6502.org

That's not a Willem programmer. From the description in the auction:

• Programmer hardware design is based on Willem Programmer

Also, 18 bucks to ship it is ridiculous.

Hi billo, nice to see you in this forum..!!

I have seen that link was cool to make EPROM programmer, are you sure EEPROM will also work??

Pls tell how to make this, as where to write this program which type of computer is need..??

Will this process can hazard computer also??


Thanks

Willem type then. Better? I do not think there ever was an official product called the Willem programmer. It was just a design you could build. It has been enhanced many times since the original design came out by many folks around the world.

It's the total price that matters on eBay. For sure you can get one that cost $10 less to ship, but you'll pay $10more to get it. I'd actually prefer if they gave the programmer away for free and charged $30 to ship it. Then I would have to pay no taxes or duties.

Anyway, it is cheap and works well. That's the main point here. I have had one like this as well as the first one mentioned. They both work very well. The Willem type has the dual advantages of being less expensive and will take an external power supply. the TOP853 or Genius types have the advantage that they do not require dip switch and jumper settings, but they cost a bit more.

Hi RITESH.

How to make it should be obvious from the schematic. If not, please ask specific questions.

The program is written in Pascal. You will need a Pascal compiler. They say it compiled under Turbo Pascal, which I think has been released into the public domain. I could be wrong on this, you'll need to check.

It looks like this was done with a PC, but really, it could be modified to work with any computer.

The circuit would have to be changed slightly to do your EEPROM.
You would have to write your own software to go with it.
You would need a computer with the correct kind of printer port and
be able to control the printer port from the software.
So, for example, it would be a lot easier to do it with a QBasic program
running in DOS than trying to do it with some modern version of Windows
Absolutely yes

If you don't set things up correctly with both the hardware and the
software you might end up with the computer trying to talk to the
EEPROM at the same time the EEPROM is trying to talk to the computer,
in that case they might short each other out.



Here's a schematic for programming a similar EEPROM by hand.
Which I think would just need a couple more address lines added
for a 2864.

http://www.armory.com/~rstevew/Public/P ... M_Pgmr.gif

Again, I know nothing of this circuit except that schematic
It's just something I found while searching with Google

That schematic shows a bunch of switches on the address and
data busses but only one of every thing that goes with each switch.
For example you would need a seperate transistor, LED, transmission
gate, pull down resistor, and so on for each data line.

I'd probably try and use an octal bus driver instead of the transistors
to drive the LEDs


Here is another programmer that does some 2864s
(they are not all the same. see "Note 2: Must have Ready/Busy
pin - I use ST Microelectronics M28C64C")

http://www.armory.com/~rstevew/Public/P ... ammer.html

Hello,

I have see that .gif circuit of EEPROM programmer i think here DIP switch are used, we can replace it by 4040 chip 12 bit ring counters...........

I was thinking the same thing—to use counter ICs; but 4040's won't let you start at an arbitrary address or back up to correct mistakes.  You will want pre-setable counters like perhaps the 74xx161.  It looks like the '191 and '193 also allow counting down as well as up.  If you have the counters increment automatically after each programming pulse, you will have to debounce the "program" button.  Otherwise you will get a lot of consecutive bytes programmed with the same data where you only pressed the button once.

I would not recommend DIP switches, since they are mostly made for very few cycles of life.

Hello,

I am not getting 2864/2764 chip any other option..??

How about 28C64, or 28[C]128 or 28[C]256.  The '128 and '256 have 16Kx8 and 32Kx8 but you don't have to use all of it.  You could just ground the highest address bit for example.

Hi again,

I am sorry but the 28/24xx series is not available, some of shopkeeper said this is old part...
any other series??

By ordering through mail, is becoming very costly for me a single chip is very expensive + shipping charges....
at local store it is not available because my city is far from other city which supply in large scale products...like Delhi, Bangalore,etc..