(Topic ID: 244395)

Program 21v - 25v roms in lower voltage programmers

By Nusilor

5 years ago

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    #1 5 years ago

    So i recently orderd a tl866cs, to be disappointed when a tl866ii plus came to my door, as it only can produced a programming voltage of 18v vs 21v. I contacted the supplier to find out that the cs was no longer made and there is no way to get one.
    After buying some 28c16s from china, none of them would program, and couldn't seem to find 28c32 with cheap enough postage, I thought i would try the m2716 that i originally ordered.

    So this is how you program 21v - 25v roms in a tl866ii plus.

    So, after consulting the datasheet for the pinout and programing voltage
    Captsaure (resized).jpgCaptsaure (resized).jpg
    I decided to apply 25v to Vpp pin 21 on the rom. So i bent it out of the programmer. (Make sure you bend it out, i blew up the a transistor and driver chip by leaving it in. they are not rated for the higher voltage. This was also easily fixed by replace both of them)
    bent pin (resized).jpgbent pin (resized).jpg
    and applied 25v from an external power supply.
    jumpers (resized).jpgjumpers (resized).jpg
    Now this will give you a pin detect error, however you can turn off pin detect.
    prog (resized).jpgprog (resized).jpg
    Rom will now program as normal, and not give you any error. Hopefully there will be similar options on other programmers. This is with version 8.33 of the tl866ii plus software

    #2 5 years ago

    Nice work - you could probably stick a zif socket in it with the pin permanently out to make an adapter so as to save the eprom pin. I built an adapter to do the 2532's in the cs version of this.

    Shame they discontinued the CS, when they announced they were going to I ordered a couple extras to have around. I really like the flexibility of their software, too.

    The CS version tops out at 21 volts though, so I'd have to do this as well to do a 2716 but I just double up and use 2732's if I need a 2716.

    #3 5 years ago
    Quoted from slochar:

    The CS version tops out at 21 volts though

    The TL866A version is the same with 21 volt max and I program ST M2716 chips successfully simply by reprogramming them a few times with the same data but without erasing between reprograms.

    1 week later
    #4 5 years ago
    Quoted from slochar:

    Nice work - you could probably stick a zif socket in it with the pin permanently out to make an adapter so as to save the eprom pin.

    Yeah seting like that might be the go

    1 year later
    #5 3 years ago

    Dang, is there anything I can find here! I just ran into this problem. Problem gone. Over one year later and still informative.


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