exxos's Atari, Amiga & retro forum

Hi everyone,

I've posted a couple of times so far, but not much about my projects. I'm originally an MSX guy and jumped straight from that into a 386DX40 in the early 90s. I ended up missing all the 16-bit computers, which were rare and expensive at the time in Brazil. However, my dream back then was to own an Amiga. As I've started getting into retrocomputing, I've come across the Ataris and developed an interest in them. Somehow, I've ended up with _four_ of them in my collection.

Whereas I'll eventually post about my MSX and Amiga projects (they're ongoing), today I want to share my current project: pimping out the German 1040STE I've acquired a few years back. The first big goal is to install the TwiSTEr expansion I've bought a year and a half ago but haven't had time to install.

The first step is, of course, to replace the old 1.06 ROMs with newer 2.06 chips, in the original German that befits the machine. After a couple of visits to the well-equipped Makerspace I have at work figuring out the equipment and desoldering the original ROMs to install sockets, the board powered right up with the original ROMs. Out of excitement for not having destroyed my PCB I quickly replaced them with the 2.06 ROMs Matthias sent together with the TwiSTEr. Unfortunately, the STE would power up, show bombs and reset continuously. That's when I remembered I hadn't moved the jumper resistors. Once I did so, I was greeted with this nice boot up screen right off the bat:
My excitement didn't last very long, unfortunately, as after the wait completed I was greeted by four bombs:
Matthias did say he hadn't tested the EEPROMs yet, so that will be my first course of action, which I'll try tonight.

4 bombs is normal for an STE with TOS 2.06 and no floppy drive connected.

Hook up a floppy drive or Gotek and see where that takes you 😁

Don't forget you probably need to flip the FDD cable for a Gotek as pin 1 is down at the end next to the power connector.

rubber_jonnie wrote: 24 Feb 2025 12:32 4 bombs is normal for an STE with TOS 2.06 and no floppy drive connected.

Hook up a floppy drive or Gotek and see where that takes you 😁

Ah, that's excellent news! I assumed it worked okay without it because the original 1.x TOS booted to the desktop just fine. Ok, will run back to the Makerspace later to try it out.

b_squared wrote: 24 Feb 2025 12:49

rubber_jonnie wrote: 24 Feb 2025 12:32 4 bombs is normal for an STE with TOS 2.06 and no floppy drive connected.

Hook up a floppy drive or Gotek and see where that takes you 😁

Ah, that's excellent news! I assumed it worked okay without it because the original 1.x TOS booted to the desktop just fine. Ok, will run back to the Makerspace later to try it out.

No worries, it catches a few people out, be good to hear what the results are with the FDD connected.

And there we go, plugging in the floppy drive made TOS 2.06 happy:


Now onto the fixes required for the TwiSTEr expansion...

b_squared wrote: 24 Feb 2025 18:35 And there we go, plugging in the floppy drive made TOS 2.06 happy:

IMG_3678.jpeg

Now onto the fixes required for the TwiSTEr expansion...

Good stuff 😁

Further progress: the TwiSTEr is booting just fine after doing the minimum recommended fixes:


Haven't done extensive testing yet, ran out of time. I also went ahead and removed the modulator, hoping to reuse the space for the TwiSTEr's USB header or perhaps an internal Ubeswitch in the future. Will now probably partially reassemble the unit and bring it back to my desk to test all of the features and start thinking about how to bring out the switches.

So I set aside some time this morning to put the STE back together and I took it back to my desk. I now have a 4GB CF card connected to the IDE port of the TwiSTEr. Unfortunately this means I need to choose between having a floppy drive or use the internal IDE port, because the TwiSTEr has only one floppy power connector (it uses the original one for its own purposes). Right now I have a drive image I've put together with Geneva and TeraDesk, plus some other goodies:


This is all with the '020. For whatever reason, using the 68000 is giving me bombs, sometimes even before the desktop comes up:


Will resume troubleshooting tomorrow, but first experiences are overall promising!

There is a power connector/pinheader on TwiSTer. On top of all the jumpers you have it marked with PWR and + and -. You can use dupont connectors with wires to get 5V/GND to your CF adapter.

b_squared wrote: 10 Mar 2025 14:39 So I set aside some time this morning to put the STE back together and I took it back to my desk. I now have a 4GB CF card connected to the IDE port of the TwiSTEr. Unfortunately this means I need to choose between having a floppy drive or use the internal IDE port, because the TwiSTEr has only one floppy power connector (it uses the original one for its own purposes). Right now I have a drive image I've put together with Geneva and TeraDesk, plus some other goodies:


IMG_3701.jpeg


This is all with the '020. For whatever reason, using the 68000 is giving me bombs, sometimes even before the desktop comes up:


IMG_3700.jpeg


Will resume troubleshooting tomorrow, but first experiences are overall promising!

Get or make a power lead splitter. Pretty easily available on eBay.