Search found 1297 matches

by exxos
Sat Feb 24, 2018 12:47 pm
Forum: MEMBER BLOGS
Topic: Top of the pile
Replies: 9
Views: 77

Re: Top of the pile

atari030 wrote:
Sat Feb 24, 2018 11:29 am
You mean the 16x 33 ohm resistors, right? STFM's don't have this cap.
No, the SIL arrays normally 10K. STFM's do have the cap also. viewtopic.php?f=41&t=507
by exxos
Sat Feb 24, 2018 10:37 am
Forum: MEMBER BLOGS
Topic: Top of the pile
Replies: 9
Views: 77

Re: Top of the pile

ah, main smoothing cap. If it works without it then you have a noise problem most likely. Swapping the address & databus arrays for 2.2K will most likely help.
by exxos
Sat Feb 24, 2018 9:00 am
Forum: MEMBER BLOGS
Topic: Top of the pile
Replies: 9
Views: 77

Re: Top of the pile

can you post it a image of the area on here, I can't see it anywhere :roll:
by exxos
Fri Feb 23, 2018 7:09 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

I thought I would post this here as I've been puzzling over this for the past few hours... It seems the TIA chip has a different pinout for PAL & NTSC machines. This could be why when I tried my mod originally, it failed miserably as I could have been following a NTSC pinout for the TIA :roll: It is...
by exxos
Fri Feb 23, 2018 4:43 pm
Forum: BENCHMARKS
Topic: STFM PAK020 - 16MHz 32BIT ROM
Replies: 3
Views: 174

Re: STFM PAK020 - 16MHz 32BIT ROM

Quick Q here, I presume the original 68K cpu is removed from the mainboard, and a socket put in it's place, or is the PAK soldered into where the 68K used to be? I had to put it into a socket, simply because as the board is so large it would not seat down to the motherboard as the MMU is in the way.
by exxos
Fri Feb 23, 2018 3:39 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

I may try both approaches, see what turns up, as I have a drawer full of bits to tinker with. That would make my life a lot easier ;) If the 4050 was removed, little plug-in board could be put there tweaks and fixes for the video drive.. Though would still need some wire links for the colour and au...
by exxos
Fri Feb 23, 2018 3:31 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

One thing I don't understand is, if the signal is available there, why remove the modulator? I think it is to reduce interference on the video signals... As to if it actually helps or not I don't know.. But it makes sense to remove it.. As for Q4, I'm assuming that's an audio amplifier that feeds i...
by exxos
Fri Feb 23, 2018 3:14 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

I did look into this several years ago as well.. But basically I used a video generator chip, I think it was to generate RGB signals for scart. I can't remember what chip it was, or I can remember is the results were horrific and I just gave up with it. This page has a few things tried out.. http://...
by exxos
Fri Feb 23, 2018 2:46 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

This caught my attention as well ... http://thevowel.com/blog/2012/06/29/upgrading-my-atari-2600/ Mostly I was just looking at circuit diagram itself... Seems difficult to work out as a seems to be multiple revisions which all look very similar, but the part numbers a very much different.. Not hundr...
by exxos
Fri Feb 23, 2018 2:27 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

:bravo: I did see that that a few days ago. A lot of them seem to go down the similar route. What I don't really understand is why the transistors even needed because there is a buffer chip in the video with the resistor ladder anyway. A lot of them seem to hack to bits a lot of the circuit, then re...