14 Dec
2020
14 Dec
'20
8:51 a.m.
On 12/14/20 6:28 AM, Paul Koning via cctalk wrote:
Back in the day (why is everything now "back in the day"?), I wrote the
firmware for a Fortune Systems text terminal. The requirement was for a
certain degree of NAPLPS/Videotex compatibility. Combining certain
characters was done via lookup in the character generator ROM, not by
combining them as graphical characters. I suspect that this was the
method used for a large number of terminals, such as the Telidon units.
--Chuck
Is it really
an overstrike? They look simply like different characters.
At least, I didn't (probably missed it) how they can be generated out of
the available ones...
I wondered too. General overstrike requires a bitmap display, or some sort of persistent
display. Paper is an example; a Tek 4010 would also handle overstrike since it uses a
storage tube. And PLATO terminals did overstrike just fine since they are bitmap displays
with per-pixel memory.