STE video chip

[exxos]

STE_1712_FIX.jpg

To bring this investigation to an end now, I have now done a page of it on my website.

https://exxosforum.co.uk/atari/last/1712fix/index.htm

Boards available in the store.

https://www.exxosforum.co.uk/atari/store2/#0288

Unfortunately due to the amount of revisions of boards I had to do and related costs and low quantity, the price ended up rather high. Though I don't think many people would be really wanting these boards anyway. I don't know how widespread all the problems are. But indeed it fixes problems on my machines, so they may be useful to others in the future as well. I don't plan on spending any more time on researching this problem now anyway.

Also my previous video series on RAM related issues with the 1712 are also documented on my youtube video series.

https://www.youtube.com/@exxosuk/search ... MB%20fault

[antorsae]

Hello I have just bought a Mega STE which has the 1712 shifter.
Some demos with full screen effects exhibit weird behavior somehow similar to the ones described here.
Would the board work on a Mega STE? If not, it is possible to buy the C300588 shifter anywhere?
Thank you!

[exxos]

Hello I have just bought a Mega STE which has the 1712 shifter.
Some demos with full screen effects exhibit weird behavior somehow similar to the ones described here.
Would the board work on a Mega STE? If not, it is possible to buy the C300588 shifter anywhere?

The work was all done on a STE not MSTE. It's a totally different machine. Demos are unlikely to be stable with the cache on ? Or may not even be MSTE compatible?

[antorsae]

Hello, most/all of the demos work. I believe the MSTE has cache disabled by default and runs @ 8 Mhz by default. If I understand correctly you are adding a (variable?) delay to the 16 Mhz clock. If I cannot procure an alternative shifter I'll be interested in trying your solution.