Cheapest way to erase UV-erasable chips

D

David Murphy

Guest
I'm using some spare chips sitting around to build a PIC 12c509-based game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
 
In article <6JSdnXUfwNQKL3qiRVn-gQ@comcast.com>,
"David Murphy" <glibdud@hotmail.com> wrote:

I'm using some spare chips sitting around to build a PIC 12c509-based game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
For absolute cheapest, set 'em out in full sunlight with their little
windows uncovered for a while. Total cost: $however much it costs you to
walk 'em outside. The sun's a good enough UV source to take care of them
for you if you've got some patience. Experiment for the exact timing for
your chips - You can't (that I know of, anyway) "over-erase" them, but
you can "under-erase", leaving traces of whatever data they previously
held - Burn a test pattern into them, set 'em out for a day, then see if
the pattern is still readable. If you get anything other than a wiped
chip, set it back out and let it "cook" some more, then do the verify
again. Repeat until you figure out exactly how long it takes to clear
your particular chips to their initial empty state, then add a goodly
bit of extra cooking time, "just to be sure".

--
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Hi Don,

For absolute cheapest, set 'em out in full sunlight with their little
windows uncovered for a while. Total cost: $however much it costs you to
walk 'em outside. The sun's a good enough UV source to take care of them
for you if you've got some patience. Experiment for the exact timing for
your chips - You can't (that I know of, anyway) "over-erase" them, but
you can "under-erase", leaving traces of whatever data they previously
held - Burn a test pattern into them, set 'em out for a day, then see if
the pattern is still readable. If you get anything other than a wiped
chip, set it back out and let it "cook" some more, then do the verify
again. Repeat until you figure out exactly how long it takes to clear
your particular chips to their initial empty state, then add a goodly
bit of extra cooking time, "just to be sure".
Click to expand...
Forget it. I would take weeks if not months of bright noon sunshine
to deliver the necessary UV radiation to the chips.

To the OP: There are lots of cheap UV erasers out there, buy one.
Especially if you doing some microcontroller projects, this will
easily pay off. I have a quite cheap UV eraser, it takes 3 minutes
to erase a 12C508.

HTH
Wolfgang
 
The absolute easiest way out of this, would be to
switch to flash (-F-) parts...

Jan-Erik.


David Murphy wrote:
I'm using some spare chips sitting around to build a PIC 12c509-based game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
 
"David Murphy" <glibdud@hotmail.com> schreef in bericht
news:6JSdnXUfwNQKL3qiRVn-gQ@comcast.com...
I'm using some spare chips sitting around to build a PIC 12c509-based
game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece
of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only
options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
David,

Are you sure you're on the right way? An UV-erasable 12C509 is more
expensive a cheap UV-eraser. A home made flash programmer can be less
expensive then the eraser. Programming (and development)software is
available on the net. Free. (For instance look at:
http://www.voti.nl/e_index.html
but it's not the only one.) F-parts are widely available and cheap.

If you have enough time and patience, direct sunlight will do the erasing
job. Don't protect the components behind a window because the window pane
will block most of the UV you need. Can't say anything about the time you
need. Depends highly on your geografical position and on the local weather.
(On Iceland you are out of luck these days.)

I ever bought a Philips TUV lamp. (200-240V, 6W E5.) It was meant for
desinfection purposes but it erased common EPROMS within an hour.

petrus



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Checked by AVG anti-virus system (http://www.grisoft.com).
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In article <6JSdnXUfwNQKL3qiRVn-gQ@comcast.com>,
David Murphy <glibdud@hotmail.com> wrote:
-I'm using some spare chips sitting around to build a PIC 12c509-based game.
-The key word for this project is low-budget.

Understood. However if your time costs anything, I have a suggestion.

-
-I'm not set up for doing PIC assembly code debugging work. The only piece of
-equipment I have is a home-made chip programmer. Since I'm going for
-lowest-cost, an emulator is obviously out of the question. The only options
-I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
-version.

No. There is a third option... it's coming.

-
-So that leads to my question: What's the cheapest way I can erase a UV
-erasable chip? I've never dealt with them before, so I don't really know
-what it takes (besides a relatively expensive machine).

Simple. Don't. Here's the solution:

Use another chip. Specifically the 12F629. It's the same form factor as
the 12C509, is flash programmable, has more memory, and more timers, runs
faster, and costs about the same ($1.83 a pop according to digikey) as
the 12C509.

Since you stated above that you'd have to buy, why not buy a chip that
simplifies your project, not complicates it?

BTW UV erasure isn't really expensive. All you need is a clear germicidal
UV flourescent bulb in a standard ballast. I successfully used a 4 in.
bulb in a ballast bought from the home depot. Just be sure to put it all
in a lightproof box.

But since I use Flash PICs for everything now, I haven't used it in years.

BAJ
 
In article <pJUFb.3$R27.9073765@news.salzburg-online.at>,
Wolfgang Mahringer <wolfgang.mahringer@sbg.at> wrote:
-Hi Don,
-
-> For absolute cheapest, set 'em out in full sunlight with their little
-> windows uncovered for a while. Total cost: $however much it costs you to
-> walk 'em outside. The sun's a good enough UV source to take care of them
-> for you if you've got some patience. Experiment for the exact timing for
-> your chips - You can't (that I know of, anyway) "over-erase" them, but
-> you can "under-erase", leaving traces of whatever data they previously
-> held - Burn a test pattern into them, set 'em out for a day, then see if
-> the pattern is still readable. If you get anything other than a wiped
-> chip, set it back out and let it "cook" some more, then do the verify
-> again. Repeat until you figure out exactly how long it takes to clear
-> your particular chips to their initial empty state, then add a goodly
-> bit of extra cooking time, "just to be sure".
-
-Forget it. I would take weeks if not months of bright noon sunshine
-to deliver the necessary UV radiation to the chips.
-
-To the OP: There are lots of cheap UV erasers out there, buy one.
-Especially if you doing some microcontroller projects, this will
-easily pay off. I have a quite cheap UV eraser, it takes 3 minutes
-to erase a 12C508.

Just to reiterate my other post: if you don't already have the chips in hand,
buy 12F629 parts, which are more powerful, flash programmable, and the
same form factor as the 12C50X parts at the same price. Spend your money on
chips, not erasers. Plus development is faster because they near instantly
erase.

BAJ
 
In article <3FE81F4B.4052B47@aaa.com>,
Jan-Erik =?iso-8859-1?Q?S=F6derholm?= <aaa@aaa.com> wrote:
The absolute easiest way out of this, would be to
switch to flash (-F-) parts...
Click to expand...
Bingo! The 12F629 is the same price, more powerful, and are flash programmable.

BAJ
 
So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
Ditch the 12Cs and get a 12F629. For the price of that single chip you
will never be able to (re)program the 12Cs.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
PICmicro chips, programmers, consulting
 
Thanks. It appears switching to an electronically-erasable processor is the
jury's decision here, and I probably will do that for future projects. For
this one, though, I'm just trying to use some old parts I have laying
around, which include a few 12c509s. I think I'm going to see if I can track
down a germicidal UV bulb locally. If not, then I may just change my plans
and go with a different processor.

Thanks for the suggestions, all.

--

"Byron A Jeff" <byron@cc.gatech.edu> wrote in message
news:bs9k85$n0p@cleon.cc.gatech.edu...
In article <6JSdnXUfwNQKL3qiRVn-gQ@comcast.com>,
David Murphy <glibdud@hotmail.com> wrote:
-I'm using some spare chips sitting around to build a PIC 12c509-based
game.
-The key word for this project is low-budget.

Understood. However if your time costs anything, I have a suggestion.

-
-I'm not set up for doing PIC assembly code debugging work. The only piece
of
-equipment I have is a home-made chip programmer. Since I'm going for
-lowest-cost, an emulator is obviously out of the question. The only
options
-I have are to buy a bunch of disposable OTP 12c509 chips, or a
UV-erasable
-version.

No. There is a third option... it's coming.

-
-So that leads to my question: What's the cheapest way I can erase a UV
-erasable chip? I've never dealt with them before, so I don't really know
-what it takes (besides a relatively expensive machine).

Simple. Don't. Here's the solution:

Use another chip. Specifically the 12F629. It's the same form factor as
the 12C509, is flash programmable, has more memory, and more timers, runs
faster, and costs about the same ($1.83 a pop according to digikey) as
the 12C509.

Since you stated above that you'd have to buy, why not buy a chip that
simplifies your project, not complicates it?

BTW UV erasure isn't really expensive. All you need is a clear germicidal
UV flourescent bulb in a standard ballast. I successfully used a 4 in.
bulb in a ballast bought from the home depot. Just be sure to put it all
in a lightproof box.

But since I use Flash PICs for everything now, I haven't used it in years.

BAJ
Click to expand...
 
Hi
You can make the code on a flash pic (F84 F62X)
Just remember the 2 call, and port the ram adr after you code are working
you can make you own inc file and use portb for GPIO
Sorry for my english
KR
Henrik
"David Murphy" <glibdud@hotmail.com> skrev i en meddelelse
news:6JSdnXUfwNQKL3qiRVn-gQ@comcast.com...
I'm using some spare chips sitting around to build a PIC 12c509-based
game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece
of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only
options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
 
So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
A germicide bulb and a spare lamp fixture. I have a 12" fluorescent bulb
holder and I picked up a germicide bulb for $4 off eBay.

Keep in mind you'd need to build an enclosure to keep all the UV ray inside.
Unlike conventional black light I(which is long wave and does little to
EPROM) germicide bulb (commonly called shortwave UV) is quite dangerous and
can cause permanet eye damage. You could build a small wooden case and
install an inline reed relayoltage and current rating or it'd melt) on it
and magnet on the door to shut off the UV lamp when the case is opened.

If you don't have fluorescent holder, you could pick one from Walmart for
about $10. Just make sure the bulb you got and the holder are compatible.
And 12" is pretty long, can zap a dozen EPROM at a time. The time it takes
to erase depends on the model and size of the EPROM so you'll have to
experiment.
 
David Murphy wrote:
I'm using some spare chips sitting around to build a PIC 12c509-based game.
The key word for this project is low-budget.

I'm not set up for doing PIC assembly code debugging work. The only piece of
equipment I have is a home-made chip programmer. Since I'm going for
lowest-cost, an emulator is obviously out of the question. The only options
I have are to buy a bunch of disposable OTP 12c509 chips, or a UV-erasable
version.

So that leads to my question: What's the cheapest way I can erase a UV
erasable chip? I've never dealt with them before, so I don't really know
what it takes (besides a relatively expensive machine).
Click to expand...
Here's what I do.
I prototype everything on a 16F877A with a serial bootloader.
It's got extra ports for keyboard and display functions.
Makes it extremely fast to change/debug the program.
I put debug.print statements to the lcd to help me get unconfused
about my code.
As long as you don't forget and try to use a hardware
function that doesn't exist on the target chip, you should be ok.

Walling made some cheap eprom erasers. DigiKey has 'em.
Can find 'em cheap at swap meets.
mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
David Murphy wrote:

Thanks. It appears switching to an electronically-erasable processor is the
jury's decision here, and I probably will do that for future projects. For
this one, though, I'm just trying to use some old parts I have laying
around, which include a few 12c509s. I think I'm going to see if I can track
down a germicidal UV bulb locally. If not, then I may just change my plans
and go with a different processor.

Thanks for the suggestions, all.



If you go with the UV bulb, remember it has to also have a ballast.
Click to expand...

Good luck
 
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