Televideo 925 character rom dump

Al Kossow aek at bitsavers.org
Thu Apr 25 10:55:26 CDT 2019




> The 924 should be the same as a 955 keyboard.  There seemed to be two compatible types of the keyboard - an older
> thicker keyboard (shipped the TS-803 et al, and looks like an enhanced 925/950 keyboard), and a newer thinner profile
> keyboard used on later terminals.
> 
> From what I've figured out, the 955 uses a 6-pin connector at 9600 baud with both Tx and Rx used, and a reset line and
> +12V power. The 925/950 use a 4-pin connector, replaces the Tx to keyboard line with a speaker connection, drops the
> reset line, and runs at 1200 baud as compared to the 955 keyboard.  The keyboard should be the same between the 905,
> 955, 970, TS-803, and some others with the possible difference of some legends on keycaps.  The TS-802, 800A, 925, and
> 950 use the same keyboard +/- some legends. 
> 
> Later terminals like the 965 use a 4-pin connector with a different pinout, and +5V supply instead of +12V, but still at
> 9600 baud with the same codes as the 970/etc.
>


Alex Riedlmayer has been doing a lot of work on simulating Televideo terminals in MAME.
There should be a lot of (if cryptic) info on the logic boards and the high-level or uP simulated
keyboards in the sources.




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