16F87 and BootLoader

[Kilobravo]

New to the forum, I have a 16F87 and Max3222 at 3.3V I am trying to bootload a program and everytime I do it seems like the chip becomes unresponsive. I am using the tiny bootloader. I have had good succcess with it on the 16F88 chips at 5V.
I tried to compile the Microchip Bootloader, it seems to compile fine but the PC software does not find the boot loader on the chip.
I had RB3 tied to gnd and I am not using the RB6 or RB7. I am using the internal osc at 8 mhz.

Any suggestions on what to try ? I can program the bootloader and it seems fine as soon as I program the "program" it will run fine until I reset the chip and then the chip is unresponsive. I am using CSC C v4.14. I think the C code is trashing the bootloader on reset, the bootloader and my coed works fine until I hit reset on MCLR ? Anybody know how to fix this ?

Thanks !

[temtronic]

Since you had it 'working' with the 5volt 88, then perhaps it's the RS232 interface that's causing you problems.

1) can you run the working code on an 87 with a 5V power supply ?

2) are there ANY changes in the PC platform ?

3) can a simple 'loopback using the MAX3222 work on the PC terminal prgram ?

report back and we'll scratch our heads some more !!

[Kilobravo]

I'll try and duplicate the setup on the F88 at 5volts.
It seems strange the downloaded code works fine until reset.
I think it might be a problem with the CCS code generating.
I can't get a simple flashled, hello world program to work.
It will run forever when downloaded as soon as I hit reset the chip is unresponsive and the bootloader is gone ???

[Kilobravo]

Just to close this out, I left the unused pins on the Max3222 floating. This was a bad idea. Once I grounded the unused pins I had reliable comms.

It was fine with the MAX232, but not the MAX3222.