Search found 97 matches

by troed
Thu Oct 05, 2017 9:47 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 45
Views: 2803

Re: Boosting STFM: 16MHz bus, 64MHz Shifter

ah ok, thought you had a scope (my bad sorry!) I thought so too until I checked what was in the LA box I purchased a while ago today ;) I would make sure you have some 33R in series with clock inputs and outputs. The LA does not show the "real picture" a lot of the time. Signals could be glitching ...
by troed
Thu Oct 05, 2017 9:39 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 45
Views: 2803

Re: Boosting STFM: 16MHz bus, 64MHz Shifter

You also need to post scope images to see the ringing on the signals and adjust series resistors accordingly. Yeah apparently I need an oscilloscope extension for my LA and it's only available for the previous hw version :( Or something. I had really hoped not having to buy a separate oscilloscope ...
by troed
Thu Oct 05, 2017 7:45 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 45
Views: 2803

Re: Boosting STFM: 16MHz bus, 64MHz Shifter

Here's a capture of the 16MHz (from MMU), 8MHz (from MMU) and 4MHz (divided by the 74LS74 from the 8MHz) taken at the maximum speed of my LA. The relationship between the clocks is stable between captures at that speed. la_16_8_4_400mhz.png edit: Annotated. I'd say the 8MHz clock (MMU original 4MHz)...
by troed
Thu Oct 05, 2017 5:05 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 45
Views: 2803

Boosting STFM: 16MHz bus, 64MHz Shifter

edit: A long prosaic writeup of all the steps can be found here: https://blog.troed.se/projects/atari-st-new-video-modes/ Since a few months back I've slowly been modifying one of my 1040 STFMs with the "Stefan Nitschke 16MHz mod". I got the inspiration from an Atari-Forum thread by exxos where he s...
by troed
Mon Oct 02, 2017 1:07 pm
Forum: EVERYTHING ELSE
Topic: Boosting the Mega ST motherboard
Replies: 11
Views: 718

Re: Boosting the Mega ST motherboard

I had to select a MMU to get it going. And then I would also get a picture and desktop in High-res, but with "Jailbars" Jailbars is due to a slight clock desync between Shifter and MMU. You could try inserting some component that would delay the clock a bit. (As exxos mentioned I'm slowly doing thi...
by troed
Sat Sep 30, 2017 3:02 pm
Forum: ROM UPGRADES
Topic: TOS104 / TOS102 MEGA ST
Replies: 2
Views: 249

Re: TOS104 / TOS102 MEGA ST

Going by myself and the one other person I recently suggested this kit to, it's very common to lack the 74LS11. It's a very cheap chip, unless you need to find a local supplier and pay postage for a single one ;) Maybe you could supply them with the kit?

/Troed
by troed
Wed Aug 30, 2017 6:28 pm
Forum: PSU (power supplies)
Topic: Discharging capacitors, PSU-testing with dummy loads
Replies: 21
Views: 1394

Re: Discharging capacitors, PSU-testing with dummy loads

Also, the PSU might not start up as it should if you only connect the 12V test resistor. You need to load the 5V rail as well with the other one.

(I don't recall which PSU I did when I realized this, either Falcon or MSTE I think)