Breadboard serial port 8XC5X programmer.
(Extra chips, no regulators, and ugly too!)
An RS-232 port connection allows swapping with equipment powered on,
and removes the PC speed
variables from the programming software. It also allows use of the
device programmer with any PC
supporting a serial port, and a compatible terminal program.
Breadboard serial port 8XC5X programmer.
(Extra chips, no regulators, and ugly too!)
All of the power supplies and breaking of point-to-point wiring got
to be a pain during development so I
made up a few boards with space for the different regulators and switches/LED's
to tell me when I
might blow the chip! The only big mistake I made is that I should have
made room for a ZIF socket for the
'750/751. I made an extender W/ZIF for them, which is why the 750/751
is missing in these pics.
The '7xx has been very hard to find in less than 1000+ part lots, so
I'm converting it to Atmel chips.
Atmel 89C/87Fxx serial port programmer with
87C/Fxx or 89Cxx serial port programmer.
on-board+12V charge pump. 6V+ power.
On-board +12/12.5V dual Vcc regulator.
The red LED shows when the +Vpp is on.
The bi-color LED tells which +Vpp is selected.
I have converted the programmer to Atmel chips, but as most projects,
it is now gaining features while I am simplifying the circuit.
The current incarnation uses two AT89S8252 chips. One is the control
and the other is programmed as a "smart" 8255 PIO chip, and uses
the SPI port as the control interface. A few OpAmps supply the
various voltages and control signals for the devices being programmed.
I am also looking at adding the PIC devices to the supported devices.