Hi John,

So I guess my best bet is to find someone who program chips for me on acasion when I need them done.

It's more about what you want to do. If you're going to program a lot or if you need them when you need them, programming yourself makes more sense. If it's an occasional device to program and you don't want to invest in a good quality programmer or take the time to learn how to program EPROMs reliably; it's probably best left to someone who either knows what they're doing or has equipment that does it correctly.

BR
Dennis

 

Hi Bill,

Or get an ancient DOS computer with a parallel port.

We didn't get that far. He bought a programmer that doesn't work. The Willem software can be made to work on Win8, but you have to fiddle with io.dll if you have to use a parallel port emulator.

Getting an old Windows computer with a parallel port is the easiest thing to do. That's what I do. Going back to DOS won't help because the newer versions of the program won't run from a command line.

BR
Dennis

 

My computer has a parallel port and running on xp. My programmer works , I bought it not knowing the model I had so I didn't know what software to use. I found out it was made by mcumall and its not what I need to program m27c1001 chips.

 

Hi John,

If you bought from Mcumall, see if you can return it. I told them years ago about the problems with that design and they said they sold it to give their customers more options and would be phasing it out with their "True USB" programmers. The Enhanced Universal isn't suitable for anything. A PCB5 can be made to work.

If you run a parallel port programmer, make sure you disable XP's printer polling feature. Otherwise, you'll experience unexpected writes.

BR
Dennis

 

Or get an ancient DOS computer with a parallel port.

You don't have to go that far back.

The various free recycling groups on Yahoo are a good source of older machines.

 

The programmer I have now will read the chip but when I try to program a chip it gives me a error and a bunch of 0's and something about the buffer. I figured if it will read it then it should write it.

 

I have a pic of the programmer in one of my beginning posts , it has the buttons to change the voltage .

 

Hi John,

...when I try to program a chip it gives me a error and a bunch of 0's and something about the buffer.

Show the error message. It gives the offending address, what was in the buffer to be programmed, and what was programmed.

I figured if it will read it then it should write it.

Bad assumption. Your programmer has no VCC options, so can only program EPROMs that specify a programming VCC of 5V (only old, small EPROMs) which are programmed open loop (no margin checking). 1Mb EPROMs require VCC=6.25V to program. And your nominal 5V VCC is whatever the USB port is providing which can be 4.5-5.5V.

BR
Dennis

 

Curious, what on Earth still uses old EPROMs and why would you want to program them?

 

I read a post on here where a person slowed down the spead of the programming using the two slide bars don't remember what they are , how did it work for him

 

For some amateur radio tnc's

 

Curious, what on Earth still uses old EPROMs and why would you want to program them?

Many vintage electronic instruments use EPROMs and since they're only spec'ed to hold their charge for 10-20 years, they sometimes need to be refreshed. One of my cars uses an EPROM in the ECU, and I've programmed EPROMs for several GM and motorcycle ECU's.

I still use them in circuits that need static look up tables. I also use NVRAM, PROM, and EEPROM. The more tools you have in your toolbox, the better craftsman you can be...

I also use SSI to design control circuits whereas most would simply go for a microcontroller/software solution.

BR
Dennis

 

I read a post on here where a person slowed down the spead of the programming using the two slide bars don't remember what they are , how did it work for him

That won't work in your case. 1Mb EPROMs require VCC=6.25V during programming to insure sufficient programming margin. If you only check margin to 5V, you can't be certain it will work at high or low VCC.

The only parts that can be programmed at VCC=5V are 32Kb (maybe 64Kb) and smaller devices where the programming pulse is 50mS and they guaranteed that the threshold voltage would be higher than normal operating conditions. 1Mb parts can program an address in as little as 100uS.

The max that you can set the programming pulse is 12.5mS, so you need to check margin explicitly even for devices that use an open loop method.

BR
Dennis

 

Do you know of anyone that has a programmer that will for my needs.

 

Hi John,

What is your budget and how much time are you willing to invest in learning to program EPROMs reliably?

BR
Dennis

 

Maybe $50-$75. More if I need to. If I'm going to do it I would like to do it correctly.

 

hi,

I have a Willem 5.0 programmer. I have bought that from ebay. I am able to read almost all types of chips, but when trying to program, I can do that only for newer models.

I have tried with a 27C512 and 27C256 and success. But for an older 27128 and 2716, the the VPP under load drops to around 9V.

There is a potentiometer for modifying the VPP but under load, no matter how I change that, the VPP remains at ~9V. Without load, it goes up/down as I turn the potentiometer.

I have tried both USB power or external power (I have a good PSU from a laptop that can provide max 5A).

So my question is how can I get a steady VPP? I need 12.5 or 21.5 (for some old Soviet 2716).

I have learned that I should change the inductor from the step-up converter but what characteristics should I look after?
In the PCB3.0 schematic it states that the inductor is 100uH. I do not know if on 5.0 is the same.

On ebay there are plenty of inductors for sale, like this:
http://www.ebay.com/itm/10pcs-1mH-I...849?pt=LH_DefaultDomain_0&hash=item23528c4d19


Are they any good?

 

Hi payty,

Welcome to the forum! You should start your own thread because your programmer is significantly different than the one in the original post...

I have a Willem 5.0 programmer. I have bought that from ebay. I am able to read almost all types of chips, but when trying to program, I can do that only for newer models.

I have tried with a 27C512 and 27C256 and success. But for an older 27128 and 2716, the the VPP under load drops to around 9V.

You'll find that you can program most CMOS EPROMs (though not reliably), but will have difficulty reading or programming NMOS.

There is a potentiometer for modifying the VPP but under load, no matter how I change that, the VPP remains at ~9V. Without load, it goes up/down as I turn the potentiometer.

You have more problems than VPP drop. All of the Willem variants except the Willem 4.1 with the optional relay will have a significant VCC drop that will prevent reliable operation for high current draw devices, including some of the larger CMOS FLASH that can draw 80mA from VCC.

I have tried both USB power or external power (I have a good PSU from a laptop that can provide max 5A).

I don't recommend using the USB power option. The voltage could be as low as 4.5V and still be within spec. To program most EPROMs, you require VCC of 6-6.5V. Using an external power source will use the 5V regulator on the programmer (assuming there is one) and that would give you the VCC voltage settings required for programming.

So my question is how can I get a steady VPP? I need 12.5 or 21.5 (for some old Soviet 2716).

I have learned that I should change the inductor from the step-up converter but what characteristics should I look after?

Most PCB3 variants use a molded inductor that saturates at low current, it needs to be replaced.

In the PCB3.0 schematic it states that the inductor is 100uH. I do not know if on 5.0 is the same.

You can read the markings on the inductor or post a high resolution picture of the step up regulator and surrounding components.

On ebay there are plenty of inductors for sale, like this: [snip] Are they any good?

If you have a molded inductor, it's better than what you have; the 270mA saturation current might be sufficient.

Once you address the VPP drop problem, the next problem you'll need to address is the VCC drop. 2716 are spec'ed for Icc max of 100mA. At that current, the VCC switch on your programmer will have a voltage drop of 0.5-2V. At the low end of that range, you drop below the recommended operating voltage for 5V EPROMs. That voltage drop will make verifying reliable programming impossible, read will be marginal.

 

Hi John,

Here's a link with some information on your programmer. It was originally posted on willem.org, but that site is defunct (after Willem passed away). EZo resurrected some of the old posts and is hosting them read-only on his website (ezoflash.com).

http://www.ezoflash.com/willem_info/forum.php?show=topic&topic=1145286403

I am the user DL in those postings. I used to be an administrator on willem.org.

BR
Dennis

Hi! Denis
I read most of your posts about willem programmer but I do not know how to e-mail you. I am interested on the board of willem version 4.1 and ask you if you have the schematic diagram, the user manual and the components placement I found on internet but no schematics.

Thanks
Best regards
Nelson

 

No manual , no markings on the board to tell me anything.

Download this willem EPROM programmer manual in PDF.