Entering the DAP4 keyboard parameters
The DAP4 contains a minimal boot program or loader that is designed to communicate with the host machine and download it's complete workstation program.
The problem with this is that when you power on a DAP4, it just sits there. You will get the keyboard light on, and some of the LEDs in the lower right window should illuminate, but that's it.
As far as I'm aware, there is no type of self-test program for the DAP4.
If there terminal is old, there's a good change the lithium backup battery has failed and so the NVR (non volatile RAM) will have lost it's settings and the primary setting dictates the communication interface speed - without this parameter the VDU cannot load it's workstation program.
This short video sequence shows how to enter the default setting - 0815. This specifies a communication speed of 9600 baud.
The problem with this is that when you power on a DAP4, it just sits there. You will get the keyboard light on, and some of the LEDs in the lower right window should illuminate, but that's it.
As far as I'm aware, there is no type of self-test program for the DAP4.
If there terminal is old, there's a good change the lithium backup battery has failed and so the NVR (non volatile RAM) will have lost it's settings and the primary setting dictates the communication interface speed - without this parameter the VDU cannot load it's workstation program.
This short video sequence shows how to enter the default setting - 0815. This specifies a communication speed of 9600 baud.
You MUST enter this sequence as soon as you turn the VDU on from the keyboard. If you make a mistake you have to switch off, and back on again. Also, you have to use the numeric keypad and the CR key as shown. Don't try this user the numbers above the main keyboard area, or the large CR key as it won't work and you will have to start again.
I seem to remember that parameters 0812 were used for 1200 baud (we used to connect DAP4s directly to modems for customer remote support purposes).
This would mean that:
However, check the ALME settings for the channel in question. It may be sensible to start at 9600 baud at both ends, and then experiment from there.
If the workstation starts to load you will see L1 and L2 flashing alternatively and then after a few seconds L4 will illuminate. At this point you should hear the HT voltage that powers the VDU tube engage; a slight static electricity type sound. You should see "CR" appear on the display within 30 seconds. If not, check the brightness and contrast controls - located in the PSU near the mains power switch - back top right corner.
I seem to remember that parameters 0812 were used for 1200 baud (we used to connect DAP4s directly to modems for customer remote support purposes).
This would mean that:
- 0816 - 19.2K baud
- 0815 - 9600 baud
- 0814 - 4800 baud
- 0813 - 2400 baud
- 0812 - 1200 baud
However, check the ALME settings for the channel in question. It may be sensible to start at 9600 baud at both ends, and then experiment from there.
If the workstation starts to load you will see L1 and L2 flashing alternatively and then after a few seconds L4 will illuminate. At this point you should hear the HT voltage that powers the VDU tube engage; a slight static electricity type sound. You should see "CR" appear on the display within 30 seconds. If not, check the brightness and contrast controls - located in the PSU near the mains power switch - back top right corner.