exxos's Atari, Amiga & retro forum

Hi Guys

I am interested in the 4 MB RAM upgrade for my Atari 1040STF with Rainbow TOS 1.04.
Sadly, I have the "Silly" mother board:


The original 1 MB RAM is not socketed, it is soldered directly to the lower part of the MoBo in the pic (towards the front of the machine).
Both the shifter and the MMU are socketed.

So, would the assembled full kit work for me? If so, what would be the cost (including S&H to Rock Hill, SC, USA 29730)?

Thank you!

Same board is shown on the install page towards the bottom https://www.exxosforum.co.uk/atari/last/4MBMMU/index.htm

It's this kit https://www.exxosforum.co.uk/atari/store2/#0035

You need to add the item to your basket and select your country from the checkout page for postage costs.

So, you say kit #0035 is all I need.

The page states that cables and shifter board need to be purchased separately. Is that so? Or are the cables and shifter board still included with kit 0035??

ppyo wrote: 28 Dec 2021 03:33 So, you say kit #0035 is all I need.

The page states that cables and shifter board need to be purchased separately. Is that so? Or are the cables and shifter board still included with kit 0035??

You need the other bits as the store mentions as well.

Just installed one of these in a "silly" style motherboard just now and it works lovely! Trimmed the pins per the guide and it works wonderfully!

Thanks!

coonsgm wrote: 29 Dec 2021 20:37 Just installed one of these in a "silly" style motherboard just now and it works lovely! Trimmed the pins per the guide and it works wonderfully!

Thanks!

:bravo:

So I just got the 4Mb RAM upgrade in the mail. Now to prepare installation. I have the 1040ST with silly motherboard (pic in original post) and my question is which resistors I need to cut out and connect to 5v to deactivate the onboard RAM? My soldering skills are nonexistent (for now I will keep original RAM, but the idea at some point is to remove it). Also, I assume the pin trimming still needs to be done?

https://www.exxosforum.co.uk/atari/last/4MBMMU/index.htm

Scroll down to FITTING TO "SILLY STYLE" MOTHERBOARDS SUCH AS C070523

coonsgm wrote: 29 Dec 2021 20:37 Just installed one of these in a "silly" style motherboard just now and it works lovely! Trimmed the pins per the guide and it works wonderfully!

Thanks!

Hi!

Could you please tell me which resistors to lift for the silly MB? The image in exxos forum is kinda blurry. I can see that are to the left side of the MMU, but I like to know exactly which ones.

Thank you in advance!

Just lift the right hand side of the 68R resistors ( next to MMU ) and tie them to 5v.