New profile - Texas Instruments Professional Computer

[burbon04]

The Texas Instruments Professional Computer (TIPC) featured an 8-color (RGB, no intensity bit) video card with 720x300 pixels resolution, 18 MHz pixel clock, sold with a proprietary monitor. The video port is similar to CGA and can be connected almost like IBM PC CGA/EGA, just without the intensity pin. However as the VSYNC signal is inverted, I needed to add an 74HC14 to get a stable video output.

The wiring is like this:

• RGB2HDMI +5V PIN -> 74HC14 PIN 14
• RGB2HDMI GND -> 74HC14 PIN 7 and TIPC DE9 PIN 2
• RGB2HDMI BLUE3 -> TIPC DE9 PIN 5
• RGB2HDMI GREEN3 -> TIPC DE9 PIN 4
• RGB2HDMI RED3 -> TIPC DE9 PIN 3
• RGB2HDMI HSYNC -> TIPC DE9 PIN 8
• RGB2HDMI VSYNC -> 74HC14 PIN 2
• TIPC DE9 PIN 9 -> 74HC14 PIN 1

Two new profiles need to be added for 50Hz and 60Hz setups (determined by a mainboard jumper), see attached. Both tested to work with the TIPC I have, using "Texas_Instruments/Professional_Computer" for the profile location.

Somehow the RGB2HDMI even manages to get a video without the VSYNC signal corrected, but it's not stable and tends to blink at times?
If VSYNC inversion can be done in software the 74HC14 could be omitted.

TIPC_50Hz.txt
TIPC_60Hz.txt

[burbon04]

update - actually the automatic SYNC_BIT_VSYNC_INVERTED works far better than expected, I get a stable signal now even without the 74HC14. Might have been the breadboard cabling. However, the profile needs to be adjusted for best results.
Cabling in that case exactly like CGA, without the intensity line.

I might suggest adding both variants, just in case?

TIPC_50Hz_direct.txt
TIPC_60Hz_direct.txt

Absolutely great open source project, incredibly useful for retro hardware