That is earlier than it’s design would suggest.

I had a 286-25 with a paiR of 72pin simm sockets and a riser card for ISA, onboard VGA

Most of those small boards I’ve encountered were 1992+

Gotta wonder if a PCCHIPS SHART chipset bios from a 386sx would work?

https://theretroweb.com/motherboards/s/jc-inf … ration-jcs286-s
page added. now off to hunt for a SCAT MR. BIOS....

Wait...PCCHIPS had a "SHART" chipset? As in shit + fart = shart? You know, like when you want to fart but you end up crapping your pants.

SCAT isn't much better. Scat means shit, doesn't it?

The big bundle is here: http://vogonsdrivers.com/getfile.php?fileid=1971&menustate=0

Here are the versions:
V032B300 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO
V032B304 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO x032B300 (711)(TL-)
V032B305 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO x032B300 (711)(TL+)

TL is for the "Turbo Light"

Anonymous Coward wrote on 2023-01-26, 15:42:

SCAT isn't much better. Scat means shit, doesn't it?

Depends on context, of course, but it might mean shit. In this context, SCAT is the acronym for "Single Chip AT", though.

It seems to me that C&T was intentionally using acronyms that spelled words. The NEAT acronym was a clever one, but what the hell was up with SCAT? Was somebody at C&T really into scat? How did anyone in their marketing department think that was a good idea?

I'm still waiting to learn more about the "SHART" chipset. It's definitely a good name for a PCchips product. I searched and couldn't find anything. Was it just an auto-correct phone typo, or is it a real thing? Is it an acronym, and if so what does it stand for? Shitty Half-Assed Relabeled Technology?

douglar wrote on 2023-01-26, 18:58:

The big bundle is here: http://vogonsdrivers.com/getfile.php?fileid=1971&menustate=0 […]
Show full quote

The big bundle is here: http://vogonsdrivers.com/getfile.php?fileid=1971&menustate=0

Here are the versions:
V032B300 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO
V032B304 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO x032B300 (711)(TL-)
V032B305 Chips & Technologies SCAT-SX 82C386 "SCAT-SX", with 82C711 combo-IO x032B300 (711)(TL+)

TL is for the "Turbo Light"

But would that work with the 82C235 on the board? Part numbers are certainly different.

jakethompson1 wrote on 2022-06-07, 01:58:

You may have seen that there are a bunch of these on eBay. They come with some kind of router firmware instead of a BIOS and don […]
Show full quote

You may have seen that there are a bunch of these on eBay. They come with some kind of router firmware instead of a BIOS and don't work out of the box.

1. I replaced the BIOS chip with one with a Biostar MB-1212C BIOS. It seems to work, although the turbo header on the board doesn't seem to work (possible incompatibility with keyboard controller?) however Ctrl Alt + and Ctrl Alt - do work. With the GW-286CT BIOS access to an IDE hard drive did not work reliably, so it was not programming something correctly with the chipset.

2. It has an odd setup for memory. It ships with 1MB in eight 20-pin DIP chips plus parity. Because the BIOS is an 8-bit chip and not 16-bit with odd/even chips you really want shadowing on which leaves you with only 640K. But there is also an unpopulated header for a 72-pin SIMM socket. After soldering on a socket, it indeed works with an 8MB SIMM (and only 8MB--4MB will not work). This matches the markings on the board. Maybe you could upgrade to 4MB with 512Kx4 DRAMs (are there such a thing?) but the SIMM socket+8MB SIMM is certainly cheaper if you can solder.

Ships at 12 1/2MHz and a 12 1/2MHz 286 CPU, but the chipset has markings on it for 16 MHz. So I bet with a crystal change it could be upgraded.

Thank you for posting this. I bought one of these. It hasn't arrived yet, but I've been studying the RAM info text by looking at photos in the listing and on TRW. I was wondering if anyone has tried soldering a SIMM socket to it and you answered my question, so now of course I want to try this. Finding DRAM in DIP to increase the memory on this is very difficult, so using a SIMM sounds good. I assume a standard 2Mx36 FPM module?

Did you ever get IDE drives to work reliably? It seems like this shouldn't be an issue with something simple like the IDE interface, but then again what do I know. A MR BIOS would be nice, but I'm not so sure one exists.

eesz34 wrote on 2023-02-07, 14:01:

Thank you for posting this. I bought one of these. It hasn't arrived yet, but I've been studying the RAM info text by looking at photos in the listing and on TRW. I was wondering if anyone has tried soldering a SIMM socket to it and you answered my question, so now of course I want to try this. Finding DRAM in DIP to increase the memory on this is very difficult, so using a SIMM sounds good. I assume a standard 2Mx36 FPM module?

Did you ever get IDE drives to work reliably? It seems like this shouldn't be an issue with something simple like the IDE interface, but then again what do I know. A MR BIOS would be nice, but I'm not so sure one exists.

Yeah, I think I used a 70ns, 8MB FPM SIMM.

IDE drives work with the MB-1212C BIOS. I believe the issue is that many late-1980s BIOSes have a race condition when used with IDE drives. The way the interface works is the BIOS is supposed to tell the drive information about the starting sector, and the number of sectors to read. Every time the drive has another sector ready, it generates an interrupt (IRQ). The BIOS is supposed to acknowledge the interrupt by reading from the status register, and then read in one sector, and go back to what it was doing. Some of these ancient BIOSes do it in a different order: they read in the sector, then read the status register to make sure there was no error. With fast IDE drives, the the next sector might already be ready after receiving the last two bytes of the previous sector, and the drive has already generated another interrupt, but the BIOS loses it by because it's too slow relative to the drive. Given that this is fixed even in vintage (1989ish looking at the AMI Programmer's Guide book) BIOSes, I suspect even period-correct hard drives got too fast pretty quickly.

jakethompson1 wrote on 2023-02-08, 22:55:

eesz34 wrote on 2023-02-07, 14:01:

Thank you for posting this. I bought one of these. It hasn't arrived yet, but I've been studying the RAM info text by looking at photos in the listing and on TRW. I was wondering if anyone has tried soldering a SIMM socket to it and you answered my question, so now of course I want to try this. Finding DRAM in DIP to increase the memory on this is very difficult, so using a SIMM sounds good. I assume a standard 2Mx36 FPM module?

Did you ever get IDE drives to work reliably? It seems like this shouldn't be an issue with something simple like the IDE interface, but then again what do I know. A MR BIOS would be nice, but I'm not so sure one exists.

Yeah, I think I used a 70ns, 8MB FPM SIMM.

IDE drives work with the MB-1212C BIOS. I believe the issue is that many late-1980s BIOSes have a race condition when used with IDE drives. The way the interface works is the BIOS is supposed to tell the drive information about the starting sector, and the number of sectors to read. Every time the drive has another sector ready, it generates an interrupt (IRQ). The BIOS is supposed to acknowledge the interrupt by reading from the status register, and then read in one sector, and go back to what it was doing. Some of these ancient BIOSes do it in a different order: they read in the sector, then read the status register to make sure there was no error. With fast IDE drives, the the next sector might already be ready after receiving the last two bytes of the previous sector, and the drive has already generated another interrupt, but the BIOS loses it by because it's too slow relative to the drive. Given that this is fixed even in vintage (1989ish looking at the AMI Programmer's Guide book) BIOSes, I suspect even period-correct hard drives got too fast pretty quickly.

Looking back at your original post, I now see that you said it worked with MB-1212C, but not the other. So I have that clear now. Incidentally one of the eBay buyer's feedback was they used "GW-286CT GEAR" BIOS which is available in a post here on Vogons. Given only 3 had been sold by that time it's probably someone on this board. I'll have to try both.

And thank you for your explanation about the BIOS. I had no idea that was an issue.

I always assumed "CHIPS" AKA "Chips & Technologies" and "PC-Chips" were two different companies.
Was it one and the same after all??

Absolutely not the same company. They're pretty much polar opposites.
I think that what might add to the confusion is that sometimes a board with a PCchips chipset might also use a "CHIPS" 206 system controller. The 206 seems to be somewhat interchangeable and I guess you can mix brands and it doesn't matter.

Anonymous Coward wrote on 2023-02-09, 14:10:

The 206 seems to be somewhat interchangeable and I guess you can mix brands and it doesn't matter.

It's not just "somewhat interchangable", but the C&T 82c206 was an instant hit in the market and there are compatible clones by many far-east companies. The term got so common that some higher integrated ISA bridges like the SiS 497 is specified to contain "an 206 macrocell", which means that the transistor-level design of the 82c206 was pasted as a part into the logic design of that bridge. As long as the pinout matches (there are at least two common 206 pinouts), you can mix brands whatever you like.

jakethompson1 wrote on 2023-02-08, 22:55:

Yeah, I think I used a 70ns, 8MB FPM SIMM.

IDE drives work with the MB-1212C BIOS. I believe the issue is that many late-1980s BIOSes have a race condition when used with IDE drives. The way the interface works is the BIOS is supposed to tell the drive information about the starting sector, and the number of sectors to read. Every time the drive has another sector ready, it generates an interrupt (IRQ). The BIOS is supposed to acknowledge the interrupt by reading from the status register, and then read in one sector, and go back to what it was doing. Some of these ancient BIOSes do it in a different order: they read in the sector, then read the status register to make sure there was no error. With fast IDE drives, the the next sector might already be ready after receiving the last two bytes of the previous sector, and the drive has already generated another interrupt, but the BIOS loses it by because it's too slow relative to the drive. Given that this is fixed even in vintage (1989ish looking at the AMI Programmer's Guide book) BIOSes, I suspect even period-correct hard drives got too fast pretty quickly.

I got one of these and found the same as you with regard to the BIOS. So I'm also using the MB-1212C BIOS and it works great. Same turbo issue but it's minor. Also discovered the SIMM socket footprint was placed too close to the oscillator. I debated grinding some plastic off the socket, but decided to solder it in with uniform gap between the PCB and socket. Works great and 8MB in a 286, woohoo! Would never have had that back in the day!

BTW did you have any floppy access problems, namely that the disk change signal doesn't seem to work? This could be something else but I've never had this issue before on anything.

mkarcher wrote on 2023-02-09, 18:50:

Anonymous Coward wrote on 2023-02-09, 14:10:

The 206 seems to be somewhat interchangeable and I guess you can mix brands and it doesn't matter.

It's not just "somewhat interchangable", but the C&T 82c206 was an instant hit in the market and there are compatible clones by many far-east companies. The term got so common that some higher integrated ISA bridges like the SiS 497 is specified to contain "an 206 macrocell", which means that the transistor-level design of the 82c206 was pasted as a part into the logic design of that bridge. As long as the pinout matches (there are at least two common 206 pinouts), you can mix brands whatever you like.

if there are two different pinouts, I would say the phrase "somewhat interchangeable" fits the situation to a T

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.

It's a *LOT* nicer than the ones that were on TRW until now, and works nicely with this wonky board too, it seems (though I have not yet tested it with 8MB RAM - waiting for the sockets to get soldered on).

/Eirik

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 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.

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'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.

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.