Building a Win95 PC, mobo just came today. Was hoping some of you could answer some questions I have.

Grumgi

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Jan 23, 2020
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Well, before anything, I guess I should say hello. I'm Grumgi, an amateur hobbyist based in NY. With that said, I recently decided to build an early 90's PC. I know installing 95 isn't *quite* period authentic, but realistically speaking it's entirely plausible that a pc of this caliber, had it existed in 1995, would've been upgraded to 95 from 3.1. Also, most importantly, I just really like the OS.

But onto the meat of post. I have a few questions regarding the mobo that just arrived today. There are a few things I noticed about the board, which you yourself can see in the pictures below, which I am unsure of their ability to function or the reasons why certain parts are there. Before I go on, I should mention that the seller I purchased from claimed it was pulled from a working machine. I'm not saying the guy would lie, but just because it works when he tested it doesn't guarantee the thing will work now. The point of contention revolved around the ni-cd battery, which looks like it has corroded and doesn't quite look to be in working order. I would test it, but I don't have the tools to nor the knowledge to either. Or the components, for that matter. Essentially what I'm asking is if I should replace it before going any further with the build.
Secondly, you'll notice the presence of what looks to be a bunch of tiny jumpers. I'm not sure if they should be there or not; I was hoping one of you could help out with that.
My final question is regarding 5 1/4'' floppy drives, specifically one from an Apple II. Working with these drives because they usually go for less money on ebay and the like. I know one needs a certain ISA card to hook up Apple II drives to begin with, but would it work with a Windows/DOS PC? Or are there certain drivers I need? Or would it just straight up crash and burn?

By the way, I apologize for the long post, especially as my introduction lol
 

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grommile

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Nov 24, 2019
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Northampton, UK
If you see that kind of battery and don't trust its condition (and I prrrrobably wouldn't trust it, looking at those photos), I would very much recommend replacing it before you turn on the equipment.
 
May 22, 2019
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Hello, and welcome to the party! We have a good bunch, here. Nobody bites (without an invitation), and there are some knowledgeable folks here.

Definitely pull that battery. While the computer will work without it, you'll want to have one in there to preserve your CMOS settings while the computer is offline. This also runs your real time clock, so without that battery, your computer won't know what time it is when you turn it back on.

Rather than trying to solder on another lithium battery pack, I would suggest installing a AA battery holder with the appropriate number of cells (probably 3.)

Disk drives... I would suggest not even trying.

Apple used the Shugart SA-390, which is apparently just an SA-400 that failed factory testing. The drive supported 35 tracks and (on the Apple) supports a recording format known as "Group Code Recording", or GCR. Apple, Commodore, and a few other companies used GCR on 35-track disks.

PCs used 40-track drives and 9 sectors per track, for a total of 180K per side. Since these drives use a stepper motor to advance the head, you cannot safely plug a 35-track drive into a 40-track controller. Passing track 35 might damage the mechanism at work, or just be unreliable at best. (Commodore's drives are actually capable of 40 tracks, but not reliable past track 35, so CBM DOS only supports 35 tracks, or 140K per side.)

And honestly, I would not even want to try to put an Apple ][ drive in a PC. The PC compatible 5.25" diskette drive is the most popular floppy drive in history, so it should be the easiest to obtain used.

Jumpers... you need to read the manual for that. Do you have the owner's manual? If not, you will need to spend some time on the Google machine to look it up.
 
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grommile

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Nov 24, 2019
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Looking at the photo, it's definitely not a lithium battery.

It's a three-cell NiCd pack (rated 3.6V). Depending on how fussy the circuit that draws from it is, a simple set of three AAs might not be a suitable replacement.
 
May 22, 2019
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You’re right. 3 alkaline cells would not work. That circuit would try to charge them and blow them up.

it might be possible to find a matching pack for that spot. Otherwise, I’d look for a AAA holder and some low mAh NiCd or NiMh cells.
 
May 22, 2019
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Here is a similar battery on Amazon. There are several similar shapes and sizes; the key thing to look for is a 3.6v nickel-based (NiMh or NiCd) battery of the right size to fit that spot on the board.

You do want to get *close* on the capacity rating (mAh), since some chargers may shut down too soon when attempting to charge the battery if the battery's capacity is too high. Likewise, if it's too low, the charger might overcharge and damage the cells. However, NiCd chargers at the time were infamous for "trickle charging" battery packs, and would push a few milliamps through all the time to keep a battery pack topped off.

 

Grumgi

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Jan 23, 2020
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Same voltage it looks like, and the mAH is only slightly higher than what's rated on the battery (80 vs 60). However, I'm thinking of replacing the thing with another nicd battery as opposed to the nimh one due to price. As for charging, how would I even accomplish that in the first place?
 
May 22, 2019
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If you can find the same pack as the original, yes - I'd definitely go for that, first.

I've been working under the assumption that NiCd packs are unavailable, since when I search for VARTA 3.6v batteries, I find nothing but NiMh packs. The charging modes of NiCd and NiMh are similar enough that you can usually interchange them, and 80 vs 60mAh should not make a difference (going from 60 to 600mAh... that would be a problem.)
 

grommile

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Nov 24, 2019
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Northampton, UK
The EU has banned the manufacture of general-purpose NiCd batteries, which is why VARTA (a German company) doesn't make them any more. (There are two exemptions from the EU ban on NiCd batteries: emergency lighting/alarms, and medical equipment.)
 

Grumgi

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Jan 23, 2020
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I'm not surprised nicd batteries have been banned in certain portions of the world. As I recall, cadmium is not a particularly healthy substance to work with.
Also, it turns out the 'nicd' battery I was looking at was actually nimh, I just misread it. It is however, 60mAH, but we're dealing with mAH levels with a difference of 20, so it doesn't really matter.
This is the listing I had in mind, by the way
It's from China though, with quality control most likely being suspect at best. Is it work saving the 10 bucks or nah?