercise for the reader. ;-)
If someone else wants a copy let me know, I can mail it..
David
------------------------------------
Yahoo! Groups Links
|
Hi Bogdan,
I did not trz up to now, but I think, it will goon with working with
all the parameters from before and with the waveforms retained !
Herbert
?
Am 21-01-2013 15:20, schrieb bogroca:
toggle quoted message
Show quoted text
?
Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the
NORMAL behaviour when power-up with the battery back-up
connected?
The manuals, both the op and service, say on page 1-7 and
1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up
applied)..."
Bet never gets back to the topic, WITH the memory back-up
applied.
Any thoughts?
Best regards,
Bogdan
--- In TekScopes@...,
"Herbert" wrote:
>
> Hi Bogdan,
>
> it is normal for the HM62256B to keep the data down
to approx. 1V.
> I think what zou see is, that the system does not
recognnize the power off phase .
>
> Herbert
>
>
> --- In TekScopes@...,
"bogroca" wrote:
> >
> > Hi all,
> >
> > After replacing the ROMs (document to come
soon), I got on to the RAM.
> >
> > Replaced all 91L24 chips with 2x HM62256B
(that's all I had at hand), thinking to first try out the
simple SRAM and then, if all OK, to move over to NVSRAM
like DS1230.
> >
> > First boot with the new chips went fine, but
then, to my surprise, from the second boot on, it bypassed
the self-check routines, booting (seem correctly) directly
into the scope mode. Quickly digitized a wave and display
it. All good. Powered off and then on again...
> >
> > ...It booted directly in the "stored" mode with
the right wave displayed.
> >
> > I can assure you that the first impulse was to
check if the battery backup is present. The second was to
see if, by mistake, I did not inserted the NVRAM chips
instead. None of this was true. It must be some energy
stored in the caps. Tested some more and got to fully
discharge in about 3-4 minutes, when it boots with the
self-check.
> >
> > One question, before proceeding further: is it
normal to bypass the self-check if the contents of the RAM
is still present, like when the backup battery is present?
I find this a little weird.
> >
> > Sorry for the long post and thank you inadvance!
> >
> > Bogdan
> >
>
|
Hi Herbert,
I assumed that myself.
The question that bothers me, is that about what is the NORMAL behaviour when power-up with the battery back-up connected?
The manuals, both the op and service, say on page 1-7 and 1-3 respectively:
"Power-up Conditions
When the 7854 is turned on (without the memory back-up applied)..."
Bet never gets back to the topic, WITH the memory back-up applied.
Any thoughts?
Best regards,
Bogdan
toggle quoted message
Show quoted text
--- In TekScopes@..., "Herbert" wrote:
Hi Bogdan,
it is normal for the HM62256B to keep the data down to approx. 1V.
I think what zou see is, that the system does not recognnize the power off phase .
Herbert
--- In TekScopes@..., "bogroca" wrote:
Hi all,
After replacing the ROMs (document to come soon), I got on to the RAM.
Replaced all 91L24 chips with 2x HM62256B (that's all I had at hand), thinking to first try out the simple SRAM and then, if all OK, to move over to NVSRAM like DS1230.
First boot with the new chips went fine, but then, to my surprise, from the second boot on, it bypassed the self-check routines, booting (seem correctly) directly into the scope mode. Quickly digitized a wave and display it. All good. Powered off and then on again...
...It booted directly in the "stored" mode with the right wave displayed.
I can assure you that the first impulse was to check if the battery backup is present. The second was to see if, by mistake, I did not inserted the NVRAM chips instead. None of this was true. It must be some energy stored in the caps. Tested some more and got to fully discharge in about 3-4 minutes, when it boots with the self-check.
One question, before proceeding further: is it normal to bypass the self-check if the contents of the RAM is still present, like when the backup battery is present? I find this a little weird.
Sorry for the long post and thank you inadvance!
Bogdan
|
Re: Missing pages in Tek 7854 waveform calculator manual
Hi ,
thanks to all especialy to David !!!
I have included the two pages and put the file to
where we all like to download !!!
Herbert
Am 21-01-2013 12:28, schrieb Herbert:
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Show quoted text
?
Hi all out there,
in all the manual copies of the "Using the Waveform
Calculator - 7854" available on the web the pages 6-22 and
6-23 are missing.
Does somebody have a paper version and can scan those two
pages ???
I would than correct the manual and provide it to the
manuals respositories in the web !
Thanks in advance
Herbert
|
Re: Missing pages in Tek 7854 waveform calculator manual
Be prepared for more requests David, several other pages are missing as well ;=).
Albert
toggle quoted message
Show quoted text
I'll email it directly in two seconds, since attachments tend to be dropped
from the mailing list.
I just scanned the two pages into one tif file. Chopping it up is left as
an exercise for the reader. ;-)
If someone else wants a copy let me know, I can mail it..
David
|
David Hess
David C. Partridge