The Tto68k project started by a classic “phone call doodling” situation… but instead of drawing strange patterns I was fiddling alternately with one of Transputer TRAMs and a spare 68000 CPU I had laying on my desk.
At one point it dawned to me, that the 68000 classic 64pin DIL package perfectly fits in-between a TRAMs socket-pins 😲.
Obviously this discovery immediately had to go into a project which I called Tto68k – actually it is a spin-off from the STG[A]TW project which I recently did for the Atari Mega-ST.
So this is fully compatible and everything developed for that card (minus the VGA stuff, obviously).
Where space allows, the PCB offers certain features:
- 2 LEDs showing the Transputer status (running/error)
- An external Link, compatible with the STGATW and my CPU-relocator. Thus you can connect to another TRAM on that one.
- Dedicated 5V/GND pins to feed-in external power (if needed)
- Version 1.1 will have two “multi-purpose” pins (see below)
So while the features are pretty basic compared to the STGATW, it has one advantage: The 68000 socket is system-agnostic. And I don’t mean just the different ATARI ST models (520, 1040, Mega) but other systems, too. E.g. the AMIGA, the entry Macintosh line etc. As some of them have more advanced bus management than the ATARI, I saved two of the CPLDs pins as “multi-purpose” pins.
For example in the case of an AMIGA these could be used for the configuration chain (/CFGINn, /CFGOUTn).
While in the ATARI STs those will be used for TOS ROM decoding… or whatever comes to my/your mind.
All that said, this post is just an announcement for now.
Like mentioned, I’m working on a Version 1.1 which will be much more usable, especially for other systems than just the ATARI ST.