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Member Since 23 May 2011
OFFLINE Last Active Nov 15 2018 11:38 AM

#4133510 SIO2BT

Posted by TheMontezuma on Sun Oct 14, 2018 3:49 PM

I have some updates about the SIO2BT app.


The new version 3.00 of the app was just released:

- it has improvements related to the file selection (a filter to narrow down the number of displayed matching files, useful when dealing with huge number of files)

- it does not have a Bluetooth MAC address database anymore and allows connections to any BT SPP devices (like HC-06) with names starting with "SIO2BT" or "ATARI"

- the app source code is released under GPL license: https://github.com/TheMontezuma/SIO2BT

- the apk file is also uploaded to the Github: https://github.com/T...3.00/Sio2Bt.apk


I would like to thank you guys again for your support over the last years.

Four years ago SIO2BT was submitted to the ABBUC contest and won the first price :)

And now I decided to release the source code and to remove MAC address database protection.


To be honest my decision was accelerated by a new Google security policy.

Starting 1 Nov 2018, there will be no updates allowed to the apps targeting older smartphones.

This means, the version 3.00 will probably be the last version available via Google Play.


I tested it on various Android devices:

- LG with Android 2.3

- Huawei with Android 4.0

- Nexus 5 with Android 6.0.1

- Pixel XL with Android 9

and I hope it will continue to work properly on your Android phones/tablets.


I also recommend a great Android port of the AspeQt (with Bluetooth support) from Greblus:



and the PC RespeQt software:



Have fun!



Although you can use now any BT transceiver with the SIO2BT app, I still have a limited number of devices in the 3D printed cases.

#4057253 45+ Years to Sunnyvale, California: a pilgrim's journey...

Posted by TheMontezuma on Tue Jun 26, 2018 6:07 AM

And one more:


1265 Borregas Ave.jpg


1265 Borregas Ave


It is sad to see this nice office building staying empty.

If you look closer, you will see one of many new Google's fancy glass offices (in the background).

It seems that 30 years old buildlings do not match modern standards any more and are too small for the giants...

#4057037 45+ Years to Sunnyvale, California: a pilgrim's journey...

Posted by TheMontezuma on Mon Jun 25, 2018 7:11 PM

Dreams come sometimes true :)


1196 Borregas Ave.jpg


1196 Borregas Ave today

#4052904 Sophia rev.C - DVI board

Posted by TheMontezuma on Wed Jun 20, 2018 1:41 AM

New latency measurements are available for SOPHIA-DVI:




BigBen's setup allows to messure the difference in the latency between 2 monitors.

We have used FUNAI-A1506 TV (popular in Germany) as a reference device (connected to Atari's analog video output), because we didn't have any CRT at hand.

We compared the latency with Acer S200HLBbd PC Monitor (1600x900) connected via DVI to SOPHIA.

Acer has 5ms latency according to the technical specification. FUNAI has exactly the same latency (5ms) compared to CRT monitors (messured before).


The results of the measurement show exactly the same timing, which means that SOPHIA-DVI does not introduce any additional delay in video processing. It not only provides sharpest picture ever, but it is also damn fast :)



#4037539 SIO2BT

Posted by TheMontezuma on Wed May 30, 2018 2:19 AM

I don't know yet.

My concern was not to break support for old Android devices.


Some apps at Google Play are branched at one point of time (for example: MyFRITZ!App and MyFRITZ!App 2)

The older version is frozen and the owners of the older devices can still install and use that version,

while a new (re-written) app (with a new name) is added to Google Play, which targets the latest API.


I hope to be ready with all new features (including "internet modem") until November :)

#4037512 SIO2BT

Posted by TheMontezuma on Wed May 30, 2018 12:12 AM

Attached is the apk file:

Attached File  Sio2Bt_App_ver_2.85.zip   72.62KB   30 downloads

#4037129 SIO2BT

Posted by TheMontezuma on Tue May 29, 2018 2:23 PM

After a long break in development I released one convienient feature.


The background story:

My my favourite website with the collection of the Atari games offers a link "Download All".

If you unzip the content, the games are copied to directories named after the first letter of game names.

Until now, after mounting a game in the SIO2BT app, you couldn't easily just mount the next one,

because the file list view was always showing the first items in the directory at the top of the screen.

For directories with many games (as this is the case with Homesoft collection) it meant scrolling, scrolling, scrolling...

Now comes the change, the file list view will automatically scroll to the previously mounted game,

so you can easily mount the next one :)


You will find the vers.2.85 of the SIO2BT app as always at Google Play.


I'm also going to add handling of the favourite games and a search function in the next weeks.



Google has "motivated" me to revisit the app, because of the deadline they set for the existing apps at Google Play.

Due to security reasons, Google wants all apps to target the current Android API version.

I will be able to provide updates (via Google Play) to the SIO2BT app only until November 2018.

This is because my app is targeting a very old Android API (API Level 7 = Android 2.1).

After this date, the updates of the SIO2BT app will only be possible through the *.apk files (which is not that bad, but less convienient).









#4030156 Sophia rev.C - DVI board

Posted by TheMontezuma on Fri May 18, 2018 3:36 PM

One more try:

A monitor with a native resolution: 1600 x 900


In reality, the picture is much more sharper than on the photo :)

#4021164 Sophia rev.C - DVI board

Posted by TheMontezuma on Fri May 4, 2018 12:10 PM


Is it a sparkling effect on random pixels that you see? I had this problem with a pi zero connected to my benq computer monitor. I fixed it by using a very thick gauge HDMI cable. The cheap thin HDMI cable was really bad. A medium gauge cable was improved but still sparkled. Then I used one of the really thick cables that doesn't bend well and the pi zero looks perfect with that. I can't find the model or brand name of it right now.


Thanks for the hint. I gave it a try and purchased another DVI-HDMI cable.

This time I went to the computer shop and asked for a cable to connect a computer to the 4K TV.

And the weird pixels are gone :)  So I'm a little bit dissapointed about the "Amazon Basics" cable quality, which was not good enough for 4K ...



4K game on a 4K TV:


4k game on 4k tv.jpg

#4014257 U1MB plugin development

Posted by TheMontezuma on Tue Apr 24, 2018 11:50 AM

The plugin I succesfully tested in Altirra didn't work with the real hardware :(


The funny thing is that as long as the PBI BIOS is active (or unlocked according to the documentation) you can not execute the following code:

    lda #$00
    sta $D500

Or actually you can, but it does not do what you want :(


The trick Jon has invented was to copy some parts of the plugin code to RAM, lock the U1MB BIOS, then write 0 to $D500 and jump to the OS :)

#4014231 I do not have to play Robbo anymore

Posted by TheMontezuma on Tue Apr 24, 2018 11:12 AM

My bot watched it and he told me he is impressed. He said he is going play a few rounds of Robbo, too ;)

#4014076 I do not have to play Robbo anymore

Posted by TheMontezuma on Tue Apr 24, 2018 7:19 AM

And I do not have to watch your Robbo game play anymore, because I have a bot, which is watching it for me :P

#4013549 U1MB plugin development

Posted by TheMontezuma on Mon Apr 23, 2018 12:24 PM


Thank you for help :)

I have checked it out and I'm very happy with the results (I checked Atarimax 8mb, SIC and Megacart 4MB images)

In case somebody would like to try it out:

Attached File  MulticartsMenu.zip   214.91KB   30 downloads

The file contains the source code of the modified defaultplugin, the plugin as a binary and the complete U1MB rom (512kB) with the updated plugin. Everything based on the version 1.25 of the U1MB firmware.




It would be great if you could merge it into the upcoming 2.00 delivery :)

#4013278 Thanks and Cheers to A8 coders & creators

Posted by TheMontezuma on Mon Apr 23, 2018 2:34 AM


Please don't get me wrong but it looks like a mutual admiration society.

I understand that you had good intensions but you will always miss somebody this way.

Since you wanted to appreaciate all creators, it would be better not to name any person at all, rather than to forget somebody and make him sad.

It is just my opinion.


#4013275 U1MB plugin development

Posted by TheMontezuma on Mon Apr 23, 2018 2:22 AM

Since there is no dedicated thread about the U1MB plugin development, I started a new one.


There is a nice introduction into this topic here:



I understood that the plugin binary compatibility between the versions 1.25 and 2.00 of the U1MB firmware will be broken.

Unfortunately Jon was continuously updating the documentation on his web page, so the current version does not match the (still official) 1.25 release anymore. The 2.00RC firmware distributed to volontiers was only a binary.

I understand that version 2.00 will be released soon (together with updated docs and example plugin source code).


Until then the only way to play around with plugin development is to use version 1.25.

And so I did:


I have modified the HardwareSetup section:

    .local HardwareSetup
    lda #$00
    sta $D500

compiled it and tested in Altirra only (since I already have the 2.00RC in my real U1MB).


It works as supposed. On every reset the memory bank containing a menu on the multicarts: Atarimax 1mb / 8mb, SIC, etc. is selected.

Since those carts do not have a reset button, you would need to power off the Atari to start a new game.

Now you just press RESET and voila the cart menu is displayed :)


In the next setp I wanted to make it configurable: to enable/disable this feature over U1MB menu.

I looked at the source code and I'm confused:

    .local StereoToggle
@    dta Item[0] (1,CovoxToggle,Title,ItemType.OnOff,StereoPokey,Help,Cfg.Aux,$01)
    .byte 'Stereo Pokey',0
    .byte 'Enable/disable stereo audio',0
    .local CovoxToggle
@    dta Item[0] (1,Device3Toggle,Title,ItemType.OnOff,CovoxFlag,Help,Cfg.Aux,$02)
    .byte 'Covox',0
    .byte 'Enable/disable Covox',0

Menu item for Stereo uses CovoxToggle and menu item for Covox uses Device3Toggle ?