A guy on the German VzEkC forum measured the output of the graphics extension card to the 9pin D-sub connector on the back of the machine and found TTL level R-G-B, 50Hz VSync "with a negative pulse" and 15.6kHz HSync.

He describes that in order to use the bootable MS-DOS disk he had to rename the config.sys file so the driver disdeu.sys wouldn't be loaded as that would cause the display to scroll and blank.

Could it be that the graphics extension is only meant to serve the monitor on the digital output and disdeu.sys is a monitor switcher?

There's a spurious "w" character generated on reset of the P30 ... dunno where that's from. I hope the firmware dumps are OK.

Last edited by rfka01; 02/25/18 05:00 PM.

NCR DMV- DEC Rainbow- Siemens PCD- ITT 3030-Oly People- Acorn A5000- Olivetti M20