IBM 5110 Display Card
Here is an example of the Display Card from the IBM 5110. It has a set of jumpers on the left side edge that are used to decide the default character set.
Internal CRT Display Notes
The IBM 5100/5110 include a 5″ integrated CRT. As with most CRTs, the internal display has several adjustment knobs along the top of the circuit board. Even with just age, these settings may need adjusting to maintain a clear and stable display image.
It is a self-contained unit and per the IBM 5100 MIM documentation, the 10-pins on the controller board are as follows:
External Display
On the back side of the IBM 5100/5110, there is a BNC-connector for video output. When the IBM 5100 was made available in mid-1970s, BNC was used in high resolution security monitors or laboratory equipment, and not normally available to non-business owners. RCA was one of the companies that would provide these kinds of “monitor” televisions, typically between 9 to 14 inch size, and they did offer higher resolution than most standard color televisions of that time.
BNC still remains a popular type of connector even today, since it can maintain the signal over relatively far distances. And BNC can be easily adapted to “RCA” (or S-Video) style with very inexpensive adapters.
Below are examples of JVC CRT monitors from the 1990s. While these may still work with the IBM 5100/5110, they may require setting adjustments (some of which are located only inside) to get the image centered, stable (non-scrolling), and clear.
As working CRTs becomes more difficult to find, using a modern LCD monitor is also still an option. You can also find BNC to VGA/HDMI adapters, which altogether will also use less power than the old CRTs.