June 24, 2018 - 01:23 pm|
|Hi, I don't understand the Zener Diode in your circuit. The forward voltage usually is around 0.3 Volts or so, which means, that you get 46.7 Volts on VGG. Okay so far, but how do you get 10 Volts... there is nothing connected to the pin anymore if the Diode blocks, i.e. Ground on one side and the pin on the other side. Is it with remaining charge on Vgg itself? |
May 03, 2017 - 08:12 am|
|Thanks. That saves me a lot of time drawing it out from scratch. |
May 02, 2017 - 08:47 am|
May 02, 2017 - 08:12 am|
|Did you do the schematics in Eagle? If so can you post the eagle files? |
August 30, 2014 - 02:46 pm|
|Hi Minime, I take it that you meant to say "reader part" at the end of your message. Yes indeed, to extract the reader part, look at the sections enclosed in dotted lines at the lower left of the schematic. (Unfortunately for clarity, the DB25 connectors are also drawn with dotted lines but please ignore those for the moment.) The dotted lines I mean are labeled "Optional Reader" and "Optional Reader Pwr Ctrl." To make a reader, you need what is contained in those two sections, along with the DB25F connector directly above. Then make the separate adapter cable shown on the left. The adapter cable goes from the reader board to the two parallel ports needed on your PC. Beware that many newer PCs don't have parallel ports.|
Only the +5V and -9V power supplies shown in the dotted lines are needed for the reader. If you are careful to keep those supplies off when inserting and removing the 1702A, you could leave out the "Optional Reader Pwr Ctrl" section. In that case, about the only things left on the reader board would be the 1702A socket, a couple caps and the DB25F connector. No active electronics needed!
I don't know of any reason why the existing software wouldn't work with this arrangement. Of course, the only useable command will be (R)ead. Choosing that will prompt you for a filename and a choice of ASCII or binary format. It will then read the PROM data and put it in the file.
I wish you the best of luck with your project.
August 30, 2014 - 01:02 pm|
|This is by far the best writer description I could find so far... unfortunately for me I am searching for a reader only, to keep things simple, but most on the net is either incomprehensible or includes a writer. Would it be hard to extract from the schematics only the writer part? |