Problems to understand function of HT8950 for DBA Robot Project

[M.A.P]

Hi everyone,

I want to build the DBA Robot and found out that there are some issues with the schematics on the net and that the rotary switch still seems to be a magical component

So I was trying to get the function of the whole thing by reading the datasheet but this is puzzling me even more. On page 5 there is a table with the conditions of the inputs SW2, SW1 and SW0 and what the HT8950 does when they're pulled against ground. With a schematic using the 3P4T rotary switch I got the following states for each position of the switch:

Position1 - SW2=0; SW1=1; SW0=1 -> Function Normal
Position2 - 0;1;0 -> Function DN1
Position3 - 1;0;0 -> Function UP1
Position4 - 1;1;1 -> Function Controlled by TGU and TDG

In the schematic the pins 15-18 are unused. Normally they're used to switch through the modes but it seems that this can be done with the SW0-SW2 inputs, too. Except of vibrato mode. This is only toggle activated with pin 15 (that is unused in the schematic). So I think vibrato isn't used in the original Robot, right?
Also the effect in position 2 and position 3 could be increased by changing the logic levels to UP2 and DN2 (also UP3 and DN3).

In position 4 the HT8950 seems to switch through the modes like shown on the bottom of page 5.

It also says robot mode is active when the device is switched on. Does this change instantly to the effect that is choosen with the switch?

Can somebody verify my thinking?

Schematic http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/DBA/01-DBA_ROBOT_VERO.png
Datasheet http://www.sdiy.org/colbecklabs/spec_sheets/8950.pdf

[slacker]

I think your thinking is correct. I don't understand the purpose of position 4, the data sheets says that setting lets you step though the modes using switches on TGU and TDG but they aren't used in the layout so it seems strange to have that setting. Yes you could rewire the rotary switch to give you any of the settings on page 5 of the datasheet.
If I was going to build this I would do the switching like shown in this layout http://1.bp.blogspot.com/-QbkA3stWJAk/UZeKULtChlI/AAAAAAAAFmo/0Mg9UHdBPUc/s1600/Death+By+Audio+Robot+Mod.png that gives you robot and vibrato and all the steps.