Search found 468 matches

by troed
Mon Nov 06, 2017 11:51 am
Forum: HARDWARE DISCUSSIONS
Topic: Project: HDMI/DVI out for STFM
Replies: 526
Views: 67103

Re: Project: HDMI/DVI out for STFM

I found the disassembled TOS in the ST Internals book... but it's not OCRed so there's no easy way to search for specific addresses. Is there a better copy out there? I also found a copy of the TOS 2.06 source but it's probably quite different from 1.04, which is the version I have in the machine. ...
by troed
Wed Nov 01, 2017 9:34 am
Forum: HARDWARE DISCUSSIONS
Topic: Project: HDMI/DVI out for STFM
Replies: 526
Views: 67103

Re: Project: HDMI/DVI out for STFM

TOS boot process can be seen in the disassembly in ST Internals, if not in the actual TOS source available. It writes to video mode registers of course, but I'm not sure it reads. Maybe some HBL interrupts etc could be affected. In any case, booting from a diagnostic cartridge is often a good way to...
by troed
Thu Oct 26, 2017 9:25 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

Well, the calculations of what can be done are quite simple. It's best to think of them in bandwidth terms: MMU at 16MHz will latch&LOAD 80 words per scanline, 200 scanlines per VBL in low/medium. 80 words is 1280 individual bits. 200*1280 is the total bandwidth per VBL the MMU can handle. Now lets ...
by troed
Thu Oct 26, 2017 5:13 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

640x200 in 16 colours planer mode with double clocked shifter. 320x200 in 256 colours planer mode with double clocked shifter. Yes, this is what we can get. It's strictly limited by the speed of the MMU, how much data it can send per line. I do believe 256 color chunky is better than 8 bitplanes. I...
by troed
Tue Oct 24, 2017 10:26 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

... or you could use the extra bits to support 65536 colors similar to how the infamous dual shifter mod mentioned in another thread supports 32768 ;) True :) I don't think extending the colours more going to be that useful as we are still limited to 16 on screen anyway :) Well ... if you're redesi...
by troed
Thu Oct 19, 2017 10:39 pm
Forum: PSU (power supplies)
Topic: Arcing in Mega STe PSU
Replies: 27
Views: 6782

Re: Arcing in Mega STe PSU

I recapped an MSTE PSU not long ago, went back and looked at some photos I took. Sorry to say, I don't remember and can't see from the photos anything about a protective sheet between PSU and the metal casing.

/Troed
by troed
Wed Oct 18, 2017 5:37 pm
Forum: HARDWARE DISCUSSIONS
Topic: 32768 color dual Shifter ST mod - schematics lost?
Replies: 1
Views: 707

32768 color dual Shifter ST mod - schematics lost?

I've just read through the well known textfile describing "how" to add a 2nd Shifter to a regular ST and gain not only STE color palette compatibility but increasing it all the way to 32768 colors: http://atari4ever.free.fr/hardware/zip/32kcolor.zip Cool, I think, so I wanted to look into possibly d...
by troed
Tue Oct 17, 2017 7:42 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

Makes sense.. Question is, why is the shifter LOADing so much data in one go.. looks to be like 100 cycles, hard to tell from the image. I guess 16 pixels 4 planes is 4 words per 16 pixels, so would need 80 words for a scan line of 320px. ( 320 / 16 ) * 4 = 80 words... As there is a lot of LOAD pul...
by troed
Tue Oct 17, 2017 10:25 am
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

hmm... maybe Troed could take a LA of CS,LOAD,DE, 32mhz so we can see the relationship of all those signals. Adding two traces that Dio made a long time ago over at A-F, and I used as a basis for some of the thinking around the GLUE statemachine. shifter_160.png 50hz_video clock DE to load to scree...
by troed
Mon Oct 16, 2017 5:14 pm
Forum: HARDWARE DISCUSSIONS
Topic: ST SHIFTER operation ?
Replies: 94
Views: 15550

Re: ST SHIFTER operation ?

Thinking about it, more planes could actually be added.. I'm not sure what resolution and frame rate would end up like with the extra word been sent.. 1.jpg There seems to be plenty of room left in the register. We could actually use bit 2 to enable a fifth plane.. The problem lies in the MMU only ...

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