exxos's Atari, Amiga & retro forum

I own an Atari 1040SFT in german language and I want to move it to the Spanish (or English) TOS v1.04 language

After browsing the Exxos webshop it seems that there's no kit to do this, because my actual TOS is two-chips only instead of six. I'm wrong or there's a way to install the upgrade that I want ?

Here are two pictures that maybe will help to find a solution:


Thank you!

DUALTOS https://www.exxosforum.co.uk/atari/store2/#0131

Or "downgrade" to 6 chip TOS. https://www.exxosforum.co.uk/atari/store2/#0119

exxos wrote: 03 Jun 2021 19:46 DUALTOS https://www.exxosforum.co.uk/atari/store2/#0131

Or "downgrade" to 6 chip TOS. https://www.exxosforum.co.uk/atari/store2/#0119

In case that I downgrade to the 6 chips version, do I need to solder something else than the sockets for the TOS chips? It is necessary some additional modification on the board or just add the 4 new chips?

There's no problem with the extra power DC consumption when passing from 2 to 6 chips ?

Thank you

Papalapa wrote: 04 Jun 2021 11:33

exxos wrote: 03 Jun 2021 19:46 DUALTOS https://www.exxosforum.co.uk/atari/store2/#0131

Or "downgrade" to 6 chip TOS. https://www.exxosforum.co.uk/atari/store2/#0119

In case that I downgrade to the 6 chips version, do I need to solder something else than the sockets for the TOS chips? It is necessary some additional modification on the board or just add the 4 new chips?

There's no problem with the extra power DC consumption when passing from 2 to 6 chips ?

Thank you

If you 'downgrade' to 6 chips, the machine will run just fine with no power problems. Aside from soldering in the sockets, there are pads near the ROMs marked 1M or 256K, or very similar.

For 2 ROM sets these are set to 1M, so you will need to desolder the pads and solder the 256K pads instead. You may need to also add a 74 series logic chip, I think an LS11, but if you can post a clear picture of the whole motherboard then we can have a look to see if you need it or not.

rubber_jonnie wrote: 04 Jun 2021 11:44 If you 'downgrade' to 6 chips, the machine will run just fine with no power problems. Aside from soldering in the sockets, there are pads near the ROMs marked 1M or 256K, or very similar.

For 2 ROM sets these are set to 1M, so you will need to desolder the pads and solder the 256K pads instead. You may need to also add a 74 series logic chip, I think an LS11, but if you can post a clear picture of the whole motherboard then we can have a look to see if you need it or not.

Many thanks for your support, on my first post there are the picture area of the PCB where the TOS is installed and the board revision. Anyway, here's the picture of the whole PCB (hope this image resolution will be enough):

Its a bit fuzzy, but I think you're ok, though if you could get a clear shot of the IC immediately below the power connector and to the right of the row of resistors, I think that's it, but I'd like to check.

rubber_jonnie wrote: 04 Jun 2021 12:01 Its a bit fuzzy, but I think you're ok, though if you could get a clear shot of the IC immediately below the power connector and to the right of the row of resistors, I think that's it, but I'd like to check.

Here's it. The IC is the SN74LS11N

Pretty sure you're good to go then.

exxos wrote: 03 Jun 2021 19:46 DUALTOS https://www.exxosforum.co.uk/atari/store2/#0131

Or "downgrade" to 6 chip TOS. https://www.exxosforum.co.uk/atari/store2/#0119

Many thanks for the information and also to @rubber_jonnie for the clarifications.

This morning already ordered the Spanish 6 chip set.

Have a nice day :D

You're welcome.