Replaced the fans on a few Socket 7 coolers. Unfortunately the 40mm fan I put on one sounds too loud, so I wired it up to the 5V on the IrDA header instead of the 12V.. Which is not very ideal. So I probably need to add a resistor to the +12V lead to drop it to 5V or something, because it works very tolerably at 5V..

Let's see, it's a 12V 0.11A fan so that means the fan itself has a resistance of 110R, and I want around 7V across it with a resistor in series so the resistor should be.. 80R roughly? I have some 150Rs so I'll add them in parallel. I have no idea what I'm doing doing to be perfectly honest, but this is as good as I remember high school physics from 25 years ago 🤣

Gotta consider the wattage too. Common through hole around these days are 1/8 of a watt rated I believe, though if you've got some older chunky monkeys they might be quarter watt. You're working with about 1.4 watts of power to the fan... so just sticking two 1/8 watt in parallel is gonna handle 0.25W of that, so you'll have a nice orange light and smoke signal to tell you when the fan is running. If you're gonna look for a 2W resistor now... above 1W they're usually done in an an oblong ceramic package, rather than cylindrical.... and commonly won't be all that many ohms... 1W parts are near pencil thickness.

But what ppl used to do in the day to "7V" mod fans was to connect between +5V and +12V... which works out fine as long as your fans are only a few percent of the loads on those.

BitWrangler wrote on 2022-02-22, 14:19:

Gotta consider the wattage too. Common through hole around these days are 1/8 of a watt rated I believe, though if you've got some older chunky monkeys they might be quarter watt. You're working with about 1.4 watts of power to the fan... so just sticking two 1/8 watt in parallel is gonna handle 0.25W of that, so you'll have a nice orange light and smoke signal to tell you when the fan is running. If you're gonna look for a 2W resistor now... above 1W they're usually done in an an oblong ceramic package, rather than cylindrical.... and commonly won't be all that many ohms... 1W parts are near pencil thickness.

But what ppl used to do in the day to "7V" mod fans was to connect between +5V and +12V... which works out fine as long as your fans are only a few percent of the loads on those.

Oh.. I hadn't considered the wattage. This is not a good idea AT ALL 🤣; I'll just keep the fan connected to the +5V and G on the IrDA connector then. Thanks for pointing out the stupid in my plan 🤣

Stupid question can the irda header handle the current draw of the fan long term?

chrismeyer6 wrote on 2022-02-22, 15:54:

Stupid question can the irda header handle the current draw of the fan long term?

No idea, but let's calculate.. Internal R would be 120R for an i of 0,11A at a V of 12v. That means at 5V, i would be 0,05A. P=iV so total power draw would be 0,25W.. I'm guessing that should be really OK?

Yeah that should be fine. Worst case you can make a molex plug and just wire it to the 5 volt pin and ground.

appiah4 wrote on 2022-02-22, 13:28:

Replaced the fans on a few Socket 7 coolers. Unfortunately the 40mm fan I put on one sounds too loud, so I wired it up to the 5V on the IrDA header instead of the 12V.. Which is not very ideal. So I probably need to add a resistor to the +12V lead to drop it to 5V or something, because it works very tolerably at 5V..
8><CUT

Maybe this is an option:
https://www.amazon.com/Noctua-NA-SRC10-Access … s/dp/B00KG3KELQ

Received another addition to my retro collection today:

So today's retro activity was getting this thing up and running. It had a few issues that I was aware of prior to buying, hence why it was fairly cheap.

Firstly, no power adapter and the proprietary connector. Thankfully, I'm such a massive hoarder that I don't tend to throw anything away, even if it seems useless. To that end, I dug through my parts drawer and found a spare plug & cable salvaged from an old Graphics Card fan, which fits the proprietary power connector perfectly. Found a spare 9V DC adapter, chopped off it's original connector and wired it up to the old fan plug, result - a working Atari 7800!

The 2nd issue I've worked around for now, but will need some thinking over. The RF port is damaged and I think ultimately my only option is to perform the composite mod. But for now I've worked around it, by simply running a bare RF wire into the damaged-beyond-repair socket, just have to take care not to knock out the cable/move the console.

Got a few Atari 7800 games ordered, but have been testing it all day with the built-in Asteroids & my Atari 2600 UnoCart.

First I had this - it's a GeForce 6200 - the card would work in DOS and at 640x480x16 in Windows but as soon as you did anything higher it froze with a corrupted screen... I didn't actually notice the caps on the eBay photos even though they were clear to see!

Now it's this it works perfectly...

SteveC wrote on 2022-02-22, 22:53:

First I had this - it's a GeForce 6200 - the card would work in DOS and at 640x480x16 in Windows but as soon as you did anything […]
Show full quote

First I had this - it's a GeForce 6200 - the card would work in DOS and at 640x480x16 in Windows but as soon as you did anything higher it froze with a corrupted screen... I didn't actually notice the caps on the eBay photos even though they were clear to see!
1024-1365.jpg

Now it's this it works perfectly...
4032-3024-max.jpg

If you REALLY want to have some fun, get a GeForce 6200LE. Its slower than a GeForce 6150SE integrated chip in every test. No joke.

Those capacitors are perfectly repairable. I don't think I've ever seen a polymer cap rupture before. I wonder what happened.

Kahenraz wrote on 2022-02-23, 04:24:

Those capacitors are perfectly repairable. I don't think I've ever seen a polymer cap rupture before. I wonder what happened.

Sacon happened 🙁 - they're not really polymer at all (with or without vent markings); try searchning for 'Sacon FZ'

Fixed an apparent dead 3.5" floppy drive in my HP Pavilion 8500.

Would not read disks at all. Took it out of the case, blew the dust out, popped the cover off and cleaned the heads with a Q-tip and 91% isopropyl and cleaned and re-greased the worm-drive.

Put it all back together and it works like new.

Next will be to see if I can fix the original 8x DVD drive which has a really hard time opening.

Wish I had all of the luck with floppy drives like you, man.

cyclone3d wrote on 2022-02-23, 07:04:

Fixed an apparent dead 3.5" floppy drive in my HP Pavilion 8500. […]
Show full quote

Fixed an apparent dead 3.5" floppy drive in my HP Pavilion 8500.

Would not read disks at all. Took it out of th case, blew the dust out, popped the cover off and cleaned the heads with a Q-tip and 91% isopropyl and cleaned and re-greased the worm-drive.

Put it all back together and it works like new.

Next will be to see if I can fix the original 8x DVD drive which has a really hard time opening.

Happens often, just head cleaning and works.
Dvds, one drive reads cds but not dvds. I cleaned it perfectly, degreased and regreased but nothing changed except that it has lower access times (loading the cd).
We need a tutorial and cleaning from a pro 😀

I have repaired some CDROM drives by recapping. Symptoms can be poor reading or no access at all. It's easy to remove couple of capacitors and measure ESR. There can be 10-20 caps so recapping is quite a pain.
Just couple days ago I had one old drive that had no access. ESR was couple of ohms on some I measured. Didn't have correct replacements so I just soldered 10uF ceramic in parallel to each one. After that it reads almost perfectly. I will recap it properly when I can source correct value caps.

Oh, then I have 3 SCSI Sony drives waiting for recapping. Job I have postponed due to depressing time/profit ratio.

The most frequent issue I find with CD-ROM failures is a belt gone bad. Unfortunately they are really annoying to source and replace. Anyone have a link for a good bunch for CD/Floppy drives on Aliexpress?

Belts come in all different sizes. There are also square and round belts. I think the best solution is to buy a kit of all different sizes and then try to find one that fits.

Not today but ordered the proper 387SX for the Compaq Deskpro 386s/20, largely doing that so I can run Links browser on it (I read the crash info from Links and apparently it needs an FPU - probably for the TLS 1.2/1.3 implementation). Same guy in France I bought the IIT 4C87 DLC from.

Lots of thoughts though.....

Still have been mulling over which PC's to keep and which to get rid of. The Compaq has really tickled my fancy by being a really good all-arounder in one machine, but I still really like my 486 Desktop and my Versas as well. The Compaq covers the 286s territory so I'm thinking maybe the GEM 286 might go, sadly for as long as I've had that machine, I just don't use it that much anymore.

Still contemplating whether to upgrade the NEC Ready to a MediaGX or some other Socket 5 compatible CPU to go with the Banshee. I also have my FitPC Slim to play with as well which takes up about 1/72 of the space of the NEC, and I have that Versa P/75 as wel (but that won't run a Banshee card), and the FitPC does not have 3D acceleration so...uh...not sure there.

I think the goal should be only to have as many PC's as I have the CRTs for, which would be 4 - Tandy 1000, Compaq, 486, and the VersaDock. The Moondog gets a pass since it's connected to my TV....now that I think about it though.....

I did play some Quake on the Moondog....how the heck is a PC Chips M912 with 32MB of RAM and a Cirrus CLGD5421 with 1MB of VRAM able to run Quake so smoothly in DOS? Seriously, it was slightly out-performing my othe rDX4-100 with the same CPU, double the VRAM, double the RAM, and an S3 with 2MB - and with UniVBE loaded. Looks like that Moondog might be more of a winner than I realized. It's like it's happy being a DOS "Game Console" in a Baby-AT Mid-tower.

Kahenraz wrote on 2022-02-23, 15:27:

Belts come in all different sizes. There are also square and round belts. I think the best solution is to buy a kit of all different sizes and then try to find one that fits.

Agree, probably best to buy a kit, you can find them on eBay, search for something like this "20PCS Assorted Common Rubber Belt".

The problem with buying a single size belt is that from drive to drive they use different size as well, so having a mixed assortment is actually quite handy. The problem with buying a mix bag of belts is that you end up with a bunch of belts you never use because you only end up using belts in a certain range.