ltning wrote on 2023-06-10, 21:51:

I didn't even try the switch. It's not something I use a lot 😀
I'll do that when I get the boards back.

I'll be installing a 4.something volt battery once I get around to measuring properly. The onboard battery seemed to be leak-free but I'm pretty sure it has no juice left.

So just a piece of advice about that NiCd on the JCS board....mine was also leak free, until about a day into powering it. Then it started leaking. My advice is take it off right now.

eesz34 wrote on 2023-06-11, 14:18:

I'm pretty sure the turbo switch doesn't work with MB-1212. That's the image I settled on and seem to remember trying this out and seeing no response. I also seem to remember the turbo LED would light when it was in normal speed, not turbo. Probably can be resolved by using the other power rail as the common.

Yeah, I'm the one who suggested MB-1212C above. It seemed ltning found a different version of MB-1212 though.

eesz34 wrote on 2023-06-11, 14:18:

I've been using 3 AA battery holders on multiple systems, including this one, and plug it into the header. The cool thing about those is even when the batteries are new, it's still under 5V total as I would imagine you don't want to go much over that. And, with batteries that are too low for other devices, like 1.1 or 1.2V, they still work as CMOS backup. As a bonus, it lasts *years*.

I get creative when mounting the battery holder. I don't trust double sided tape so I use screws or standoffs to mount somewhere but I don't modify the computer case.

I use those also, they're just bulky and it seems like others don't talk about them and instantly go to CR2032 without mentioning the voltage issue. 4.5V is what those Rayovac Computer Clock Batteries were. Someone took one apart and found it's like a 9-volt inside but split in half with two groups of three cells wired in parallel to last longer.

jakethompson1 wrote on 2023-06-11, 14:54:

Yeah, I'm the one who suggested MB-1212C above. It seemed ltning found a different version of MB-1212 though.

Doh, I'm not paying attention. I thought that was you as I typed the reply.

All I did so far was put it into PCem and I can see it's a C&T BIOS, not AMI like the MB-1212 I ended up using. The C&T BIOS didn't work with the CF card I had connected but I'm curious to try this out (unless someone beats me to it).

I just plugged that C&T BIOS into the JSC board after I got the 72pin socket soldered on, and it works as expected. However, neither turbo switch nor LED seem to work at all.

Currently got 3MB Extended and 4MB Expanded memory configured. And 0-ws and the works. Boots nicely from CF. I have a Promise DC200M with its own BIOS (so no XTIDE right now), but it does rely on the BIOS poking the "HDD" before the controller can take over, so that seems to work as prescribed.

Got it ethernet-networked, so up yours, Token Ring! ;)

eesz34 wrote on 2023-06-11, 18:05:

jakethompson1 wrote on 2023-06-11, 14:54:

Yeah, I'm the one who suggested MB-1212C above. It seemed ltning found a different version of MB-1212 though.

Doh, I'm not paying attention. I thought that was you as I typed the reply.

All I did so far was put it into PCem and I can see it's a C&T BIOS, not AMI like the MB-1212 I ended up using. The C&T BIOS didn't work with the CF card I had connected but I'm curious to try this out (unless someone beats me to it).

I see. A lot of ancient BIOSes have a bug where they don't work with IDE drives because upon receiving an IRQ14, they read a sector from the drive and then read the status register to clear the IRQ, instead of the other way around. The issue is that IDE drives are so fast that a second IRQ comes in between reading the last word of the sector and reading the status register, so an IRQ is lost. I forget whether that was the issue with the C&T BIOS (in which case XT-IDE BIOS would work around it) or if it was something deeper like the way it programmed the chipset was such that IDE wouldn't work regardless of the software used to access the drive.

Perhaps the hardware turbo switch never worked with these boards? I can't remember if it worked with the GW-286CT BIOS. Maybe the keyboard controller and not just the chipset is involved in the hardware turbo control.

jakethompson1 wrote on 2023-06-11, 18:26:

A lot of ancient BIOSes have a bug where they don't work with IDE drives because upon receiving an IRQ14, they read a sector from the drive and then read the status register to clear the IRQ, instead of the other way around.

This includes the original IBM 5170 AT BIOS as well the AMI BIOSes of that time. Possibly the formal definition of the IDE interface including such subtleties wasn't done when those BIOSes were written. And who would expect the drive to issue another IRQ within a couple of microseconds after transferring a sector 😉

jakethompson1 wrote on 2023-06-11, 18:26:

eesz34 wrote on 2023-06-11, 18:05:

jakethompson1 wrote on 2023-06-11, 14:54:

Yeah, I'm the one who suggested MB-1212C above. It seemed ltning found a different version of MB-1212 though.

Doh, I'm not paying attention. I thought that was you as I typed the reply.

All I did so far was put it into PCem and I can see it's a C&T BIOS, not AMI like the MB-1212 I ended up using. The C&T BIOS didn't work with the CF card I had connected but I'm curious to try this out (unless someone beats me to it).

I see. A lot of ancient BIOSes have a bug where they don't work with IDE drives because upon receiving an IRQ14, they read a sector from the drive and then read the status register to clear the IRQ, instead of the other way around. The issue is that IDE drives are so fast that a second IRQ comes in between reading the last word of the sector and reading the status register, so an IRQ is lost. I forget whether that was the issue with the C&T BIOS (in which case XT-IDE BIOS would work around it) or if it was something deeper like the way it programmed the chipset was such that IDE wouldn't work regardless of the software used to access the drive.

Perhaps the hardware turbo switch never worked with these boards? I can't remember if it worked with the GW-286CT BIOS. Maybe the keyboard controller and not just the chipset is involved in the hardware turbo control.

I re-read my reply and see it might have confused something. What I meant to say was I tried a C&T BIOS on this board at one time and the CF card didn't work. So, seeing that this "new" one is also a C&T BIOS makes me wonder if it's either the same, or if it'll have the same problem.

I don't recall if the turbo switch worked or not either.

ltning wrote on 2023-06-11, 18:10:

I just plugged that C&T BIOS into the JSC board after I got the 72pin socket soldered on, and it works as expected. However, neither turbo switch nor LED seem to work at all.

Currently got 3MB Extended and 4MB Expanded memory configured. And 0-ws and the works. Boots nicely from CF. I have a Promise DC200M with its own BIOS (so no XTIDE right now), but it does rely on the BIOS poking the "HDD" before the controller can take over, so that seems to work as prescribed.

Got it ethernet-networked, so up yours, Token Ring! 😉

Try ctrl-alt-minus or plus to switch between normal and turbo and see if the turbo LED works. It works on mine with an AMI BIOS, but the LED behavior is opposite of what you'd think.

So the C&T BIOS boots from CF....I wonder if it would boot using only the MB BIOS. In my experience, the C&T BIOS won't work with solid state drives.

What do you mean won't work with solid state? That's what I'm using .. Unless you mean something else than CF, like PATA-SSD?

ltning wrote on 2023-06-11, 20:39:

What do you mean won't work with solid state? That's what I'm using .. Unless you mean something else than CF, like PATA-SSD?

But aren't you using an option ROM for IDE support and not relying on the C&T alone?

jakethompson1 wrote on 2023-06-11, 20:56:

ltning wrote on 2023-06-11, 20:39:

What do you mean won't work with solid state? That's what I'm using .. Unless you mean something else than CF, like PATA-SSD?

But aren't you using an option ROM for IDE support and not relying on the C&T alone?

Ah sorry, I thought "everyone" used some kind of BIOS to get larger drives these days. I forgot that I'm chickening out on some aspects of retro :)
I have not tested a CF card without a BIOS. I can do that, I think I have a 64MB card that I should be able to test with. Just need to figure out its parameters..

Not sure I have the energy to do that today. It's been a bad enough weekend for science already :D

jakethompson1 wrote on 2023-06-11, 14:54:

I use those also, they're just bulky and it seems like others don't talk about them and instantly go to CR2032 without mentioning the voltage issue. 4.5V is what those Rayovac Computer Clock Batteries were. Someone took one apart and found it's like a 9-volt inside but split in half with two groups of three cells wired in parallel to last longer.

Or you could use a single AA holder and use those lithium 3.6V cells. I have two of them I got somewhere that are 31 years old, going by the date code. Still measures over 3.6V.

There's usually so much extra space in an old case the 3 AA holders are no issue. Even in my tiny Prolinea 3/25zs. Of course your situation could be different.

ltning wrote on 2023-06-11, 21:41:

Ah sorry, I thought "everyone" used some kind of BIOS to get larger drives these days. I forgot that I'm chickening out on some aspects of retro 😀
I have not tested a CF card without a BIOS. I can do that, I think I have a 64MB card that I should be able to test with. Just need to figure out its parameters..

Not sure I have the energy to do that today. It's been a bad enough weekend for science already 😁

I decided against using XT-IDE or what have you. My 4GB SSD seems to do fine in this 286 and my 386. I don't get to use beyond 500MB but what would I do with that extra space anyway 😀

jakethompson1 wrote on 2023-06-10, 21:48:

ltning wrote on 2023-06-10, 21:46:

I just received a couple of these boards too. And I have a MB-1212 BIOS that I couldn't find on TRW; I uploaded it there yesterday. Attached here if anyone wants to play.

Does the hardware turbo switch work with this BIOS?

Also, does anyone have a good CMOS battery solution with these boards? A CR2032 is enough to retain the settings, but not advance the date/time while the board is powered off.

I tried the turbo switch myself and no, shorting the header does nothing. Also the turbo LED output does nothing. ctrl-alt- minus and plus does change CPU speeds though. I tried the header with it already in both speeds, and still nothing. It also won't boot from IDE using the BIOS alone.

So yeah the BIOS looks cool because it's in color, but I'll stick with the AMI because it does everything better.

eesz34 wrote on 2023-06-13, 14:53:

So yeah the BIOS looks cool because it's in color, but I'll stick with the AMI because it does everything better.

Other than the turbo switch/LED, what does the other BIOS do better? One major advantage of the color BIOS is that it allows more granular setting of EMS memory size. In particular, it lets me set more than 3 MB for EMS (or was it >3MB extended?) - which is a big deal under e.g. DesqVIEW: The more EMS, the more sessions you can have with "reasonable" memory assigned to each.

/Eirik

ltning wrote on 2023-07-30, 19:05:

eesz34 wrote on 2023-06-13, 14:53:

So yeah the BIOS looks cool because it's in color, but I'll stick with the AMI because it does everything better.

Other than the turbo switch/LED, what does the other BIOS do better? One major advantage of the color BIOS is that it allows more granular setting of EMS memory size. In particular, it lets me set more than 3 MB for EMS (or was it >3MB extended?) - which is a big deal under e.g. DesqVIEW: The more EMS, the more sessions you can have with "reasonable" memory assigned to each.

/Eirik

I don't have comprehensive knowledge of the two (so maybe I shouldn't have said "everything better"), but the C&T BIOS won't boot from the flash-based IDE I've tried. In comparison the AMI will boot from IDE, even over 504MB although it won't use it beyond that. So yeah the EMS setting is a little lacking on the AMI but I rarely use it.

anyone get their board working at 16Mhz or 20Mhz?

anyone try the mr bios for 386sx scat or the generic 286 bios?

douglar wrote on 2023-12-14, 01:27:

anyone get their board working at 16Mhz or 20Mhz?

anyone try the mr bios for 386sx scat or the generic 286 bios?

I didn't bother trying to increase the clock frequency or either of the two BIOSs you mention, but I'd love a MR BIOS for this. I assumed a 386 BIOS won't work on a 286, and that the generic won't work because that's for MBs that don't have a chipset. I also assumed the SCAT chip has registers that the BIOS needs to set, and are present in the SCAT BIOS.

Nothing wrong with trying a different BIOS though! I'm not going to try boosting the clock though since that's riskier and I don't need it.

eesz34 wrote on 2023-12-15, 14:16:

Nothing wrong with trying a different BIOS though! I'm not going to try boosting the clock though since that's riskier and I don't need it.

MR Bios 1.65 should correctly support LBA drives, which would be nice to have.

Looks to me like that board might have a 10ns SRAM cache on it in the top right as pictured here: https://theretroweb.com/motherboards/s/jc-inf … ration-jcs286-s

Is that the case?

douglar wrote on 2023-12-15, 14:45:

MR Bios 1.65 should correctly support LBA drives, which would be nice to have. […]
Show full quote

eesz34 wrote on 2023-12-15, 14:16:

Nothing wrong with trying a different BIOS though! I'm not going to try boosting the clock though since that's riskier and I don't need it.

MR Bios 1.65 should correctly support LBA drives, which would be nice to have.

Looks to me like that board might have a 10ns SRAM cache on it in the top right as pictured here: https://theretroweb.com/motherboards/s/jc-inf … ration-jcs286-s

Is that the case?

That's 100ns ram