It has a mechanical calculator? Wouldn't the radar require an analogue computer anyway?
Can you perhaps tell us a bit about how Shilka tracks a target and does the target calculations?
During development, the main aim was the creation of a robust and cheap system, that each (!!!) WarPact regiment could have equipped with 4 of these vehicles.
The small, low power, pencil beamed 1RL33 (Gun Dish) is providing only the target coordinates, and speed.
The 180kg (!!!) SRP (mechanical fire solution calculator) has ~60 electrical motors, and ~110 axis with associated gears.
1, Vx unit
2, Vh unit
3, Beta-u unit with K1*
4, X unit
7, H unit*
8, Fi unit*
9, Tu unit*
10 BP control unit*
11, Y unit
13, Vy unit
* visible in SAMSIMIt takes the whole space before the commander.
From the X,Y,H and Vx, Vy, Vh coordinates provided by the 1RL33 (Gun Dish) radar, it calculates the Tu time, when the bullet would hit the target. From this, it calculates Fi (elevation plus bullet drop angle) and Beta-u (azimuth lead angle).
The gyroscope will provide K1 data in case the vehicle moves, to stabilize the firing solution.