Search found 468 matches

by troed
Mon Oct 16, 2017 4:50 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15538

Re: ST SHIFTER operation ?

While I think about it, has anyone noticed like the planes split apart on fast-moving objects on the screen? I have noticed this for a while actually.. Poorly done graphics libraries. Does not happen with proper demo scene code ;) I know of no such hardware issue. But I want to repeat that to be _d...
by troed
Sun Oct 15, 2017 9:48 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15538

Re: ST SHIFTER operation ?

1) Read Alien's description on how the Shifter works in Alive 11: http://alive.atari.org/alive11/oscan2b.php 2) Read everything Ijor has written on A-F on the subject - esp. since he's decapped a Shifter and looked at the actual logic :) (Several different threads over the years) If we want a re-imp...
by troed
Sun Oct 15, 2017 7:46 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

I just realized I don't need to guess about the difference between using the F161 16MHz clock for CPU (where memory only reached 100% speed) and using the MMU 16MHz clock (where memory access got to 200%) - I could use the LA to see what the difference is :P clocks_mmu_or_f161.png Surprising, actual...
by troed
Fri Oct 13, 2017 9:53 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

Alright, so here's the first slightly negative observation. The Shifter is indeed getting extremely stressed when in monochrome (where its internal pixel clock is the highest). I didn't see this until now, it takes a few minutes to appear and I've been mostly playing around in "low" res. Also, it's...
by troed
Fri Oct 13, 2017 8:12 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

Fantastic to finally see a proper speed result! Would also be nice to see stock medium res benchmarks at some point ;) I got 200% pretty much across all tests with GB3, but it wasn't a good test... Probably not far out from your second image anyway... BTW, it seems GEMbench cannot save screenshots ...
by troed
Fri Oct 13, 2017 7:49 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

So, back to this. Yes, the LA shows the 16MHz (first output of the 161) going hi at the same time as MMU 32MHz, however, the second and third outputs of the 161 are not synced to the rising but the falling edge of 16MHz. So, 8MHz never goes hi when 16 does but is always a half 16Mhz cycle behind. T...
by troed
Thu Oct 12, 2017 10:55 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

Alright, so here's the first slightly negative observation. The Shifter is indeed getting extremely stressed when in monochrome (where its internal pixel clock is the highest). I didn't see this until now, it takes a few minutes to appear and I've been mostly playing around in "low" res. Also, it's ...
by troed
Thu Oct 12, 2017 8:36 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

With ROM access at 179% display performance should be a lot higher. I'm actually assuming here the slowdown is due to 16 colours. Yeah, GEM graphics definitely takes more CPU in four bitplanes than two. I ran the same Gembench test in medium resolution (1280x200 :D :D :D) for a more proper comparis...
by troed
Thu Oct 12, 2017 12:09 pm
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

I never checked the sync of the 161, looks to clock on the rising edge and says rising in the pdf after a quick look, your LA seem to clock on the 32mhz HI, so would seem to be all correct I think , glad it proved it could work though! I can add that into the next booster logic now I know it works ...
by troed
Thu Oct 12, 2017 9:18 am
Forum: MEMBER BLOGS
Topic: Boosting STFM: 16MHz bus, 64MHz Shifter
Replies: 135
Views: 31586

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

Tests run with the latest GEMbench 6 - it's great to see programs not checking video mode ("low") but the fact that the resolution (640*200 - although there seems to be an off-by-one error in the detection) is good enough to run :D I'm still sure RAM should be 200% once everything has been tuned cor...

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