What voltage was the old Varta ? Many of the old 286, 386 used a 4.5v external if the 3.7v Varta was removed. The CR2032 may not be supplying enough voltage.....

Horun wrote on 2021-09-11, 16:31:

What voltage was the old Varta ? Many of the old 286, 386 used a 4.5v external if the 3.7v Varta was removed. The CR2032 may not be supplying enough voltage.....

The CR2032 was already installed when I got the board, so I don't know the previous voltage. My next best option is to rig up an external battery at a 4.5v. I have battery case and just need to connect the lead to it. I can also just set the time with MTCP on startup as well as I have 3C509 ISA network card installed. Lastly, I wonder if 3.6v coin cell battery would provide enough voltage to work?

I would try the external 4.5v first, that would rule out a board issue if it works. A rare few old boards had a 4.5v rechargeable not the 3.7v. Trying the 4.5v external will help find out as those boards needed 6v external (more diodes from the external pins to actual cmos battery traces). A 3.6v coin cell might work, is closer to the original typical 3.7v than a 3v 2032 but would still try the 4.5v external first....

Horun wrote on 2021-09-11, 16:51:

I would try the external 4.5v first, that would rule out a board issue if it works. A rare few old boards had a 4.5v rechargeable not the 3.7v. Trying the 4.5v external will help find out as those boards needed 6v external (more diodes from the external pins to actual cmos battery traces). A 3.6v coin cell might work, is closer to the original typical 3.7v than a 3v 2032 but would still try the 4.5v external first....

I did test RTC using Checkit and it tested Ok. I suspect it is too low a voltage using a CR2032 at this point.

If it had mTCPs NTP application running from the autoexec.bat file on start up I wouldn't worry about it.

Caluser2000 wrote on 2021-09-11, 19:11:

If it had mTCPs NTP application running from the autoexec.bat file on start up I wouldn't worry about it.

I added MTCP to my AUTOEXEC as suggested and it works just fine. I load the 3C5X9PD packet driver, set the time and then unload the packet driver from memory. This turns out to be a quick and easy solution that does take up any memory. I have separate batch file load networking if need it to transfer files.

jasa1063 wrote on 2021-09-11, 22:20:

Caluser2000 wrote on 2021-09-11, 19:11:

If it had mTCPs NTP application running from the autoexec.bat file on start up I wouldn't worry about it.

I added MTCP to my AUTOEXEC as suggested and it works just fine. I load the 3C5X9PD packet driver, set the time and then unload the packet driver from memory. This turns out to be a quick and easy solution that does take up any memory. I have separate batch file load networking if need it to transfer files.

Good on you...😉

Seems the 32,768Hz oscillator needs more than 3V to run.
Have seen this quite often.

These boards with the barrel battery were supposed to be regularly turned on, charging the battery.
And the NiCd characteristics is that the voltage only drops sharply when near to empty.
So, back then there was no perceived actual need to make sure that the oscillator runs at less than 3.6V.

In this case a 4.5V battery actually seems the only practical solution.

retardware wrote on 2021-09-11, 22:41:

Seems the 32,768Hz oscillator needs more than 3V to run. Have seen this quite often. […]
Show full quote

Seems the 32,768Hz oscillator needs more than 3V to run.
Have seen this quite often.

These boards with the barrel battery were supposed to be regularly turned on, charging the battery.
And the NiCd characteristics is that the voltage only drops sharply when near to empty.
So, back then there was no perceived actual need to make sure that the oscillator runs at less than 3.6V.

In this case a 4.5V battery actually seems the only practical solution.

I did a little more research and there are LIR 2032/H batteries that are 3.6/3.7 volt. They are also rechargeable. I wonder if that could be a workable solutions as well?

jasa1063 wrote on 2021-09-11, 23:21:

I did a little more research and there are LIR 2032/H batteries that are 3.6/3.7 volt. They are also rechargeable. I wonder if that could be a workable solutions as well?

Only use NiCD batteries!
But this only viable if you use (and thus recharge the battery) the computer at least a few hours daily.
Otherwise the next spill is pre-programmed.

Never ever use lithium rechargeable batteries in circuits made for NiCD!
You certainly do not want a fire/explosion hazard!

Edit: I tried, but somehow I failed to set the font size of the bold text above to "Large". How can I do this?

I dunno, I guess it does it automatically if you type louder

retardware wrote on 2021-09-11, 23:45:

Only use NiCD batteries! But this only viable if you use (and thus recharge the battery) the computer at least a few hours daily […]
Show full quote

jasa1063 wrote on 2021-09-11, 23:21:

I did a little more research and there are LIR 2032/H batteries that are 3.6/3.7 volt. They are also rechargeable. I wonder if that could be a workable solutions as well?

Only use NiCD batteries!
But this only viable if you use (and thus recharge the battery) the computer at least a few hours daily.
Otherwise the next spill is pre-programmed.

Never ever use lithium rechargeable batteries in circuits made for NiCD!
You certainly do not want a fire/explosion hazard!

Edit: I tried, but somehow I failed to set the font size of the bold text above to "Large". How can I do this?

Thanks for that info. I was not aware of that with rechargable Lithium Ion batteries. The 4.5v external battery is going to be the solution then or just run MTCP in the AUTOEXEC.BAT.

BitWrangler wrote on 2021-09-11, 23:59:

I dunno, I guess it does it automatically if you type louder

Edit: go to full editor, use the AA dropdown at top right and if bold is breaking it, try putting bold outside size tags.

Edit2: Wrong lever Cronk! that wasn't an edit 🤣

BitWrangler wrote on 2021-09-11, 23:59:

I dunno, I guess it does it automatically if you type louder

Ahh, thank you for teaching me how to type REALLY LOUD 😀

Ouch...

Forums software wrote:

You may only use fonts up to size 150.

jasa1063 wrote on 2021-09-12, 00:06:

...just run MTCP in the AUTOEXEC.BAT.

Yes, MTCP seems to be an economic solution.
The alkaline batteries tend to last not very long, and this is a real hassle.
Because, the oscillator in many of these rechargeable-battery-designs seems not be designed for low power usage/sustained battery operation.

Caluser2000 wrote on 2021-09-11, 19:11:

If it had mTCPs NTP application running from the autoexec.bat file on start up I wouldn't worry about it.

You're maybe too young to know, but there also were external radio receivers for DCF-77 time signal that could be attached on a serial port.
https://www.youtube.com/watch?v=vzUTV66A_V8

This was the professional way of keeping devices in sync. 😀

Edit: I forgot your location, silly me. In that land far away from civilized Europe, there's likely no reception of it. 😉

Edit: JJY seems to be the last one that can be received.
Anyway, the Japanese have a good technology, at least.
https://en.wikipedia.org/wiki/JJY
https://www.geekzone.co.nz/forums.asp?forumid … &topicid=181404

US had time signals on Low radio frequencies, thought I heard they were shutting them down though. I'm thinking naval one at Annapolis right now, fergetted... wikipedia should know...

Edit: Okay, that's the one that's still going https://en.wikipedia.org/wiki/WWVB searching Forrest Mims or Steve Ciarcia and WWVB might get you circuits to adapt.

Jo22 wrote on 2021-09-12, 02:13:

You're maybe too young to know, but there also were external radio receivers for DCF-77 time signal that could be attached on a […]
Show full quote

Caluser2000 wrote on 2021-09-11, 19:11:

If it had mTCPs NTP application running from the autoexec.bat file on start up I wouldn't worry about it.

You're maybe too young to know, but there also were external radio receivers for DCF-77 time signal that could be attached on a serial port.
https://www.youtube.com/watch?v=vzUTV66A_V8

This was the professional way of keeping devices in sync. 😀

Edit: I forgot your location, silly me. In that land far away from civilized Europe, there's likely no reception of it. 😉

Edit: JJY seems to be the last one that can be received.
Anyway, the Japanese have a good technology, at least.
https://en.wikipedia.org/wiki/JJY
https://www.geekzone.co.nz/forums.asp?forumid … &topicid=181404

I bet I'm older than you.

Edit:Nothing to add or alter.....

🤣 thanks, you all gave me a good laugh !

I removed the coin cell battery and rigged up an external 4.5v battery today. The time is now updating normally with the computer turned off. I am just relieved to know that there is no damage to the motherboard as far as the RTC is concerned.