nfg.forums

NFG Forums => RGB + Video Discussions => Topic started by: 2N1305 on March 08, 2012, 05:46:44 PM

Title: concatenated IC3G (and IC4L) + other info
Post by: 2N1305 on March 08, 2012, 05:46:44 PM
quote author=Live_Steam_Mad link=topic=1592.msg30848#msg30848 date=1315349576]

 But why does the NES or Famicom not need this LS245 chip and the PC10 does?!  
[/quote]

Good question

Quote from: Live_Steam_Mad on September 07, 2011, 08:52:56 AM
i.e. you are going to need to add a hex inverter (just like in PC10 IC 3G) to the Veroboard as well, and there are also a concatenation of 3 inverters chained together, output to input (IC 3G, pins 1,2,3,4,5,6) which I don't understand the purpose of, and 2 caps needed (PC10 C40 & C41) and an input to pin 1 of the hex inverter from a place on the PC10 that I do not understand where it comes from. And there is an inverted input needed for "G" on the LS245. So unless someone can explain to me what all these inverters in this last paragraph here are meant to do, or more importantly, how they are all wired, I cannot proceed with this experiment.

Those three inverters concatenated together form a delay line, (a few dozen nanoseconds, basically the prop. delay of those inverters added together)just like the ones in the LS367A going to the strobe pin (G) on IC3K. Except the latter are possibly to fix the WRITE time difference between the Famicom and the PS10. But don't quote me on that, I'm an analog guy... :)

Also, that "input from the place on the PC10" is ßΓπ, getting there... Φ got it Φ2, in greek, phase 2. Meaning, I would guess, "clock 2", as phi is often used to name a clock signal. It is generated by IC1H , pin 31, called Φ2 and is sent a21 on the ROM connector, the aforementionned IC3G (pin 1), and IC2L, and finally pin 6 of IC8F. Also, 8E and 8F. All these run on the same clock, rather the same PHASE of clock, because somewhere (I haven't looked), but there is phase 1... lol

seriously, there is. Anyway it's effin' late and I'm hittin' the sack. cheers

2N
Title: Re: concatenated IC3G (and IC4L) + other info
Post by: 2N1305 on March 08, 2012, 05:52:08 PM
I am sorry. this was supposed to be a reply to a post on another thread, which I forgot because it was a link given to me by a friend. It had to do with the RGB conversion circuit and the Famicom and PC10 schematics, with a user asking what the purpose of the three inverters in series was. Anyway, it's no use now, I am too tired...
stupid timeout session
I tried...

cheers,

2N