Search found 183 matches

by troed
Sun Mar 04, 2018 2:10 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 116
Views: 6480

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

... some 33 Ohm series resistors later. Getting there ;)


gal_series_resistors.jpg
gal_series_resistors.jpg (120.34 KiB) Viewed 247 times
by troed
Sat Mar 03, 2018 9:32 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 116
Views: 6480

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

Built this up on a test board and the GAL seems to work as indicated by the simulation, the relation between the clocks look ok. Not sure about the accuracy of the highest clocks though, my LA should capture them better than it seems to do. Also hooked it up to the STFM, and I get "unable to display...
by troed
Sat Mar 03, 2018 10:31 am
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 116
Views: 6480

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

So I'm still working on this mod. I want to be able to switch between doubleST (16MHz bus, new video modes), the original stefan-mod (16MHz bus) and pure stock. The crystals we have to play with are the new 64.000MHz and the old 32.08. Since this is not an exact multiple, to be fully compatible when...
by troed
Thu Mar 01, 2018 1:34 pm
Forum: HARDWARE DISCUSSIONS
Topic: WD1772-0202 - overheats at 16MHz
Replies: 13
Views: 606

Re: WD1772-0202 - overheats at 16MHz

Right, so the conclusion to this is that as I originally thought the WD1772-0202 as well as the VL1772 I tested with both did not work at 16MHz for longer than approx. the duration of formatting and writing to a disk. A WD1772-0202 tested to work at 16MHz (from exxos) has no issues, after having str...
by troed
Sat Feb 24, 2018 8:18 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 116
Views: 6480

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

Hmm. So I had to steal the recapped PSU from this machine to use in an STE I sold, and now I've just recapped the one I switched out and put back. ... and floppy isn't working. Everything else looks ok. Will have to figure this out - last time this happened it was due to not using good clocks from t...
by troed
Sat Feb 24, 2018 3:36 pm
Forum: HARDWARE ESSENTIALS
Topic: ubeswitch - video adapter.
Replies: 3
Views: 753

Re: ubeswitch - video adapter.

Yeah it's still on my todo ... :/ It is a bit tricky.

For demo developers, no driver is necessary. It's common to edit in high res, then disable VBL, switch to low - run the demo - switch back and enable VBL again. Works perfectly fine with the auto switching adapter :)
by troed
Tue Feb 20, 2018 11:54 am
Forum: HARDWARE DISCUSSIONS
Topic: 16BIT ROM CART THOUGHTS
Replies: 39
Views: 1719

Re: 16BIT ROM CART THOUGHTS

I have been thinking about the diagnostic cart where larger ROM's are used with a switch to select which version of the ROM to run (IE, ST, STE, MSTE etc). What bugged me is it used 2 chips. Arne's cart doesn't use two chips? Or is that very long DIL EPROM the functional equivalent of two? http://a...
by troed
Sun Feb 18, 2018 7:33 pm
Forum: TWEAKS & FIXES
Topic: Hissing and whistling in the STe audio output
Replies: 46
Views: 1445

Re: Hissing and whistling in the STe audio output

Interesting. .aiff with a completely silent (except for the whining noise) attached, it's from the 7an song I mentioned above, captured from my STE. Looking at the spectrum analysis (done in Audacity) there's definitely something interesting happening here. The two obvious peaks are harmonics, the s...
by troed
Sun Feb 18, 2018 6:14 pm
Forum: TWEAKS & FIXES
Topic: Hissing and whistling in the STe audio output
Replies: 46
Views: 1445

Re: Hissing and whistling in the STe audio output

How high frequencies can you hear? That's one of the key differences between those who hear this easily and those who don't, I think. It's a constant high pitched whine in one channel, in my experience. I'd wager around 15.5 or slightly higher (I know ...). Actually I have a wav I could analyze, sin...
by troed
Sun Feb 18, 2018 4:32 pm
Forum: TWEAKS & FIXES
Topic: Hissing and whistling in the STe audio output
Replies: 46
Views: 1445

Re: Hissing and whistling in the STe audio output

Yeah this is something I remember from my original STE way back then, and I also have it on my main STE now (not the same ;)). My memory tells me it's the left channel, but ... I have exxos' dac-cleanup but haven't had time to test it ... edit: So, original PSU when new as well as on my modern picoP...