First, you should always have a look about the current version of your device and so if your really need an update.
If you power on the A190-4 this is show at first on the display. F.e. '105' for version V1.05.

V1.05:
the changes:

- CV2 that had an automatic slide/portamento on - now we switch this off, when you assign velocity to it/also when load from non volatile memory.

In all other assigns it has a default slide as till V1.04 - but this could now be changed with CC# 37 ( portamento lsb) from external via midi in, as with the normal portamento time for CV1. this value is only temp. and could not be stored ...

- The ClockPolarity Menu now has 4 changeable values  ( till 1.04    only Pos<->nEg)  now  4  Pos<->nEg<->Pos<->nEg  - where the second 'Pos<->nEg' combination now will change the reset Pol - 'Pos<->nEg' will furthermore only change clock.

This seems a little bit unhandy and also you cannot see the ResetPol direct in the display - but you can see it direct with the reset led, as it changes.

This was the only method to integrate this feature fully into the firmware - also with store possibility - without to get a memory overrun .

- also some little fixes - f.e. midiclock thru only worked after a start command , but not after a continue command. Now fixed !

V1.04
=====

- Switch off  Midithru for USB - otherwise in some configurations (Logic Pro on MAc) midi feedback loop
- Miditrhu (legacy midi)now also for realtime events: Start,Stop,Cont,Clock
- logarithm. charact. for LFO
- delete distortion/artefacts effect, when changing AMP/mod of LFO on it's waveform

V1.03
======

improved clock sync in some configurations/DAW's

The upgrade procedure is in principle the same as for the DarkTime.

http://www.doepfer.de/update/en/index.html

There is also a section for Mac OS …

So, if you want to make the update with Mac, a customer told us, that this app, we used here for Mac to update, maybe doesn’t work any longer. Cause it is a 32Bit program and on newer Mac you only can use 64 bit ones.

Cause this program is not made by us, we cannot offer any update on 64 bit here.

So, in this case you had to find (someone with) a Win PC for the update

 
Please read all instructions carefully!

Sure the DarkTime and the electronics of the two devices looks different. but for the update it's nearly identical.

You also have to remove a certain  jumper for both device for the update and reinstall after that for normal mode.

The jumper for the update is on a different place.

Have a look on the two pictures you can also download from this site:

First:   - Look where the jumper(at this time already installed)  is ( right upper corner - if the module is located with its electronic side to you. )
A190_4_jumper_normal_mode.jpg.   See label JP6

Second: Remove the Jumper that is next to the text JP6  - look at the picture. A190_4_jumper_update_mode.jpg
When you now power the module also the Gate led should flash - now you're in update mode and you can all the things described in the DarkTime update manual for updating.

(Note: if you do the flashing of the program code you see the success, if then the gate led flashes slower than before ...)

The a190_4_2550_V1.05_fw_c_161024.Hex file which you can download in a zipped version, is the code file you need for the update instead of the one for the DarkTime described in the manual. 

If you then use the program PDFSUSB.exe  ( for windows only) Please read the Instructions in http://www.doepfer.de/update/shared/files/DarkTime%20OS%20Update%20WinXP%20english.pdf

Carefully  - special page 12

"ATTENTION:  Only click on these two buttons – never click on functions like ‘Read Device’,’Erase device’ ..... if you do this by mistake don’t go on in the update process and don’t click on "Program Device", but better leave the program and restart it.

Otherwise there is a good change that you 'brick' your device and have to send it to support, which is then not free of charge ! Also is no case of warranty !