Sorry if this is the wrong area. But anyway...
I am trying to clone some EPROMs, and I'm wondering if its my programmer causing my grief..
I have some TMS27PC256 EPROMs, trying to clone them out. I am working to put them on some ATMEL AT27C256R chips, new from DigiKey.
Programmer is an MCUMALL GQ-4X, and an older version, not the new one. I'm also using the programmer adapter they recommended, with the jumper set to 5v.
That last part interested me, as Vcc needs to jump to 6.5, and Vpp to 13 for programming. I have NOT put it on the scope yet to check the voltages, but I may play with that yet to see what I get.
So I pull the data off the old chip (I have multiple examples, they all seem to read the same), switch over the device on the UI to the ATMEL, blank check, burn chip, verify, and everything seems fine. I install the chip onto the PCB, nothing. I put the old chips back in, works fine.
I'm wondering if my budget programmer just isn't going to cut it. Supposedly it can handle these chips, but maybe not. Sure, it seems to read them fine, but maybe it can't program? Thinking of shelling out the money for a Dataman programmer, but I'm not sure if that will fix my issue.
The programmer works just fine for cloning other chips, such as the X28C64.
Any thoughts are appreciated.