 Documentation about the Vampire hardware |
|
|---|
| | 
Gunnar von Boehn
(Apollo Team Member)
Posts 6214
03 Apr 2018 09:21
| Now that Vampire can boot EMUTOS, we like to complete to hardware compatibility to ATARI.
I like to double check to make sure
that the SAGA chipset does provide all GFX-Resolutions and color format needed to run all ATARI applications.
Can you please help me to complete the list of using Screen formats on ATARI?AFAIK the ATARI did support 640x400 1 Plane
640x200 2 Plane (Word/interleaved)
320x200 4 Plane (Word/interleaved) Falcon than added
8 Plane (word/interleaved)
16bit direct color
| |
| | 
Vojin Vidanovic
(Needs Verification)
Posts 1916/ 1
03 Apr 2018 16:14
| Gunnar von Boehn wrote:
|
640x400 1 Plane
640x200 2 Plane (Word/interleaved)
320x200 4 Plane (Word/interleaved)
Falcon than added
8 Plane (word/interleaved)
16bit direct color
|
Atari guys seems to differ ST modes, TT modes and Falcon ones. Listed are true, while TT modes have some weird resolutions like Color: 320×200 (16 color), 320×480 (256 colors), 640×200 (4 colors), 640×480 (16 colors), palette of 4096 colors
Duochrome: 640×400 (2 colors)
Monochrome: 1280×960 mono TT high with ECL 19 in (483 mm) TTM195 monitor
| |
| | 
Markus (mfro)
Posts 99
03 Apr 2018 16:52
| True for original Atari machines.
Depending on the availability of a suitable VDI (literally: Virtual Device Interface) driver, however, GEM supports basically every resolution you can think of.
Third party graphics cards (expensive!) were available (with card-specific drivers) with up to 1280 x 1024@24 bit colour. Some of them (because of their PC world offspring) with rather weird (e.g. byte swapped) pixel formats.
| |
| | 
OneSTone O2o
Posts 159
03 Apr 2018 22:05
| The addon graphics cards for the ST/TT/Falcon are interesting, but IMHO not for Vampire as it provides it's own SAGA graphics card which is capable of doing more resolution and colors. So none of the - for example ATI Mach32/64, ET4000 or Matrix-cards resolutions need to be emulated on Vampire. The original Atari chipset graphics modes are much more interesting. And, yes, we differ in the four generations of machines: ST, STE, TT, Falcon.
ST:
ST-high: 640x400 monochrome
ST-medium: 640x200 in 4 colors in bitplanes,
ST-low: 320x200 in 16 colors bitplanes.
The colors in low/med are selectable out of a palette of 512 colors.
STE: same as ST, but a palette of 4096 colors. Aditionally it has some support for hardware scrolling. For full software compatibility to STE (and Falcon) the ST-blitter should not be forgot. @cietz has rediscovered original circuit diagram of ST blitter chip.
But this is only the standard. By software- or hardware tricks, these ST/STE resolutions can be enhanced to Overscan. This is quite tricky as the shifter was not designed for this, these modes are using design flaws of the chip. Monochrome overscan only could be done by modified hardware (called "Autoswitch Overscan", it modifies some shifter/glue interlinked signals), it was up to 762x576 , color overscan also in software, by swithing very fast forth and back between 50+60 hz color modes and 70hz monochrome mode in the right moments. That means, itÄs quite very timing critical in software. To understand better how this works you would need to have contact to authors of scene demos and ST/STE emulators which are able to emulate these overscan tricks. This is that you exactly understand how it works and how to detect such programs and emulate the overscan. I think this is a challenge. But on the other hand, as 68080 never will be "timing and cycle accurate" to a real 68000 (it does not make sense for an accelerator), one must ask if the software overscan tricks should be emulated. Hardware overscan might be more interestig.
TT shifter: Can support all ST/STE modes, plus
TT high: 1280x960 monochrome
TT low: 320x400 in 256 palette registers (8 bitplanes) out of 4096 colors
TT med ("VGA"): 640x480 in 16 palette registers (4 bitplanes) out of 4096 colors
Note, that ST high (640x400 monochrome) on TT is "duochrome", that means you can choose the "white" and "black" color out of the 4096 color palette. After reset, it should be black&white like ST.
Falcon videl chip is another story. It can support all modes of ST, STE and TT , but beyond this it is freely configurable to all resolutions which are doable with given memory performance. By default videl is switchable between 16 and 32 Mhz base clock and it is possible to add external clock generator of 40 or 50 Mhz (which needs some cooling), there is hardware like "Screenblaster" and others to add the external clock. On 32 Mhz 800x608 in 256 colors is a popular resolution, just by software. With higher memory speed (bus clock accelerated falcon board) also higher resolutions or colors are possible without speed down the CPU (this is very similar to Amiga chipmem behaviour). Videl is very flexible.
Please note that base adress of video memory is freely configureable in available ST ram by pointing a regster in ST/STE/TT-Shifter and Videl.
I recommend you to rea EXTERNAL LINK PDF free download. Pages 832ff for ST and pages 1048ff for TT modes. There, these resolutions and their memory organisation is decribed in detail. STE is only little change from ST, just color palette like TT. Also other registers of the video hardware are described there. For Falcon you should see other sources, I think I don't have, maybe Markus_mfro has?
For more compatibility of the video hardware you should have contact to coders of scene demos and emulators, like hatari emulator, open source based on uae. Also MiST FPGA Atari ST emulation could be studied.
In a next step, consider also to implement ST/STE/TT/Falcon audio hardware. STE and TT have the same DMA-sound hardware, plus ST's Yamaha chip, Falcon has all of them.
| |
| |
Vojin Vidanovic
(Needs Verification)
Posts 1916/ 1
03 Apr 2018 22:27
| oneSTone o2o wrote:
|
For more compatibility of the video hardware you should have contact to coders of scene demos and emulators, like hatari emulator, open source based on uae. Also MiST FPGA Atari ST emulation could be studied.
In a next step, consider also to implement ST/STE/TT/Falcon audio hardware. STE and TT have the same DMA-sound hardware, plus ST's Yamaha chip, Falcon has all of them.
|
Hope v4 FPGA space is sufficient for 2)
Here seems to be Mist Atari Cores
EXTERNAL LINK
And Atari forums are alive and kicking
EXTERNAL LINK
Who will present a Vampires?
FPGA clone section exists, with Mist, as well as Others
Mist
EXTERNAL LINK Other FPGA clones (no mention of Vamp yet)
EXTERNAL LINK
Hatari source code
EXTERNAL LINK
| |
| | 
Uros Vidovic
Posts 31
04 Apr 2018 07:40
| Lowest resolution Atari clone has to support to be interesting to me is 1600x1200 32bit. I propose to do SUPER VIDEL compatible gfx chipset. But as already said ... Atari OS can use any resolution if drivers are available.
| |
| |
Gunnar von Boehn
(Apollo Team Member)
Posts 6214
04 Apr 2018 08:19
| The precise my question and to let us stay here on topic. The question was NOT what GFX formats some PC GFX chips support.
SAGA does support all of them anyway. The question was which GFX formats to real ATARI chips support.
And to doublecheck if my summery was complete 1 PLANE (word interleaved)
2 PLANE (word interleaved)
4 PLANE (word interleaved)
8 PLANE (word interleaved)
16 Hicolor Direct Thats is all, right?
There was no 8bit Chunky mode?
| |
| | 
Anthony Jacques
Posts 11
04 Apr 2018 08:56
| Gunnar von Boehn wrote:
|
The precise my question and to let us stay here on topic.
The question was NOT what GFX formats some PC GFX chips support.
SAGA does support all of them anyway.
|
For image dimensions / frequency, that question is still tricky because the Falcons videl chip is very configurable and so supports a lot of resolutions simply by changing register values and most Falcon users use software to adjust them to get higher than “standard” resolutions. I think if your hw is capable this shouldn’t be out of scope.For the ST it’s also tricky if you count all the democoder tricks to increase screen area but they all rely upon cpu & hw cycle exact behaviour so i would agree is out of scope.
Thats is all, right?
There was no 8bit Chunky mode?
|
That is correct. The official Falcon TOS apparently supports a 8-bit chunky mode but the HW doesn’t support it.
| |
| |
OneSTone O2o
Posts 159
04 Apr 2018 16:16
| I think supervidel could be an option for some compatibility issue, maybe also the Firebee enhanced mode (it's unfortunatelly different from Supervidel, but both base on Falcon Videl), but thanks to Vincent we have already SAGA VDI driver (which is based on Supervicdel VDI), so for 'clean' software that should be great. The software overscan tricks are not that important now, but they should be kept in mind, maybe one day Apollo team implements something to switch down to a real 68000 (or good vhdl) for nostalgic reason besides the 68080 (example, optionally there was similar solution for c't magazine PAK68/2-3 to switch back to 68000)
| |
| | 
Olivier Landemarre
Posts 147
04 Apr 2018 17:43
| Gunnar von Boehn wrote:
|
The precise my question and to let us stay here on topic.
The question was NOT what GFX formats some PC GFX chips support.
SAGA does support all of them anyway.
The question was which GFX formats to real ATARI chips support.
And to doublecheck if my summery was complete
1 PLANE (word interleaved)
2 PLANE (word interleaved)
4 PLANE (word interleaved)
8 PLANE (word interleaved)
16 Hicolor Direct
Thats is all, right?
There was no 8bit Chunky mode?
|
I think for emulation only interested format are 1 plane, 4 planes word interleaved, 8 planes word interleaved and 16 hicolor direct. Even 2 planes is near not used because too low number of colors! There TT formats but does it is interesting to include it? I don't think so. There is no 8bit chuncky mode on real Atari hardware.
If you have some color issue on 8 planes there is some strange arrangement in order of some colors, I don't know how hardware manage this but I have connection when I call VDI if you see some wrong color (1 to 15 and 255)
| |
|
|
|
