JuanUp
Active member
Data IO 29B Unipak and Harris 7621 & 7685 PROMs
I set the device to a Harris 7621 or 7685. When I load a .BIN file, it doesn't set the high nibble of any of the bytes of data, (0F 01 04 0E instead of 2F 91 34 AE etc.), in the programmer's RAM and returns 'CHECKSUM ERROR'. However, I set the device to an AMD 2716 and the same .BIN file loads fine in to the programmer's RAM. With the correct data loaded, I'll then switch the device to the Harris 7621 or 7685 and *BAM* the high nibble of all the bytes switch to zero in the programmer's RAM when I view it.
WHAT... THE... F... is going on? Keep in mind that I haven't read any datasheets on either chip yet. I'm venting more than anything.
Annoyed...
Juan
I set the device to a Harris 7621 or 7685. When I load a .BIN file, it doesn't set the high nibble of any of the bytes of data, (0F 01 04 0E instead of 2F 91 34 AE etc.), in the programmer's RAM and returns 'CHECKSUM ERROR'. However, I set the device to an AMD 2716 and the same .BIN file loads fine in to the programmer's RAM. With the correct data loaded, I'll then switch the device to the Harris 7621 or 7685 and *BAM* the high nibble of all the bytes switch to zero in the programmer's RAM when I view it.
WHAT... THE... F... is going on? Keep in mind that I haven't read any datasheets on either chip yet. I'm venting more than anything.
Annoyed...
Juan
