All the xt mobos I had except the Huyndai one had normal AT PSU power plugs and worked fine with AT PSUs ... so 99% you are OK.
Just to be sure post a pic/model though

I am using a regular AT PS with a XT motherboard. Beware, the connector is not 100% the same as the AT one. You can get it in but it may require a bit of coercing (the pins are round not rectangular in section, and the plastic part of the connector doesn't fit exactly the 2 plugs).

keropi wrote:

All the xt mobos I had except the Huyndai one had normal AT PSU power plugs and worked fine with AT PSUs ... so 99% you are OK.
Just to be sure post a pic/model though

I've posted some pics of the two XT motherboards that I recently acquired.

The first one has an 8088-2 CPU which, according to some quick searches on Google, is the 8 MHz CPU, paired with an 8087 math-coprocessor.
The second one is a later model which has the NEC V20 CPU (this one, according to the manual, is the 12 MHz version).
Both has the older style power connectors - isn't there perhaps an XT to AT style adaptor that one can get?

I also acquired two controller cards with batteries on them.
I haven't researched this much, but I think this could be some type of RTC that is on the controller cards?
You will notice in the first pic that the battery has leaked out and has, unfortunately, caused extensive damage around the area where the battery used to be soldered (ironically, there is no damage on the other side, not pictured, of this controller). You can see (in the close up) that the traces have started to "bulge" and that some of the capacitors were completely destroyed when coming into contact with the battery acid. It might be possible to repair.

The second one houses a coin cell battery (in this case the BR2325, which I think one can swop out for the similar CR2325?). This one is still in great condition, but it only has the standard serial, parallel & game port connectors.

The motherboard in your first picture is almost identical to the one I have. It works well with AT power supplies, with the caveats from my previous post (not a perfect fit mechanically).

I don't know anything about the motherboard in your second picture.

Batteries on ISA cards from that period were used for RTC and/or NVRAM, i.e. what came later to be called "CMOS" data area.

Yes a BR2325 can be safely replaced with a CR2325. It's still a non-rechargeable lithium primary cell, has the same dimensions, and over most of its life gives the same voltage. BR has a slightly different anode chemistry vs. the CR, and that makes it last somewhat longer than a CR, have a flatter discharge curve (i.e. less voltage drop as it ages) but also can only deliver smaller currents. In practice not a big difference. May mean however that you will have to replace the battery after 8 years instead of 10. 😀

> Why do these controllers (refer my 2nd post) have batteries?

The MM58167 is a prehistoric RTC chip.

You can use AT PSU's just fine with those boards, in fact you can even use ATX provided you use one of those ATX to AT adapters. ATX power supplies up to V1.3 still have -5V.

Welcome to the world of XT's. Very challenging world, but you'll feel special after you finish the build. A Turbo XT will make you able to cover early to late 1980's period gaming pretty well, with only 1988, 1989 games starting to ask for a 286. Still a 12MHz V20 can compete with a slow 6MHz 286, like the IBM 5170.

h-a-l-9000 wrote:

The MM58167 is a prehistoric RTC chip.

It is quite a dinossaur indeed. I started myself to use a Dallas DS1216E RTC. Had to tear the thing open and disconnect the internal battery and then solder and connecta CR2032. Works great!

carlostex wrote:

h-a-l-9000 wrote:

The MM58167 is a prehistoric RTC chip.

It is quite a dinossaur indeed. I started myself to use a Dallas DS1216E RTC. Had to tear the thing open and disconnect the internal battery and then solder and connecta CR2032. Works great!

Would either of these two controller cards (provided I can get the first one working again) be of any use in an XT based PC that (in most cases) did not have a RTC?
If so, is it simply a matter of plugging in the controller card and setting the date & time?
How and/or where would one set the date and time so that it keeps track? Via DOS' own DATE and TIME commands?

An appropriate program to set/get the RTC time may be found here, depending on your specific model: http://www.minuszerodegrees.net/rtc.htm

VileRancour wrote:

An appropriate program to set/get the RTC time may be found here, depending on your specific model: http://www.minuszerodegrees.net/rtc.htm

Thank you. I think I found the programs for the one with the coin cell battery (appears to be a DFI DIO-200X).
Will dig a bit more for the other one.

Regarding the first motherboard, I have a lengthy thread discussing mine here: http://www.vcfed.org/forum/showthread.php?484 … ebay-components (I find myself referencing that thread a lot lately, seems that there are quite a few of these floating around). It's a good motherboard, and as you see from the thread above I ended up putting those empty BIOS sockets to good use. Towards the end of the thread I uploaded the scanned manual for the motherboard as well.

stamasd wrote:

Regarding the first motherboard, I have a lengthy thread discussing mine here: http://www.vcfed.org/forum/showthread.php?484 … ebay-components (I find myself referencing that thread a lot lately, seems that there are quite a few of these floating around). It's a good motherboard, and as you see from the thread above I ended up putting those empty BIOS sockets to good use. Towards the end of the thread I uploaded the scanned manual for the motherboard as well.

Excellent and thank you for the link. I'm going to study this a bit more.