olivier.jan wrote: ↑Mon Jan 10, 2022 2:21 pm
Pretty common issues are the infamous MT RAM chips and the delay line. Mine had a dead RAm chip which caused it to go in storage in 84 until I found it in a bag and repaired it 2 years ago.
Yeah, I did look at the RAM suspiciously when I opened it up
Mine has TMS RAM installed.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
You have to upgrade it to 64k anyway in order to use U1MB and others, so it might be quicker to replace the RAM anyway.
Retro stuff
520 STF/ 1040 STE / Mega ST / 2 Mega STE / 2 H5
2 x 600XL with U1MB /SOFIA 2/ AVG CART / and a few 1050
Apple //c, Commodore 128, Mac Classic, SE/30, LC, IIvi and PB G3 (Clamshell)
Amiga 600 and a few 486 and 386.
Many Nintendo G&W and other electronic games from the late 70s/early 80s.
PhilC wrote: ↑Mon Jan 10, 2022 3:16 pm
@rubber_jonnie worth trying the piggyback ram trick check.
If I have some spare, I can. Need to rifle through my parts box, see what I have in there.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
olivier.jan wrote: ↑Mon Jan 10, 2022 3:19 pm
You have to upgrade it to 64k anyway in order to use U1MB and others, so it might be quicker to replace the RAM anyway.
True, but I'd rather get it working in original config first to make sure I have a solid platform for when I do upgrade. Also, as it's my first one, I don't want to complicate matters when troubleshooting.
Your point is a very valid one though.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
So, the 600XL has every last chip socketed and all single wipe sockets!!
I hate those buggers, I'll have to give them all a dam close inspection, and not to mention the sockets of two 74LS chips that the legs have gone black on. They need to come out for a clean and a spot of contact cleaner, then if it still doesn't boot, I think we'll need to get the scope out.
Very annoying as I have the Mac Classic, Aquarius and 600XL on the bench, so I need to make some space!!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
After doing some research, it seems that ROM, RAM & MMU are all the things that go bad, those and the single wipe sockets!!
So I am going to replace the sockets for the GTIA, Antic, SALLY, PIA, Pokey, OS and Basic. I have the sockets, all dual wipe, so i think it's worthwhile doing. I may also do the remaining smaller sockets, but want to get the main ones out of the way first.
I have a spare MMU from both the 800XL and 65XE due to their U1MB upgrades, so that's handy for testing, plus I have spare OS ROMs and a couple of Pokeys too from the same. That'll help at least isolate some of the ICs, but I may not be able to borrow much from the 800XL as a lot is socketed, and a few of the parts have wires soldered to them for the U1MB upgrades.
We'll see how we go.
@olivier.jan I have decided I may do the RAM upgrade to 64 K and have RAM on the way. As you say, I'll need to do it pre U1MB anyway.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Ok, so the 64KB ram is here now, so once I have some time I can get working on this machine again, as I have all the sockets I need to replace the awful single wipe ones it currently has.
I think I need to pull the lid off the 800XL too, see what parts are socketed that I can borrow for testing.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
rubber_jonnie wrote: ↑Thu Jan 13, 2022 2:21 pmI think I need to pull the lid off the 800XL too, see what parts are socketed that I can borrow for testing.
In early 800XL (not XLF) all Atari specific chips (excl. ROMs) are in sockets...
rubber_jonnie wrote: ↑Thu Jan 13, 2022 2:21 pmI think I need to pull the lid off the 800XL too, see what parts are socketed that I can borrow for testing.
In early 800XL (not XLF) all Atari specific chips (excl. ROMs) are in sockets...
The 600XL has everything in a socket for sure, my 800XL I think has a mix, as I did have to desolder the MMU in order to fit the U1MB. Trouble is I can't remember much more, so the lid will have to come off to help my crappy memory
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...