Activity

foft's activity

From 06/28/2017 to 07/27/2017

FO 09:06 PM EclaireXL Bug #56: Galaxian Cartridge crash: This works on the latest core I'm using (lets call it v15 - address decoder rework!) foft

FO 08:14 PM EclaireXL Feature #55 (New): Replace main CPU: I really find the stack based zpu annoying to debug. Also as its setup the rom is full.
Consider replacing with something newer, also with gcc support, such as https://github.com/SpinalHDL/VexRiscv. foft

FO 09:47 PM EclaireXL Bug #25: F10 Hard Reset Ignore inserted cartridge (Core v7): This is the last thing remaining for V15. In order to do it (simply) I decided to allow off PBI access from turbo mode and zpu. That seems to work now, except its failing timing. I think I need to plumb the internal freezer in differentl... foft
FO 09:44 PM EclaireXL Bug #25 (In Progress): F10 Hard Reset Ignore inserted cartridge (Core v7): foft

FO 01:25 PM EclaireXL Feature #24: A board with Atari SOUL!!!! (ROM in block ram support): I'm using block ram in the FPGA for the OS ROM and BASIC. It can be read in 2 cycles and written to in 1 cycle. SDRAM takes about 5-6 iirc. So in turbo mode, with no cpu cache, this makes a huge difference in speed. foft

FO 09:26 PM EclaireXL Feature #24: A board with Atari SOUL!!!! (ROM in block ram support): Also of course nice and fast vs uncached sdram...
sysinfo fp test from 6x->20x :-) I probably need a cache to get this closer to 30-40x, but that will take some work. foft
FO 09:13 PM EclaireXL Feature #2: PBI support: Added antic refresh cycles foft

FO 09:28 PM EclaireXL Feature #51: Debug port: I have a first cut of this building. This will be part of the v15 core.
Next I need to build the capture software to stream this into the PC. Then some post-analysis software, probably a hacked up emulator. foft

FO 09:41 PM EclaireXL Bug #49 (Closed): CORE13 - NTSC/PAL switching: foft
FO 09:40 PM EclaireXL Bug #49: CORE13 - NTSC/PAL switching: Fixed, will be in v15 when I release it. foft

FO 09:31 PM EclaireXL Bug #49: CORE13 - NTSC/PAL switching: Trying to fix this one, but its nasty. I need more brain cycles to fix it... foft
FO 09:29 PM EclaireXL Feature #14: Svideo core for first prototype: Hmm, just reading that IRE is _relative_ so that might be why increasing voltage didn't make anything brighter!!
https://en.wikipedia.org/wiki/IRE_(unit)
So I wonder if I could have a 0V-0.5V signal that uses the correct relative s... foft

FO 10:50 PM EclaireXL Feature #14: Svideo core for first prototype: For anyone with composite/svideo setup. Please can you tell me what you think of svideo_gtia6.sof vs the previous version.
This is generated more the 'atari way' - i.e. off hue/brightness with phase shifts, rather than being based on ... foft
FO 11:42 AM EclaireXL Feature #14: Svideo core for first prototype: I mean svideo and composite, it's the same thing pretty much.
I've got the gtia style one running pretty well for ntsc now. Its interesting to implement if nothing else:) foft
FO 01:10 PM EclaireXL Bug #54: GTIA issue when Turbo > 4X: Yeah, this kind of test program is very helpful. Thanks. foft

FO 05:05 PM EclaireXL Feature #14: Svideo core for first prototype: That works, kind of! Basic screen and star wars shields look the correct colours, but I have no red. Also very grainy and svideo is a single colour?! foft
FO 12:59 PM EclaireXL Feature #14: Svideo core for first prototype: Writing an 'atari-style' implementation instead of going via RGB. Fixed saturation, simple phase shift for colour. foft
FO 07:10 AM EclaireXL Feature #14: Svideo core for first prototype: Interesting...
http://atariage.com/forums/topic/29621-atari-video-circuits-experiment/
So fixed saturation (except gray), just phase shifted for the cols. Then add luma. Might try that rather than generic rgb component. foft
FO 03:59 PM EclaireXL Feature #53 (Closed): Add version number to settings: Add version number to settings foft

FO 10:15 PM EclaireXL Bug #52: Atari Control Picture: I checked an older core in case I introduced it with the antic timing changes for pbi. Was bad then, so unrelated.
This is a nice static picture to debug in sim or signaltap. I like this kind of test case:-) foft
FO 10:10 PM EclaireXL Feature #14: Svideo core for first prototype: Added a poke 712,15 for comparison of max values. Interesting how the amplitude for basic 'blue' is so much higher yet the peak amplitude is comparable...
Atari:
!composite_atari_max.png!
Eclaire:
!composite_eclaire_max.png! foft
FO 09:54 PM EclaireXL Feature #14: Svideo core for first prototype: I mean see how the 'white' on ready already takes most of the range, without trying to increase it. foft
FO 09:54 PM EclaireXL Feature #14: Svideo core for first prototype: Atari
!composite_atari_basic.png!
Eclaire
!composite_eclaire_basic.png!
We have a range of 0-1v on the DAC. 0-0.3V sync and 0.3V-1.0V is set by changing the dac level. So trouble is its not really enough. Might still need to chan... foft
FO 09:50 PM EclaireXL Feature #14: Svideo core for first prototype: Added traces of Atari basic from the scope, to see the voltage level differences.
Eclaire is driving my monitor, Atari is through a 66ohm resistor (little low, so voltage is suppressed a little).
Still, a stark difference! foft

FO 08:59 PM EclaireXL Bug #49: CORE13 - NTSC/PAL switching: I think I've identified the problem. If the zpu happens to exit the menu at the end of an 'original' cycle the pbi logic can block the response from a memory access. Now to think about how to implement this in a better way... foft

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