Topics

Tek 2467B

rpoz28cam
 

Greetings,
 
Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip?  Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age.  My part has a 95 date code which might be stretching it on lifetime.  Any thoughts or discussion on this?
 
Jon
 

Tom Miller <tmiller@...>
 

Hi Jon,
 
That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery  that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.
 
 
There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.
 
Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.
 
Regards,
Tom
 
 
 
 

----- Original Message -----
From: J
Sent: Sunday, September 04, 2011 11:08 AM
Subject: [TekScopes] Tek 2467B

 

Greetings,
 
Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip?  Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age.  My part has a 95 date code which might be stretching it on lifetime.  Any thoughts or discussion on this?
 
Jon
 

 

I just recently replaced both Dallas/Maxim DS1230AB-120 NVRAMs in my
Tektronix 2440 with Simtek/Cypress STK16C88-WF45 NVRAMs. I was going
to copy the data over but while my old EPROM programmer set for a
28256 style EEPROM was able to read and write to the STK16C88 NVRAMs
it could not read the DS1230AB NVRAMs and I ended up corrupting the
data so I lost the operating hours and calibration.

I used a Weller manual desoldering tool with a vacuum pump replacing
the squeeze bulb and it worked fabulous for removing the old NVRAMs.
They practically fell off of the board and the only cleaning I did was
to wipe it down a little before putting the sockets in.

The STK16C88 NVRAMs have worked fine so far in the 2440. They use
EEPROM backup of a SRAM instead of a lithium battery and are rated for
100 years of retention and at least a million backup cycles.

Once I get the 2440 recalibrated, I will try to find the operating
hours value and fix it.

On Sun, 4 Sep 2011 08:08:04 -0700 (PDT), J <rpoz28cam@...>
wrote:

Greetings,
 
Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip?  Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age.  My part has a 95 date code which might be stretching it on lifetime.  Any thoughts or discussion on this?
 
Jon

Bob Koller
 

Yup! works fine...


From: J
To: "tekscopes@..."
Sent: Sunday, September 4, 2011 8:08 AM
Subject: [TekScopes] Tek 2467B

 
Greetings,
 
Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip?  Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age.  My part has a 95 date code which might be stretching it on lifetime.  Any thoughts or discussion on this?
 
Jon
 


gwangju3 <gwangju3@...>
 

Yes, I do it all the time.

I was thinking of offering a rebuild service on ebay for the A5 controller board but didn't think there would be much of a market for it.

Send me your old DS1225Y and I will send you a 2011 date code DS1225AD purchased directly from Maxim with your old data copied over to it for the same price as Digikey.

--Victor

--- In TekScopes@..., Bob Koller <testtech@...> wrote:

Yup! works fine...



________________________________
From: J <rpoz28cam@...>
To: "tekscopes@..." <tekscopes@...>
Sent: Sunday, September 4, 2011 8:08 AM
Subject: [TekScopes] Tek 2467B


 
Greetings,
 
Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip?  Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age.  My part has a 95 date code which might be stretching it on lifetime.  Any thoughts or discussion on this?
 
Jon
 

gwangju3 <gwangju3@...>
 

Tom,

That's the wrong part. The proper alternate for the DS1225Y is the DS1225AD (NOT THE AB). The Y and AD suffix specify the the +/- 10% VCC rating which affects the setpoint for voltage at which the internal battery is cut in and out.

The 2465B/67B/45B/55B use the DS1225Y or DS1225AD.

The digital scopes, like the later models 2430A, 2440 use the DS1230AB.

--Victor

--- In TekScopes@..., "Tom Miller" <tmiller@...> wrote:

Hi Jon,

That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.

http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AB-85+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GryGq42nW%252bYzQ%3d

There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.

Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.

Regards,
Tom




----- Original Message -----
From: J
To: tekscopes@...
Sent: Sunday, September 04, 2011 11:08 AM
Subject: [TekScopes] Tek 2467B




Greetings,

Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip? Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age. My part has a 95 date code which might be stretching it on lifetime. Any thoughts or discussion on this?

Jon

Tom Miller <tmiller@...>
 

Hi Victor,
 
Thanks for catching that. The AD part is here, same price:
 
 
I believe the AB part will still work as the 5 volts on the A5 board is more than 4.75 volts anyway. The spec for the digital 5 volts is 4.85 to 5.15 with a max p-p ripple of 150 mV. Half of the ripple (75 mV) could be below the 4.85 level and will still be above the 4.75 volt level for the AB part. Anal, I know and you should still use the 10% AD part.
 
Have a great day,
Tom
 
 
 

----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 11:26 AM
Subject: [TekScopes] Re: Tek 2467B

 

Tom,

That's the wrong part. The proper alternate for the DS1225Y is the DS1225AD (NOT THE AB). The Y and AD suffix specify the the +/- 10% VCC rating which affects the setpoint for voltage at which the internal battery is cut in and out.

The 2465B/67B/45B/55B use the DS1225Y or DS1225AD.

The digital scopes, like the later models 2430A, 2440 use the DS1230AB.

--Victor

--- In TekScopes@..., "Tom Miller" wrote:
>
> Hi Jon,
>
> That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.
>
> http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AB-85+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GryGq42nW%252bYzQ%3d
>
> There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.
>
> Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.
>
> Regards,
> Tom
>
>
>
>
> ----- Original Message -----
> From: J
> To: tekscopes@...
> Sent: Sunday, September 04, 2011 11:08 AM
> Subject: [TekScopes] Tek 2467B
>
>
>
>
> Greetings,
>
> Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip? Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age. My part has a 95 date code which might be stretching it on lifetime. Any thoughts or discussion on this?
>
> Jon
>

rpoz28cam
 

Gentlemen,
 
I appreciate the correction.. Was contemplating ordering a part today.  By the way..from the programmers point of view what is the eprom equiv number to read the data from the 1225?
64K .. but what format?  I know I don't want to corrupt my data..my scope works so perfect.. would hate to spoil it!
 
 
Jon
 

From: Tom Miller
To: TekScopes@...
Sent: Monday, September 5, 2011 10:55 AM
Subject: Re: [TekScopes] Re: Tek 2467B

 
Hi Victor,
 
Thanks for catching that. The AD part is here, same price:
 
 
I believe the AB part will still work as the 5 volts on the A5 board is more than 4.75 volts anyway. The spec for the digital 5 volts is 4.85 to 5.15 with a max p-p ripple of 150 mV. Half of the ripple (75 mV) could be below the 4.85 level and will still be above the 4.75 volt level for the AB part. Anal, I know and you should still use the 10% AD part.
 
Have a great day,
Tom
 
 
 
----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 11:26 AM
Subject: [TekScopes] Re: Tek 2467B

 
Tom,

That's the wrong part. The proper alternate for the DS1225Y is the DS1225AD (NOT THE AB). The Y and AD suffix specify the the +/- 10% VCC rating which affects the setpoint for voltage at which the internal battery is cut in and out.

The 2465B/67B/45B/55B use the DS1225Y or DS1225AD.

The digital scopes, like the later models 2430A, 2440 use the DS1230AB.

--Victor

--- In TekScopes@..., "Tom Miller" wrote:
>
> Hi Jon,
>
> That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.
>
> http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AB-85+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GryGq42nW%252bYzQ%3d
>
> There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.
>
> Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.
>
> Regards,
> Tom
>
>
>
>
> ----- Original Message -----
> From: J
> To: tekscopes@...
> Sent: Sunday, September 04, 2011 11:08 AM
> Subject: [TekScopes] Tek 2467B
>
>
>
>
> Greetings,
>
> Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip? Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age. My part has a 95 date code which might be stretching it on lifetime. Any thoughts or discussion on this?
>
> Jon
>



Tom Miller <tmiller@...>
 


Should be the same as a 2764 or 2864 pin-out. As long as you only do a read, nothing bad should happen to the original chip. But the best thing is to find the exact part in your programmer supported device list. If you go to the Mouser page you can download the datasheet for the part to see the specs and pin-outs.
 
Look for DS1225 in the device list.
 
 
 
Tom
 
 

----- Original Message -----
From: J
Sent: Monday, September 05, 2011 12:19 PM
Subject: Re: [TekScopes] Re: Tek 2467B

 

Gentlemen,
 
I appreciate the correction.. Was contemplating ordering a part today.  By the way..from the programmers point of view what is the eprom equiv number to read the data from the 1225?
64K .. but what format?  I know I don't want to corrupt my data..my scope works so perfect.. would hate to spoil it!
 
 
Jon
 

From: Tom Miller
To: TekScopes@...
Sent: Monday, September 5, 2011 10:55 AM
Subject: Re: [TekScopes] Re: Tek 2467B

 
Hi Victor,
 
Thanks for catching that. The AD part is here, same price:
 
 
I believe the AB part will still work as the 5 volts on the A5 board is more than 4.75 volts anyway. The spec for the digital 5 volts is 4.85 to 5.15 with a max p-p ripple of 150 mV. Half of the ripple (75 mV) could be below the 4.85 level and will still be above the 4.75 volt level for the AB part. Anal, I know and you should still use the 10% AD part.
 
Have a great day,
Tom
 
 
 
----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 11:26 AM
Subject: [TekScopes] Re: Tek 2467B

 
Tom,

That's the wrong part. The proper alternate for the DS1225Y is the DS1225AD (NOT THE AB). The Y and AD suffix specify the the +/- 10% VCC rating which affects the setpoint for voltage at which the internal battery is cut in and out.

The 2465B/67B/45B/55B use the DS1225Y or DS1225AD.

The digital scopes, like the later models 2430A, 2440 use the DS1230AB.

--Victor

--- In TekScopes@..., "Tom Miller" wrote:
>
> Hi Jon,
>
> That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.
>
> http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AB-85+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GryGq42nW%252bYzQ%3d
>
> There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.
>
> Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.
>
> Regards,
> Tom
>
>
>
>
> ----- Original Message -----
> From: J
> To: tekscopes@...
> Sent: Sunday, September 04, 2011 11:08 AM
> Subject: [TekScopes] Tek 2467B
>
>
>
>
> Greetings,
>
> Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip? Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age. My part has a 95 date code which might be stretching it on lifetime. Any thoughts or discussion on this?
>
> Jon
>



gwangju3 <gwangju3@...>
 

Be careful here. Most professional products will detect an invalid pin-out and not apply power and signals to the pins. But programmers like Willem and other Chinese experimenters ebay unit will happily burn out your device. Unless your programmer supports the DS12xx series from Dallas/Maxim OR you really know what you're doing be careful.

Once your DS1225Y is blown it's too late to ask for help.

--Victor

rpoz28cam
 

Hey Victor,
 
Thanks for that, I might just take you up on that offer.  Don't feel too good about sending my part out though, could get lost in the mail, etc.  Then I would have a junk 2467B and might have to go back to my virgin 465B. 
I have a pretty good programmer that has served very well over the years and if worse comes to worse.. I could always bread board a reader via the spec sheet and read the device myself, keeping in mind I would do a test run on a blank 1225 nvram.  I might have to visit my old classic IMSAI 8080 bit twiddler box.. has pretty cool epprom/rom reader. 
 
 
Jon
 

From: gwangju3
To: TekScopes@...
Sent: Monday, September 5, 2011 12:49 PM
Subject: [TekScopes] Re: Tek 2467B

 
Be careful here. Most professional products will detect an invalid pin-out and not apply power and signals to the pins. But programmers like Willem and other Chinese experimenters ebay unit will happily burn out your device. Unless your programmer supports the DS12xx series from Dallas/Maxim OR you really know what you're doing be careful.

Once your DS1225Y is blown it's too late to ask for help.

--Victor



gwangju3 <gwangju3@...>
 

You should be able to read the DS1225Y directly. If it's a good programmer it should have support for DS1225Y/AD.

--Victor

--- In TekScopes@..., J <rpoz28cam@...> wrote:

Hey Victor,
 
Thanks for that, I might just take you up on that offer.  Don't feel too good about sending my part out though, could get lost in the mail, etc.  Then I would have a junk 2467B and might have to go back to my virgin 465B. 
I have a pretty good programmer that has served very well over the years and if worse comes to worse.. I could always bread board a reader via the spec sheet and read the device myself, keeping in mind I would do a test run on a blank 1225 nvram.  I might have to visit my old classic IMSAI 8080 bit twiddler box.. has pretty cool epprom/rom reader. 
 
 
Jon
 

From: gwangju3 <gwangju3@...>
To: TekScopes@...
Sent: Monday, September 5, 2011 12:49 PM
Subject: [TekScopes] Re: Tek 2467B


 
Be careful here. Most professional products will detect an invalid pin-out and not apply power and signals to the pins. But programmers like Willem and other Chinese experimenters ebay unit will happily burn out your device. Unless your programmer supports the DS12xx series from Dallas/Maxim OR you really know what you're doing be careful.

Once your DS1225Y is blown it's too late to ask for help.

--Victor

Tom Miller <tmiller@...>
 

The Willem supports the Dallas DS1225 from the menu.
 
One other thing - I would recommend installing one of the high quality low profile machined pin 28 pin sockets. That way, your heirs will be able to change the chip after the next 20 years pass.
 
 
:)
 
Tom
 
 
 

----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 1:49 PM
Subject: [TekScopes] Re: Tek 2467B

 

Be careful here. Most professional products will detect an invalid pin-out and not apply power and signals to the pins. But programmers like Willem and other Chinese experimenters ebay unit will happily burn out your device. Unless your programmer supports the DS12xx series from Dallas/Maxim OR you really know what you're doing be careful.

Once your DS1225Y is blown it's too late to ask for help.

--Victor

 

Based on the DS1225 and 2764 pinouts, that should work unlike the
DS1230 and 27256 where the A14 and Write Enable pin are swapped which
is bad news.

On Mon, 05 Sep 2011 12:26:47 -0400, "Tom Miller"
<tmiller@...> wrote:

Should be the same as a 2764 or 2864 pin-out. As long as you only do a read, nothing bad should happen to the original chip. But the best thing is to find the exact part in your programmer supported device list. If you go to the Mouser page you can download the datasheet for the part to see the specs and pin-outs.

Look for DS1225 in the device list.



Tom


----- Original Message -----
From: J
To: TekScopes@...
Sent: Monday, September 05, 2011 12:19 PM
Subject: Re: [TekScopes] Re: Tek 2467B




Gentlemen,

I appreciate the correction.. Was contemplating ordering a part today. By the way..from the programmers point of view what is the eprom equiv number to read the data from the 1225?
64K .. but what format? I know I don't want to corrupt my data..my scope works so perfect.. would hate to spoil it!


Jon



From: Tom Miller <tmiller@...>
To: TekScopes@...
Sent: Monday, September 5, 2011 10:55 AM
Subject: Re: [TekScopes] Re: Tek 2467B



Hi Victor,

Thanks for catching that. The AD part is here, same price:

http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AD-150+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GrXtqhiF8bABI%3d

I believe the AB part will still work as the 5 volts on the A5 board is more than 4.75 volts anyway. The spec for the digital 5 volts is 4.85 to 5.15 with a max p-p ripple of 150 mV. Half of the ripple (75 mV) could be below the 4.85 level and will still be above the 4.75 volt level for the AB part. Anal, I know and you should still use the 10% AD part.

Have a great day,
Tom



----- Original Message -----
From: gwangju3
To: TekScopes@...
Sent: Monday, September 05, 2011 11:26 AM
Subject: [TekScopes] Re: Tek 2467B



Tom,

That's the wrong part. The proper alternate for the DS1225Y is the DS1225AD (NOT THE AB). The Y and AD suffix specify the the +/- 10% VCC rating which affects the setpoint for voltage at which the internal battery is cut in and out.

The 2465B/67B/45B/55B use the DS1225Y or DS1225AD.

The digital scopes, like the later models 2430A, 2440 use the DS1230AB.

--Victor

--- In TekScopes@..., "Tom Miller" <tmiller@...> wrote:
>
> Hi Jon,
>
> That works fine. Many (most) EPROM programmers can read and write to the DS1225 chip. The new NVRAM chips start with a fresh battery that is not connected until the first application of 5 volts to the chip. It would be the DS1225AB-xxx. Mouser has them for <$22.
>
> http://www.mouser.com/ProductDetail/Maxim-Integrated-Products/DS1225AB-85+/?qs=sGAEpiMZZMutXGli8Ay4kC27Vf1CC6GryGq42nW%252bYzQ%3d
>
> There is a copy of one in the files section that has good checksums and can be used to test only as the calibration will not be good for any given scope.
>
> Be sure to use good desoldering tools as there are internal tracks to the chip that can be damaged if you pull the plating out of the pad.
>
> Regards,
> Tom
>
>
>
>
> ----- Original Message -----
> From: J
> To: tekscopes@...
> Sent: Sunday, September 04, 2011 11:08 AM
> Subject: [TekScopes] Tek 2467B
>
>
>
>
> Greetings,
>
> Just thinking ahead here, has anyone on here ever removed the DS1225Y nvram from the A5 controller,copying the data from within using eprom reader/programmer and saving to a new DS1225Y chip? Digikey has them for around $25 -- such a deal! I am wondering if this is possible as an option versus sending the scope in for a complete cal hoping they will understand that the existing part has some age. My part has a 95 date code which might be stretching it on lifetime. Any thoughts or discussion on this?
>
> Jon
>






gwangju3 <gwangju3@...>
 

Most 2764 PROMs take a +12.5V pulse on the /P line (which is /WE on the DS12225Y). Kiss your DS1225Y goodbye.

--Victor

Tom Miller <tmiller@...>
 

Correct. You do not want to program it as a 2764 as that would be fatal. But no harm will be done to read it.
 
Most current cheap programmers will do the DS1225 correctly though.
 
Tom
 

----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 6:38 PM
Subject: [TekScopes] Re: Tek 2467B

 

Most 2764 PROMs take a +12.5V pulse on the /P line (which is /WE on the DS12225Y). Kiss your DS1225Y goodbye.

--Victor

gwangju3 <gwangju3@...>
 

Agreed, I verified on one of my programmers. It will read correctly, but I wouldn't recommend writing to a DS1225Y as a 2764.

--Victor

--- In TekScopes@..., "Tom Miller" <tmiller@...> wrote:

Correct. You do not want to program it as a 2764 as that would be fatal. But no harm will be done to read it.

Most current cheap programmers will do the DS1225 correctly though.

Tom

----- Original Message -----
From: gwangju3
To: TekScopes@...
Sent: Monday, September 05, 2011 6:38 PM
Subject: [TekScopes] Re: Tek 2467B



Most 2764 PROMs take a +12.5V pulse on the /P line (which is /WE on the DS12225Y). Kiss your DS1225Y goodbye.

--Victor

rpoz28cam
 

lol :) grin
Tom,
Well im not quite that old but you never know.  Yes I plan on installing a Augat lowprofile machine pin socket, thats a must!
 
Thank you,
 
Jon
 

From: Tom Miller <tmiller@...>
To: TekScopes@...
Sent: Monday, September 5, 2011 2:19 PM
Subject: Re: [TekScopes] Re: Tek 2467B

 
The Willem supports the Dallas DS1225 from the menu.
 
One other thing - I would recommend installing one of the high quality low profile machined pin 28 pin sockets. That way, your heirs will be able to change the chip after the next 20 years pass.
 
 
:)
 
Tom
 
 
 
----- Original Message -----
From: gwangju3
Sent: Monday, September 05, 2011 1:49 PM
Subject: [TekScopes] Re: Tek 2467B

 
Be careful here. Most professional products will detect an invalid pin-out and not apply power and signals to the pins. But programmers like Willem and other Chinese experimenters ebay unit will happily burn out your device. Unless your programmer supports the DS12xx series from Dallas/Maxim OR you really know what you're doing be careful.

Once your DS1225Y is blown it's too late to ask for help.

--Victor



 

Well, you would not want to write to it. The problem with the DS1230
and 27256 though is that if you read from it then A14 will toggle the
WE line and corrupt the contents. Reading the DS1225 as a 2764 does
not suffer from that problem.

In my case, I started out using the 28256 setting which should have
worked for the DS1230 but did not even though it did work with the
Simtek equivalent.

On Mon, 05 Sep 2011 22:38:01 -0000, "gwangju3" <gwangju3@...>
wrote:

Most 2764 PROMs take a +12.5V pulse on the /P line (which is /WE on the DS12225Y). Kiss your DS1225Y goodbye.

--Victor

rpoz28cam
 

David,
 
Thats why when in doubt about addressing the device, wire up a bread board with all the data, address and control lines as per specification.  I know it can be complicated but all this stuff can get that way at times.
The write enable line should never be allowed to do anything while working with such a rare programmed device such as in the 2467
 
 
 
Jon
 

From: David
To: TekScopes@...
Sent: Monday, September 5, 2011 7:40 PM
Subject: Re: [TekScopes] Re: Tek 2467B

 
Well, you would not want to write to it. The problem with the DS1230
and 27256 though is that if you read from it then A14 will toggle the
WE line and corrupt the contents. Reading the DS1225 as a 2764 does
not suffer from that problem.

In my case, I started out using the 28256 setting which should have
worked for the DS1230 but did not even though it did work with the
Simtek equivalent.

On Mon, 05 Sep 2011 22:38:01 -0000, "gwangju3" <gwangju3@...>
wrote:

>Most 2764 PROMs take a +12.5V pulse on the /P line (which is /WE on the DS12225Y). Kiss your DS1225Y goodbye.
>
>--Victor
>