Re: Merging video output?
Posted: Thu Sep 13, 2018 9:01 am
You guys are totally crazy. And I love it!
Defence Force forums
That's probably the most hard to achieve from your list ...
Indeed with two ULA, difficult, but with 3, it's trivial as you described, and, I did some tests earlier in the thread:mikeb wrote: ↑Thu Sep 13, 2018 6:12 pmThat's probably the most hard to achieve from your list ...
The ULA as it stands cannot be convinced to do that, and I'm struggling to think how two ULAs could work together to confound that limit.
Yes, you lose the first column, but that's an acceptable thing, and on the Oric you never notice anyway since the attribute change appears in black and is merged with the border, so not an issue.
Oh, clearly I plan on having the VSYNC trick applied to all the connected machines, and the idea is to use the VIA timers to synchronize the machines over long operations: I assume that we can have the entire machine reset in a known state, including the 6502 and 6522?mikeb wrote: ↑Thu Sep 13, 2018 6:12 pmAs to syncing the Orics together, aside from the hardware VSYNC loopback into the cassette port trick -- don't forget my comments section in the PDF on putting two/three ULAs in one Oric (manipulating address lines) would mean you wouldn't need to sync between the two computers at a software level in the first place.
So many possibilities!
In my idea, 4 machines was the ideal setup because it's the minimum amount of hardware to reach 50fps full screen HIRES animation.iss wrote: I don't want to interrupt discussion but just to share that after I created real button de-bouncer now synchronization is simple and works fine!
Let's make some final decisions related to the design of the future needed hardware:
1. How many Orics we need ? In my opinion 4 is OK! I'm asking because this is related to the design of the future video mixer.
2. Do we need 16K RAM overlay? It's possible but I think it will be just an unnecessary complexity.
And don't forget about the audio possibilities - with 4 Orics we will have real quadraphonic sound!
(this is of course a joke although it's actually the reality )
I think this is why the values of "mixing" resistors I quoted were used, to get a better ratio of R-G-B.iss wrote: ↑Sat Sep 15, 2018 4:26 pmThere is one small detail related to the direct video mixing - RGB outputs are not TTL levels but the signal goes through resistors 200 Ohms. The result is absolutely similar to the internal audio channel mixing discussed in Oric's 8912 volume scale.
But this actually will lead to nice effects .
It's not my maths, those resistor figures were from Oric Owner, but it's my explanation, given that they didn't justify why those particular values