INS4004D in Pro-Log M900 PROM Programmer

Ethan Dicks ethan.dicks at
Tue Aug 28 21:27:02 CDT 2007

On 8/28/07, Allison <ajp166 at> wrote:
> > As for a modified socket, I have an old "Z-80
> >Starter Kit" SBC that happens to have a built-in EPROM programmer on
> >one of the three ROM sockets.  There's a toggle switch to disconnect
> >the programming voltage, but once enabled, you simply write to the
> >address range of that EPROM socket, and after the data are presented
> >to the ROM, the circuit wiggles the programming pin to write the
> It also requires the "write pulse" to be 50milliseconds long.  Write
> is accomplished by supplying VPP (12, 21 or 26V version dependent)
> then playing the OE/ and CE/ pins.

I can entirely appreciate that.  From reading the docs, there's
nothing magical on the software end, so I'm sure the requisite logic
is in place to supply the write pulse and to gate in Vpp and twiddle
the OE/ and CE/ pins.


More information about the cctech mailing list