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Comment by msla | Hacker News Reader

> No 3rd party libraries, only C standard library and OS libraries for window, input, etc.

It might be interesting to do a survey of OSes and pick carefully. I think Amigas were used to do TV work back in the day...

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Amigas used a CRT as a display (had to do that on more than one occasion). Amigas also had a few different expansion cards that made doing TV work possible. The Toaster was the biggie for doing actual TV work and not just displaying a signal. There were other cards that I'm losing the names of right now. The card that allowed you to move your animation frame sequences to the hard drive built onto the card to play back in real time as component video. Then there was the Kitchen Sync that allowed a couple of non-genlocked inputs as usable/stable sources for the Toaster.

Edit: By CRT I meant just any monitor with RCA composite video input compared to a monitor with a VGA type input.

Edit2: remembered the name of the card the "PAR" (personal animation recorder). This site has some info on several of the boards including the PAR: https://shop.myamigashop.com/blogs/blogs/information-page-fo...

Genlock support in the chipset was quite neat. The genlock contained a Phase Locked Loop that provided the 28.63636 MHz clock input on the video connector so that the entire system ran off that clock which was synchronized to the video stream. One of the bit planes then controlled if the Amiga's video would overlay the external video source. That was incredibly forward thinking of Jay Miner compared to the offerings of other platforms at the time.

Are you saying Jay Miner created Genlock or just that it was forward thinking to include on the Amiga?

I'm not sure I'd agree with either, as I don't recall the Amiga having Genlock abilities at all. Only 3rd party expansion cards gave the Amiga the ability to Genlock to external video sources so that it was in sync with the rest of the house. For proper Genlock, you have to have some sort of input (typically a black video signal) to use as a sync source, and I just don't recall an Amiga natively having any kind on input like that.

The horizontal and vertical syncs[1] (along with the system clock) can be inputs on the video connector. That's what enabled all of the 3rd party genlock hardware. It was designed into the Agnus from the start.

Without that you'd need an external framebuffer like an infinite window TBC, which is much more expensive.

[1] ERSY mode: http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_gui...

Right, 3rd party, not native to the Amiga which the person I replied to was seemingly implying.

No I get what's meant though. The fact that the Amiga apparently had the native ability to sync its PLL to incoming sync signals (and presumably other clocks are derived from that?) is, for the time and for a general purpose micro at least, nothing short of amazing to me.

I disagree for the reason that the hardware that is synchronizing the video is the Amiga itself, not the 3rd party hardware.

https://retrocomputing.stackexchange.com/questions/22320/wha...

The PLL is external, but the chipset had the ability to accept an external clock from the start in the Amiga 1000.

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