If any one is trying to erase a Motorola chip of the HC family and you get the error voltage message to low on the Vfp Vector Floating Point line.. therefor it will not erase ..if you check this pin it will only have 4.5v on it ..but to erase copy it needs 12v...so a easy solution is put 12v to the Vfp pin..Ignore the 4.5V leave connected it will still only be 12V on this line.
You can do this in various ways a variable power supply or link 12v from a on board 12 v regulator this will be the input pin.
You can link direct to the Vpf pin put being less than a mm apart from other pins some people can find it can be difficult to solder with out bridging..
So this pin may seen not to have any connections going any where ..but it has because the Vfp pin runs in many under the chip and out to a diode ...so meter this pin continuity to where it is going and solder the 12v to that point.
Erase
VDD/VCC 5V
RESET 5V
GROUND/VSS
RXD that is also the BKGD line.. Back Ground
Set up conections above and with the 12V to the Vfp line ..Erase/copy and done!.
All the above was done in circuit with all pins soldered..connections done with pin header on the pcb ..but if no pin header then meter pins out to connecting points and solder fine wires to these.
Hope this helps.
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