A new old bug in the printer ROM?

[Christoph Giesselink]

(01-18-2023 07:24 AM)ThomasF Wrote:  Out of curiosity, how does it achieve this? Is this using the new 82143-mode?
I guess that the HP82240B.exe also could be used with a serial port and RedEye hardware and a real calculator.

Yes, It's a complete new mode inside the HP82240B.exe. It was a general decision somewhere in October last year to create a more a less exact font copy of the original printer to fully support all characters in the graphics window. This also allwed us, to build a special Unicode translation table for text mode. The external interface with UDP and serial port is untouched.

The major issue is, on this existing program base we have no return channel for the printer status. But a working printer status is an essential for a proper 82143 output. So V41 holds a copy of the printer status base on the data send to the printer simulation. Example, the printer sends an EOLL (0xE0) or an EOLR (0xE8). This is captured by V41 and sets the EOL and depended on the EOL type the TEO bit in the V41 copy of the printer status register. So on request of the printer ROM we get a correct printer status about EOL. Same I done with mode bits, an essential for lower case, double width and graphic (also known as special column) mode support.

Like with the IR-module (82242) and DM41X, V41 use Flag 15 and 16 to control the MAN/TRACE/NORM mode.