To use the PETvet in your PET, you need to remove the 6502 chip from your PET, insert the 6502 into the empty socket on the PETvet (make sure the notch is facing in the same direction as the other chips on the board), and connect the whole PETvet board into the 6502 socket.
The PETvet can be used to halt the CPU of a running PET and view the contents of its memory. This is done by controlling the PETvet microcontroller over a serial port.
The PETvet’s serial port settings are 38400 baud, N81. Connect a serial cable from the PETvet to a computer with a serial port and a terminal program of your choice, using these settings. When you start the PET, you will see a startup message on the terminal which will show you the PETvet switch settings.
At any time while the PET is running, you can halt the CPU and enter diagnostic mode by pressing a key in the terminal. You will then be presented with a menu of options for viewing the contents of the PET’s memory.
PETvet default switch settings:
|Switch 1||Switch 2||Switch 3||ROM|
|OFF||OFF||OFF||Basic 2, 40 Column, no CRTC (PET 2001)|
|OFF||OFF||ON||Basic 4.0, 40 Column, no CRTC (PET 2001)|
|OFF||ON||OFF||Basic 4.0, 80 Column, CRTC (PET 8032)|
Jumper settings and ROM contents can be customized by reprogramming the flash memory on the PETvet’s microcontroller.
To reprogram the PETvet, first remove the PETvet from the PET motherboard.
Move the programming jumper to the left into the “Program” setting as shown:
Connect the PETvet to a terminal, 38400 baud N81. Connect the PETvet to a 5v power source and a message will appear on your terminal indicating that the PETvet is in programming mode.
Start an XMODEM transfer in your terminal program and begin sending the binary that you want to reprogram the PETvet with.
Move the programming jumper back to “Run” mode, and after a second or two you will see the XMODEM transfer begin.
When the transfer is complete, your PETvet is reprogrammed and ready to go.
More details on everything coming soon..