HP 3456A multimeter ROMS gone bad

Guest
I'm looking for ROM images for an HP 3456A multimeter.
Mine has a bad ROM. steevjanpan@hotmail.com

By the way, if you have this meter I advise that you
back up your roms. The old Mostek ROMS have been
known to go sour after 20 or so years. Same goes
for the Genrad Digibridges etc.

If I can't get lucky here, then I have to blow $100 on
another meter on eBay so I can dupe the roms.

Sorry about the crosspost, but you folks are most likely
to own a 3456A and to have this info.
 
steevjanpan@hotmail.com wrote...
I'm looking for ROM images for an HP 3456A multimeter.
Mine has a bad ROM. steevjanpan@hotmail.com

By the way, if you have this meter I advise that you
back up your roms. The old Mostek ROMS have been
known to go sour after 20 or so years. Same goes
for the Genrad Digibridges etc.

If I can't get lucky here, then I have to blow $100 on
another meter on eBay so I can dupe the roms.

Sorry about the crosspost, but you folks are most likely
to own a 3456A and to have this info.
Click to expand...
I have two. What kind of PROM did they use? What kind
of modern EPROM / EEPROM would be used in replacement?

I wonder if the ROM program changed over time, and can
be backfitted. Also, other than opening up the insrument
and looking at IC date codes, how can one tell when it
was made, how old it is? Any way to tell from the s/n?


--
Thanks,
- Win
 
<steevjanpan@hotmail.com> wrote in message
news:s6qb61thau9gfp3bs25vva948o7im4aujo@4ax.com...
I'm looking for ROM images for an HP 3456A multimeter.
Mine has a bad ROM. steevjanpan@hotmail.com

By the way, if you have this meter I advise that you
back up your ROMs. The old Mostek ROMs have been
known to go sour after 20 or so years.
Click to expand...
EPROM chips typically guarantee 10 years operation,
and chip makers usually halve measured maxima to get a value for data
sheets.
E.g. if they run at 8 MHz, guarantee them to 4 MHz,
if they lose charge in 20 years, guarantee to 10 years.

I'd say top up your EPROMs every <10 years, to be safe.
 
Kryten wrote...
EPROM chips typically guarantee 10 years operation,
and chip makers usually halve measured maxima to get a
value for data sheets.
E.g. if they run at 8 MHz, guarantee them to 4 MHz,
if they lose charge in 20 years, guarantee to 10 years.

I'd say top up your EPROMs every <10 years, to be safe.
Click to expand...
Top-up is a nice phrase... Read the EPROM, erase it,
and re-write it.


--
Thanks,
- Win
 
On 20 Apr 2005 03:56:27 -0700, Winfield Hill
<hill_a@t_rowland-dotties-harvard-dot.s-edu> asked:

What kind of PROM did they use? What kind
of modern EPROM / EEPROM would be used in replacement?

Answer:

Meters with serial numbers HIGHER-THAN 2015A03070
contain a NEW revision of the ROMS with part number:
U5=1818-1629 U7=1818-1630 U8=1818-1631

The meter contains three 8Kx8 ROMS. These ROMS can
be read on an EPROM programmer as an MC68766, as
long as the programer strobes CS or OE when reading
each consecutive address.

They can be directly replaced with pin-compatible EPROM
MC68766 or MCM68766C35 but these too are obsolete.

EPROM 27HC641 can be used and is pin compatible, as
long as you cook the data before burning, because A10
and A12 (if I remember correctly) is swapped.

EPROM 2732 can be used if you split the data and solder
in the extra sockets and make some jumper changes etc.

EPROM 2764 can be used but a socket adapter needs to
be made.

EPROM 27256 can be used but the data needs to be cooked
and an intersocket socket adapter made.

....Stepan
 
On 20 Apr 2005 12:03:44 -0700, "JeffM" <jeffm_@email.com> wrote:

multi-post: n. a condition where the same message
is posted individually to several groups.
(1 group is listed on the Subject line of each post.)
The practice is considered to be bad netiquette.

Readers of 1 group who do not read all of the groups
do not gain from the wisdom of those in the other groups.
In addition, it is less likely that mistakes will be corrected.
It is also a bad practice
because people in 1 group will continue to respond
after the question has been adequately answered in another group.
Click to expand...
Thanks for the usefull insight! Very good to know.

Stepan
 
By the way, the newer ROMS I listed below CAN be backfitted onto
older instruments.

Stepan

On Thu, 21 Apr 2005 01:40:10 GMT, steevjanpan@hotmail.com wrote:

On 20 Apr 2005 03:56:27 -0700, Winfield Hill
hill_a@t_rowland-dotties-harvard-dot.s-edu> asked:

What kind of PROM did they use? What kind
of modern EPROM / EEPROM would be used in replacement?

Answer:

Meters with serial numbers HIGHER-THAN 2015A03070
contain a NEW revision of the ROMS with part number:
U5=1818-1629 U7=1818-1630 U8=1818-1631

The meter contains three 8Kx8 ROMS. These ROMS can
be read on an EPROM programmer as an MC68766, as
long as the programer strobes CS or OE when reading
each consecutive address.

They can be directly replaced with pin-compatible EPROM
MC68766 or MCM68766C35 but these too are obsolete.

EPROM 27HC641 can be used and is pin compatible, as
long as you cook the data before burning, because A10
and A12 (if I remember correctly) is swapped.

EPROM 2732 can be used if you split the data and solder
in the extra sockets and make some jumper changes etc.

EPROM 2764 can be used but a socket adapter needs to
be made.

EPROM 27256 can be used but the data needs to be cooked
and an intersocket socket adapter made.

...Stepan
Click to expand...
 
Stepan steevjanpan@hotmail.com wrote...
By the way, the newer ROMS I listed below CAN be backfitted
onto older instruments.
Click to expand...

The NEW revision of the ROM can be backfitted? What's it do?


--
Thanks,
- Win
 
On 21 Apr 2005 03:55:52 -0700, Winfield Hill
<hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote:

The NEW revision of the ROM can be backfitted? What's it do?
Click to expand...
I suspect it's just bug fixes. Would you like a copy of the service
manual? over 300 pages and about 81 Megabytes. Painstakingly scanned
in, and with full page 11x17 schematics at 600DPI.

Stepan
 
steevjanpan@hotmail.com wrote...
On 21 Apr 2005 03:55:52 -0700, Winfield Hill
hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote:

The NEW revision of the ROM can be backfitted? What's it do?

I suspect it's just bug fixes. Would you like a copy of the service
manual? over 300 pages and about 81 Megabytes. Painstakingly scanned
in, and with full page 11x17 schematics at 600DPI.
Click to expand...
Would I, he asks, falling all over himself, picking himself up
from the ground, mouth drooling and steam rising from his nose!
Shall I send you a blank CDR in an sase? Or provide an ftp link?


--
Thanks,
- Win
 
Winfield Hill wrote...
steevjanpan@hotmail.com wrote...

On 21 Apr 2005 03:55:52 -0700, Winfield Hill
hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote:

The NEW revision of the ROM can be backfitted? What's it do?

I suspect it's just bug fixes. Would you like a copy of the service
manual? over 300 pages and about 81 Megabytes. Painstakingly scanned
in, and with full page 11x17 schematics at 600DPI.

Would I, he asks, falling all over himself, picking himself up
from the ground, mouth drooling and steam rising from his nose!
Shall I send you a blank CDR in an sase? Or provide an ftp link?
Click to expand...
In return, I'll offer a color scan of the elegant color version of
the operator's manual, plus images of the ROM from my newest 3456A.


--
Thanks,
- Win
 
<steevjanpan@hotmail.com> wrote in message
news:lrqg61hpk1lma05arvlrkg6dnchru967ec@4ax.com...
On 21 Apr 2005 03:55:52 -0700, Winfield Hill
hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote:

The NEW revision of the ROM can be backfitted? What's it do?

I suspect it's just bug fixes.
Would you like a copy of the service manual?
Over 300 pages and about 81 Megabytes.
Click to expand...
Crikey, just what kind of multimeter is it?!

Is that 81 Megs because you scanned it 600 dpi 24-bit colour and lossless
image files?

K.
 
On 22 Apr 2005 03:28:50 -0700, Winfield Hill
<hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote:

Winfield Hill wrote...

Shall I send you a blank CDR in an sase? Or provide an ftp link?
Click to expand...
ftp link is fine, or send me an email address of yours, that I can use
with http://www.yousendit.com/. Yes the ROMS would be greatly
appreciated but if that's too much to ask then I'll understand. It
would be a pitty if I didn't share the manual.

email me at snovotill@hotmail.com and not steevjanpan@hotmail.com

Stepan
 
On Fri, 22 Apr 2005 15:14:06 GMT, "Kryten"
<kryten_droid_obfusticator@ntlworld.com> wrote:

Is that 81 Megs because you scanned it 600 dpi 24-bit colour and lossless
image files?
Click to expand...
No, no. none of that nonsense. Just plain old 600DPI single bit
bitmap, compressed to PNG. That preserves the halftones in full glory.
The original manual is not in color.

Stepan
 
<steevjanpan@hotmail.com> wrote in message
news:cnnj61tng7d7bfkengd70i7no0vh0a41sj@4ax.com...
On Fri, 22 Apr 2005 15:14:06 GMT, "Kryten"
kryten_droid_obfusticator@ntlworld.com> wrote:

Is that 81 Megs because you scanned it 600 dpi 24-bit colour and lossless
image files?

No, no. none of that nonsense. Just plain old 600DPI single bit
bitmap, compressed to PNG. That preserves the halftones in full glory.
The original manual is not in colour.
Click to expand...
So it is grey scale 8-bit lossless compression, I see.

I do a fair bit of work turning scans of old documents into shiny new HTML.

800 pages is a _bit_ too much, but I tend to store the text in black and
white, which is about 8 times smaller than greyscale and the OCR software
handles. I snip out figures and circuits and store those in the form
appropriate.


I found a company that makes scanners for books: it turns pages so you just
set it going.
Very expensive, but cheaper than hiring people to scan them and is generally
only used for rare or outstanding books.

I wonder if there are companies that will scan books for you with such
machines, and how much they'd charge if I sent them my bookshelves?
 
On Sat, 23 Apr 2005 15:41:49 GMT, "Kryten"
<kryten_droid_obfusticator@ntlworld.com> wrote:

So it is grey scale 8-bit lossless compression, I see.

It's actually 1-bit grayscale. At 600DPI the halftones look great
Click to expand...
because the dot pitch of the halftones is less,so it is nicely sampled
without too much aliasing. I'm guessing that compressing a 1-bit image
into an 8-bit format works because it likely affects the dictionary
and not the data aka pointers.

As far as scanning books, I suppose one could forgo the cost of an
expensive scanner by just cutting the binding off a book and then
useing a flatbed with a document feeder.

Stepan
 
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