Oops, my obsession with computers from my childhood strikes again!

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stephen_usher
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by stephen_usher »

:dualthumbup:
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by rubber_jonnie »

So, I like to power on my machines regularly to be sure everything runs fine, and I usually leave them running during the day as I work from home and my office and retro area are the same room.

And boy has the Apple ][e been a bit unreliable, with the RAM/80 column card 'disappearing' and random floppy unreliability. The only thing that seems to have been unaffected is the Mockingboard sound card.

It seems fixed now, basically the edge connectors of the RAM/80 column card and home built (Not by me, that's how it came) FDD controller needed to be cleaned and seem to suffer from oxidisation despite being gold plated.

I've also noticed whilst doing this that when the machine starts from cold the display is shimmery, but once warm it really does stabilise quite a bit, so I'm thinking I might have a look at the caps in the video circuit, see if replacements might make it look sharper when cold.


EDIT: Just a short time later and the RAM/80 column card has vanished again Merdé!!!
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...
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stephen_usher
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by stephen_usher »

Are the sockets getting loose in their old age?

I'd spray Electrolube EML down there and wide the contacts with folded paper to polish them. :-)

I take it that you've checked the +5V rail for ripple with your 'scope?
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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PhilC
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by PhilC »

What Mr Usher says and have a good look at the ram card socket itself. If you are careful you can retension any wayward pins but it does sound like you have a power supply issue of some description as well.

My Apple //e is actually one of my more reliable machines believe it or not.
If it ain't broke, test it to Destruction.
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HigashiJun
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by HigashiJun »

rubber_jonnie wrote: Mon Mar 20, 2023 4:31 pm Merdé!!!
I guess you wanted to say "Merde !!!"...

;)
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rubber_jonnie
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by rubber_jonnie »

stephen_usher wrote: Mon Mar 20, 2023 7:50 pm Are the sockets getting loose in their old age?

I'd spray Electrolube EML down there and wide the contacts with folded paper to polish them. :-)

I take it that you've checked the +5V rail for ripple with your 'scope?
I did hit the sockets up with Electrolube as it goes but it seemed to make little to no difference. I also cleaned the contacts with IPA on the cards. However, on powering down from an instance where the RAM card was not picked up and leaving it to cool off, the problem went away

As for cleaning and tweaking the sockets, yes I will do that when I have some more time, hopefully at the weekend. I haven't checked for ripple yet either, though the RIFAs have been replaced, but not any of the other caps.

The joys of being a retro computer owner :)
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...
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rubber_jonnie
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by rubber_jonnie »

PhilC wrote: Mon Mar 20, 2023 10:23 pm What Mr Usher says and have a good look at the ram card socket itself. If you are careful you can retension any wayward pins but it does sound like you have a power supply issue of some description as well.

My Apple //e is actually one of my more reliable machines believe it or not.
I may try running it with no RAM card for a bit and see if it makes a difference, but I will have a closer look at the socket, see what I can see.

I wouldn't be surprised if the PSU is in need of a service.
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...
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rubber_jonnie
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by rubber_jonnie »

HigashiJun wrote: Tue Mar 21, 2023 3:26 am
rubber_jonnie wrote: Mon Mar 20, 2023 4:31 pm Merdé!!!
I guess you wanted to say "Merde !!!"...

;)
Who doesn't :)
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...
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HigashiJun
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by HigashiJun »

:roll:
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rubber_jonnie
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Re: Oops, my obsession with computers from my childhood strikes again!

Post by rubber_jonnie »

Ok, had a quick 5 minutes to test the AC ripple on the 5v line and it's 36-40mV peak to peak. From what I can see, that isn't too bad.

However I'm now getting some other weirdness. With the colour killer set to off, I get no video out, but you can see from the floppy emu that it is booting.

If I set the CK switch to on, I get monochrome video back. If I switch the CK switch back off whilst running, I get a colour display.

If I then reboot with the CK switch off, I get no display. Very strange.

So, I'm going to go find the schematics and have a look see.
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...
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