Search found 132 matches

by rubber_jonnie
Sat Feb 24, 2018 10:49 am
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 8
Views: 389

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

redhawk668 wrote:
Fri Feb 23, 2018 6:30 pm
I’ve done a 320 kb upgrade on a 130XE, I had to desolder the second bank of ram chips. My solution uses a 74LS158, a 33 ohm resistor and some wire. I used the 256 kb drams from a dead Atari ST.
Any chance of some pics and details?
by rubber_jonnie
Fri Feb 23, 2018 11:46 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

Ok, they're quite a bit different :o
by rubber_jonnie
Fri Feb 23, 2018 11:44 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 rubber_jonnie
Fri Feb 23, 2018 4:23 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?
by rubber_jonnie
Fri Feb 23, 2018 3:48 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

I've never taken my 2600 apart, so have no idea of how much space there is in it.
by rubber_jonnie
Fri Feb 23, 2018 3:36 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

exxos wrote:
Fri Feb 23, 2018 3:31 pm

Same thing I presume, looking at this diagram...
I may try both approaches, see what turns up, as I have a drawer full of bits to tinker with.
by rubber_jonnie
Fri Feb 23, 2018 3:34 pm
Forum: HARDWARE DISCUSSIONS
Topic: PAK-68/20 - Repository
Replies: 10
Views: 316

Re: PAK-68/20 - Repository

Where did you find the PGA114 socket? I've searched, but they seem really difficult to find. I now have the 68020, the FPU and the GAL's and the PLCC68 socket. That was'nt a big problem to find. Rest of the stuff will be ordered from DigiKey. If I can't find a 114 PGA socket, I think I will make a ...
by rubber_jonnie
Fri Feb 23, 2018 3:23 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

Actually, reading what you wrote made sense, well explained :dualthumbup:

One thing I don't understand is, if the signal is available there, why remove the modulator?

As for Q4, I'm assuming that's an audio amplifier that feeds into the modulator, so why would you want to remove it?
by rubber_jonnie
Fri Feb 23, 2018 3:05 pm
Forum: 8 BIT CORNER
Topic: Atari 2600/7800 Composite MOD
Replies: 12
Views: 53

Re: Atari 2600/7800 Composite MOD

Ahh, cool I will have a look, thanks.
by rubber_jonnie
Fri Feb 23, 2018 2:33 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 r...