Omarkoman wrote on 2024-08-16, 05:30:

Is it possible to disable the onboard VGA card and use a separate ISA card? I got myself a Realtek TVGA 9000 ISA card which I would like to use.

Just install the card and see what happens.
It's common that BIOS tries to use the card first, and only enables onboard video if no card is found.

thanks, will give it a try. The onboard video only has 256kb so lets see what happens.

next question, the CPU is Siemens SAB80286-12-N and its not socketed but soldered onto the motherboard, see these two photos :

https://i.postimg.cc/65Hq2kBq/retro-pc-pc286m … 199090550-1.jpg

https://i.postimg.cc/jSL5zMjX/retro-pc-pc286m … 199090553-1.jpg

how can I find out if I can upgrade the CPU to higher ? eg the Siemens SAB80286-16-N CPU 16-bit 286 Processor 16MHz

https://www.ebay.com.au/itm/392633246436

they are very cheap and I wouldnt mind extra speed.

I also found these 25Mhz ones from Harris:

https://www.ebay.com.au/itm/392380447376

what other parts would I need to upgrade ? would I need to upgrade the FPU / coprocessor as well ?

A 286 is not positioned to take advantage of any SVGA features, so you may as well stick with the onboard VGA.

As long as it holds settings and keeps the time (as opposed to freezing in place) when powered off overnight, the battery is good enough.

To go from 12 MHz to 16 MHz, the entire chipset has to be able to handle 16 MHz. It may or may not be ready to do so. A lot of those old chipsets are stamped as 16 MHz, 20 MHz, or 25 MHz if they are so capable.

Re vga, i get it and i dont want svga just best image quality and speed for dos games, would have thought fast isa vga card would help.

As for the cpu upgrade, what other parts of the motherboard would need to support faster cpu?

and also, what is the best way to add a CD drive ? would the onboard IDE controller accept any IDE drive or do I need to either get an ISA controller or use a soundcard with controller ?

Adding a CDROM to a 286 can get complicated. They really were not designed for it yet but it is possible. No the onboard controller and bios will not generally support an IDE CDROM.
Back then SCSI or proprietary Sony, Mitsumi, LMSI, etc were the only ways as IDE cdroms were not a thing yet. What CDROM are you thinking of adding ? Just curious......

Ok thats what I thought thanks.

I am planning to use SB Pro 2.0 CT1600 with this 286 which has a panasonic/matsushita IDE controller on it so need to look for one of these I guess.

From what I can see so far they are rare and expensive but so is the overall 286 build so I dont mind.

last option is to add an ISA controller like Goldstar Prime but I am trying to limit additional cards in the PC. I assume if I go down this path I can just use any IDE optical drive.

Theoretically an IDE CD-ROM will work, it just won't be period-correct. And what will you do with the 5 1/4" floppy drive, then?

its ok, doesnt have to be 100% age correct. The HDD in the machine is already not age correct as its 853MB. As long as I can find an optical drive from the 90s, I am ok with that. Just a reader, not burner of course.

re: floppy drive - I wont be using it in this build. I barely have any 5.14" floppies ... lots of 3.5"

but yea, I'd rather find a drive for the CT1600

jakethompson1 wrote on 2024-08-21, 02:06:

A 286 is not positioned to take advantage of any SVGA features, so you may as well stick with the onboard VGA.

Maybe true, but that's not what I remember. To my knowledge, 800x600 16c works acceptable with all VGA compatible cards that have 256 KB.
It also works on an 80286 system. Or an NEC V20/V30/80186. Not sure of the weak 8088/8086, though.

With 256KB of video RAM, the 640x400 resolution works in 256 colours, too, but is not always being supported on all SVGA chips.

The Windows 3.1 "Super VGA" driver works in Standard-Mode, the 256c drivers supplied with WfW 3.11 do not.
Geoworks Ensemble 2.0 supports Super VGA, as well and needs no special 386 support as far as I know. Could be wrong, though.

SkyGlobe 3.6 for DOS supports 800x600 16c mode, too, by invoking it with "SkyGlobe S".
AutoSketch v3 works on my 286 in SVGA, as well. The SVADI driver uses VBE 1.x to provide resolutions up to 1280x1024.

Edit: That being said, in terms of video games, it might be still logical to replace the internal VGA by an external VGA card.
That's because 286 era SVGA titles do expect a specific VGA chip.:

I remember the Tseng ET4000 is being supported by the MS Flight Simulator 4/5 and the Legend Entertainment games,
while the Paradise PVGA (and V7 VEGA) is being supported by Wonderland by Magnetic Scrolls (and probably other Magnetic Window titles).

The Paradise PVGA's 800x600 16c mode was sometimes being copied/supported by other cards.

Horun wrote on 2024-08-21, 03:31:

Adding a CDROM to a 286 can get complicated. They really were not designed for it yet but it is possible. No the onboard controller and bios will not generally support an IDE CDROM.
Back then SCSI or proprietary Sony, Mitsumi, LMSI, etc were the only ways as IDE cdroms were not a thing yet. What CDROM are you thinking of adding ? Just curious......

I've used an SCSI drive in my 12 MHz 286 PC circa 1994/1995, that's all I can say.
It was connected to my Pro Audio Spectrum 16, which had a Trantor controller, which in turn was way below the 286's capabilities.

The SB16 CT1770 had an SCSI interface, as well or so I heard.

jakethompson1 wrote on 2024-08-21, 04:22:

Theoretically an IDE CD-ROM will work, it just won't be period-correct. And what will you do with the 5 1/4" floppy drive, then?

Interesting. How about Amiga users then ? Were they period-correct when they added 68020 to 68060 CPU accelerators in ~1993 to an Amiga 2000 released in 1987 ?
To my understanding, a CD-ROM drive was a very important piece of equipment way back in the 90s. To all computer users, no matter the platform.

Even owners of PC/XT systems, if they wanted to keep up with society.
If they were still using their dinosaur on a daily base, I wonder if they didn't consider buying a CD-ROM drive for parallel port.
I had one, at one point. It was made by Freecom, I think. It could use nibble mode, even.

Edit: Pictures added.

Here's what the oemsetup.inf for my OAK VGA card says about 286 support (OAK OTI-067).

; ; OEMSETUP.INF file for MS Windows 3.1 display drivers ; OAK TECHNOLOGY, Inc. Copyright (C) 1992 ; [disks] 1 =. ,"Microsof […]
Show full quote

;
; OEMSETUP.INF file for MS Windows 3.1 display drivers
; OAK TECHNOLOGY, Inc. Copyright (C) 1992
;
[disks]
1 =. ,"Microsoft Windows 3.1 Disk #1",disk1
2 =. ,"Microsoft Windows 3.1 Disk #2",disk2
3 =. ,"Microsoft Windows 3.1 Disk #3",disk3
4 =. ,"Microsoft Windows 3.1 Disk #4",disk4
5 =. ,"Microsoft Windows 3.1 Disk #5",disk5
6 =. ,"Microsoft Windows 3.1 Disk #6",disk6

[oemdisks]
O =. ,"OAK TECHNOLOGY WINDOWS 3.1 DRIVER DISK",disko

[display]
vga800 = o:vga800.drv, "OAK VGA 800x600 16 colors", "100,96,96", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
vga768nl = o:vga768nl.drv, "OAK VGA 768x1024 16 colors ( 8-bit)", "100,120,120", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
vga768l = o:vga768l.drv, "OAK VGA 768x1024 16 colors (16-bit)", "100,120,120", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
vga1knl = o:vga1knl.drv, "OAK VGA 1024x768 16 colors ( 8-bit)", "100,120,120", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
vga1kl = o:vga1kl.drv, "OAK VGA 1024x768 16 colors (16-bit)", "100,120,120", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
vga1280l = o:vga1280l.drv, "OAK VGA 1280x1024 16 colors (16-bit)", "100,120,120", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
oak8640l = o:oak8640l.drv, "OAK VGA 640x480 256 colors (286 or better)","100,96,96", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle
oak8800l = o:oak8800l.drv, "OAK VGA 800x600 256 colors (286 or better)","100,96,96", 2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vgadib.3gr,, 2:vgalogo.rle
oak81kl = o:oak81kl.drv, "OAK VGA 1024x768 256 colors (286 or better)","100,120,120",2:vgacolor.2gr, 2:vgalogo.lgo, o:vddokvga.386, 2:vga30.3gr,, 2:vgalogo.rle

Edit: There's one thing I've forgot to mention. The 12 MHz 80286 was part of the MPC specification (multimedia PC), version 1.0.
It was quickly being replaced by an 16 Mhz 386SX in the revised MPC 1 specification, but it was there originally.

That was before Windows 3.1, back in the day when Windows 3.0 MME was still important to multimedia PCs.
It's being mentioned in an episode of Computer Chronicles, I'm not making things up.
https://youtu.be/e--_r8L_KxU?t=1473

Edit: New link, the old is now private.
https://youtu.be/SyTiOCqfH8I?t=1482

"Eleven hardware manufacturers have agreed to use a common logo on their computers
to indicate the PCs meet a minimum standard for multimedia applications.
The new MPC logo will mean the computer systems include at least a 286 processor,
2 megabytes of memory, a 30 megabyte hard drive, a CD-ROM drive and a VGA card.
Manufacturers intending to use this new MPC logo include heavyweights like AT&T, Tandy and Zenith."

Another multimedia "PC" that used the 80286 processor was the Tandy VIS set-top box.
https://en.wikipedia.org/wiki/Tandy_Video_Information_System

I know that this barely qualifies, but it shows that the 80286 wasn't as poor as some may think.
It lacked virtual memory with paging, which was important in early 90s because of the RAM shortage back in the day.
That made the 386SX so appealing over the 286. It allowed HDD space to be used to compensate for RAM shortage.
And to run Windows 3.1 in 386 Enhanced-Mode, of course, which relied on V86 and paging.

Omarkoman wrote on 2024-08-21, 03:15:

and also, what is the best way to add a CD drive ? would the onboard IDE controller accept any IDE drive or do I need to either get an ISA controller or use a soundcard with controller ?

You'd need a ISA controller or sound card with built-in controller. I've done this on a 286. It wasn't difficult, just a matter of getting an ISA controller with matching CD-ROM.

Typically early CD-ROM controllers were proprietary since this was before the IDE standard. This is why older sound cards often had multiple CD-ROM connectors for different manufacturers' CD-ROM drivers.

Omarkoman wrote on 2024-08-21, 02:24:

As for the cpu upgrade, what other parts of the motherboard would need to support faster cpu?

Clock speed on older systems is typically tied to the crystal oscillator. Overclocking a 286 would involve removing and replacing the crystal.

As was mentioned, this will effect other components besides the CPU likely including memory chips and possibly the ISA bus as well.

Unless you know exactly what you're doing, I wouldn't recommend trying to overclock a 286. If you want a faster 286, the better option would be finding a board designed for faster speeds.

Shponglefan wrote on 2024-08-21, 12:33:

Omarkoman wrote on 2024-08-21, 03:15:

and also, what is the best way to add a CD drive ? would the onboard IDE controller accept any IDE drive or do I need to either get an ISA controller or use a soundcard with controller ?

You'd need a ISA controller or sound card with built-in controller. I've done this on a 286. It wasn't difficult, just a matter of getting an ISA controller with matching CD-ROM.

Typically early CD-ROM controllers were proprietary since this was before the IDE standard. This is why older sound cards often had multiple CD-ROM connectors for different manufacturers' CD-ROM drivers.

The early Sound Blaster 16 models, such as the CT1740 do have an 40pin IDE/ATAPI connector..
These cards can be configured via jumpers, still.

SB Pro clones or later SB16 models from the 27xx series might be half-Plug&Play still, not sure.

Plug&Play utilities can be 386-specfic, because they may use 386 opcodes.
In such a case EMU386 can help to get these "drivers" to run.

PS: About the proprietary thing, yes that was how it was in the 386/486 heyday.
Except for SCSI, which had been standard for a long time. Most Macintosh systems had used it for good reason.

ATAPI popped up circa 1994, about same time OS/2 Warp 3 hit the market (they were a few months apart form each other).
Warp 3 still lacked a lot of drivers, though. Warp 4 had drivers for hardware we now think "is normal", such as IDE CD-ROM drives.

For OS/2 1.3, SCSI is an option, too. That's relevant to 286 users running OS/2, maybe..
There are two or three drivers around for common SCSI controllers.

Edit: On a 286/386/486 system it's best to use two separate IDE channels, one for each device.
The HDD uses primary master (IDE port already in use) and the CD-ROM uses secondary master (IDE port on sound card or extra CD-ROM card).
Attaching both the HDD and CD-ROM to one cable is a bad idea. Old HDDs and modern IDE CD-ROMs don't like to share (generally speaking).

Edit: An please use old-style 40 conductor cables, not 80 conductor cables. Please do it, at least for testing.
The 80 conductor cable have on data pin on ground, for cable detection.
This may cause unnecessary trouble.