Robx66 wrote on 2023-04-05, 04:23:

Hi,

Just to show my 286 PC 😀
Monster !!

Raaawwwwwrrr. 😂

Robx66 wrote on 2023-04-05, 04:23:

12MHz with step down to 8MHz 1MB RAM increased from 640kB 170MB HDD Graphics card..... something with 256kB ram but will try to […]
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12MHz with step down to 8MHz
1MB RAM increased from 640kB
170MB HDD
Graphics card..... something with 256kB ram but will try to extend it to 512kB.

The main memory is more in need, maybe.
If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Extended Memory anymore.
It's then either Shadow Memory or Extended Memory.

That's one of the reasons why I have an aversion against 1 MB setups.
That being said, it's your PC, of course. You have the last say how to configure it, and that's fine. Each to his own. 🙂👍

Anyway, 512KB of VGA memory is no waste. Picture viewers and programs like Geoworks Ensemble 2.o (and up) can use SVGA and VBE.

For VBE, a DOS-based TSR might be needed.
And the correct DIP switch settings on the VGA card.

Re: OAK OTI-037c - 800x600 mode ?

If you encounter DOS programs with 386 instructions, EMU386 can help.

Re: Timeline of MS-DOS for NEC PC98 and more

As for the HDD.. Nice, a classic! 🙂
If you ever run out of storage, you can run DoubleSpace/DriveSpace.
Performance hit is marginal, I'be tried it on an XT, even.
In some circumstances, drive compression can even improve performance.

Robx66 wrote on 2023-04-05, 04:23:

Nice old machine. The guy who I bought it from said he bought it from the company he worked for, years ago when they were replacing all computers and it was used for CAD 🤣 !

Sure, I've ran AutoSketch 2 on an 286/12 in the past.
The diskettes included an x87 version of the software, too.
This AT clone is more than capable fot this task.

Add another 2MB of RAM and it can run AutoSketch for Windows 1.x, even.

Edit: The WD90C00 is compatible with PVGA1A drivers.
They can do 640x400 in 256c on Windows.
See Re: 286 USIT Athena PC

Jo22 wrote on 2023-04-05, 05:41:

The main memory is more in need, maybe. If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Exte […]
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The main memory is more in need, maybe.
If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Extended Memory anymore.
It's then either Shadow Memory or Extended Memory.

That's one of the reasons why I have an aversion against 1 MB setups.
That being said, it's your PC, of course. You have the last say how to configure it, and that's fine. Each to his own. 🙂👍

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

Robx66 wrote on 2023-04-05, 06:42:

Jo22 wrote on 2023-04-05, 05:41:

The main memory is more in need, maybe. If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Exte […]
Show full quote

The main memory is more in need, maybe.
If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Extended Memory anymore.
It's then either Shadow Memory or Extended Memory.

That's one of the reasons why I have an aversion against 1 MB setups.
That being said, it's your PC, of course. You have the last say how to configure it, and that's fine. Each to his own. 🙂👍

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

No no, I don't blame you. It wasn't meant as a complaint at all. 😅
I know those big old motherboards with their DIP/DIL RAM chips.. They have a nice "chipset" and an elegant layout, but no SIMM/SIPP sockets yet.

I just said that because I sometimes end up in an argument about period-correct RAM configurations.

That's because my ideas of an 286 often clash together with that of others.
The majority sees an 286 just as a fast XT, it seems. An oldie for playing Tetris or KingsQuest in Hercules/EGA.
By contrast, I grew up with a second-hand 286 PC in the 90s, that my father and me assembled/refurbished.

Long story short, we treated the 286 the same as a 386/486 at the time. Which it essentially was, except for the vintage CPU.. The motherboard was modern, had SVGA on-board (ATI VGA Wonder), along with a bus mouse port.

That means, we installed an 80 MB IDE HDD, 4x 1 MB SIMMs, a PAS16 soundcard+SCSI CD-ROM drive (both part of a multimedia upgrade kit; common at the time)..

Later, the PC got a Mustek handy scanner - a tiny ISA card served as an interface card.
Below the desktop was an HP Laserjet +.

By 90s definition, that 286 was a real multimedia PC, capable of running Windows 3.1x smoothly.
In fact, it did just about comply to the first version of the MPC Level 1 specification (286-12 CPU, the revised version had 386SX-16).

I've even did a bit of software development on that 286 PC (QB45, Visual Basic 1, etc). 😃

In short, that 286 was pretty much on 486 level, except for the aging 16-Bit CPU.

At some point, I've also used it to dial into CompuServe and T-Online (aka BTX/Datex-J).
Modem was a beige Creatix model, ca. between 14400 Bit/s to 33600 Bit's.

The client software ran on Windows 3.1 in Standard Mode and used pure 16-Bit instructions, making it 286 compatible.

Edit: That being said, I don't mean to say it's wrong to build an old school 286. Hercules and EGA are cool, too.
The 286 era spawned 10 years, from 1984 to ~1994, with me considering 1992 to be its heyday, before its popularity started to quickly decline in 1993.

PS: You can install memory boards in ISA slot, too. That was the original method, before the advent of the chipset.

Look for BocaRAM cards, AST Rampage, etc. Some of those are EMS boards than also can be used for Extended Memory (memory above 1MB) or XMS (has himem.sys compatible driver).

ISA XMS/EMS Memory Extension / Expansion cards: Now Running without Driver / Documentation :-)

Bocaram AT XMS/EMS memory card replica?

https://www.minuszerodegrees.net/5170/cards/5170_cards.htm

ISA or AT-Bus used to be based on the processor bus of the 80286 CPU. It's the 286's front side bus, so to say.

80286 PCs can directly, natively drive the ISA bus. They're both directly coupled, so to say. Maybe with some buffer stages I between, too. Unless a chipset decouples them both.

Depending on waitstates, clock speed, duty cycles/recovery times etc. ISA can be quite quick.
In early designs, memory was attached via ISA bus. Same goes for IBM PC/XTs and PC/XT bus.

Edit: My bad, I just realized that I was too chatty again. 😅 Sorry about that, hope you don't mind. 😔

One strange thing I noticed. Although the components on the motherboard indicate it was built towards the end of 1988, the graphics card seems to be from early 1991. So either Acer was still selling these in 1991, or somebody just upgraded the VGA...but it has an Acer VGA display. If upgrading from EGA to VGA, most people would have bought a 3rd party monitor...though I guess it's not impossible the owner just liked Acer.

Anonymous Coward wrote on 2023-04-05, 08:47:

One strange thing I noticed. Although the components on the motherboard indicate it was built towards the end of 1988, the graphics card seems to be from early 1991. So either Acer was still selling these in 1991, or somebody just upgraded the VGA...but it has an Acer VGA display. If upgrading from EGA to VGA, most people would have bought a 3rd party monitor...though I guess it's not impossible the owner just liked Acer.

Hm. Good point. My guess is that a PVGA1A was originally installed (has date code from '88 AFAIK) and that the WD90C00 was a later model meant as drop-in replacement.

To my understanding, it's possible that WD90C00 and PVGA1A (maybe also PVGA1B/PVGA1C are quite similar in design.
It's just an assumption, of course, speaking under correction.

Paradise used to be a company/trademark of Western Digital, years before the WD90C00 was released.

The only notable visual difference is that the PVGA1A was housed in a huge SMD IC,
while the newer WD90C00 is roughly in the size of a 386SX chip.
So maybe it was being made using more advanced lithography. 🤷‍♂️

Edit: The chassis has a '89 date code on its back..
My guessis that the manufacturer had obtained a license/certificate for this PC model.
If so, the manufacturer was required to stick to the same specifications all the time, if it wanted the license/certificate to stay valid.

I'm speaking under correction, but in some countries, like Germany, this was a serious matter.

For example, the German postal office only allowed the use of computer/telecommunications devices with a valid ZZF/BZT number.
This even included acoustic couplers.
Without such numbers at hand, it wasn't possible to subscribe to the BTX online service.

The forms asked for the numbers and were checked by staff.
In worst case, a specialized postal worker was visiting you at home, inspecting your PC and equipment.. Yeah, weird times.

Another reason was RFI/TVI.. PCs needed a certificate, to attest that they wouldn't cause radio interference.
Appliances, too.

DIY and homebrew wasn't forbidden, of course. But commercial products required sich certificates.

Here's anothet one: In theory, it wasn't 100% legal to do morse telegraphy with a flash light, even.
All the kids playing James Bond were essentially doing stuff in the legal gray zone.
Because, the visible light is part of the radio spectrum. And making "transmissions" without a license was illegal.
This was the logic of the German postal office back in the 20th century. Very bureaucratic.

Jo22 wrote on 2023-04-05, 08:18:

No no, I don't blame you. It wasn't meant as a complaint at all. 😅 I know those big old motherboards with their DIP/DIL RAM chip […]
Show full quote

Robx66 wrote on 2023-04-05, 06:42:

Jo22 wrote on 2023-04-05, 05:41:

The main memory is more in need, maybe. If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Exte […]
Show full quote

The main memory is more in need, maybe.
If the 286 mainboard uses Shadow memory, a humble Megabyte won't be sufficient for Extended Memory anymore.
It's then either Shadow Memory or Extended Memory.

That's one of the reasons why I have an aversion against 1 MB setups.
That being said, it's your PC, of course. You have the last say how to configure it, and that's fine. Each to his own. 🙂👍

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

No no, I don't blame you. It wasn't meant as a complaint at all. 😅
I know those big old motherboards with their DIP/DIL RAM chips.. They have a nice "chipset" and an elegant layout, but no SIMM/SIPP sockets yet.

I just said that because I sometimes end up in an argument about period-correct RAM configurations.

PS: You can install memory boards in ISA slot, too. That was the original method, before the advent of the chipset.

Look for BocaRAM cards, AST Rampage, etc. Some of those are EMS boards than also can be used for Extended Memory (memory above 1MB) or XMS (has himem.sys compatible driver).

ISA XMS/EMS Memory Extension / Expansion cards: Now Running without Driver / Documentation :-)

Bocaram AT XMS/EMS memory card replica?

https://www.minuszerodegrees.net/5170/cards/5170_cards.htm

Edit: My bad, I just realized that I was too chatty again. 😅 Sorry about that, hope you don't mind. 😔

Thats ok 😀 no problem.
I might look for those ram cards....
Probably expensive as hell !

Anonymous Coward wrote on 2023-04-05, 08:47:

One strange thing I noticed. Although the components on the motherboard indicate it was built towards the end of 1988, the graphics card seems to be from early 1991. So either Acer was still selling these in 1991, or somebody just upgraded the VGA...but it has an Acer VGA display. If upgrading from EGA to VGA, most people would have bought a 3rd party monitor...though I guess it's not impossible the owner just liked Acer.

You might be right but also I know this model was in different hardware variations made by acer. I have dig out original Acer brochure with prices and pc configurations and they were a bit different to the one I've got. Not sure if can find it again. I have some original manuals for this pc including graphics card. The graphics card is called Sigma VGA.....

I am pretty sure the Sigma VGA is not what is installed presently. Maybe the manual mentions what kind of chip it uses. It's probably C&T or Tseng based.
The replacement WDC that's in there is a good match for this computer, so I'd probably just leave it alone. Either the original had some kind of incompatibility issue or it failed.

I second this.

The Sigma card could be a Sigma VGA/H, based on a Tseng ET-3000AX.

That's at least what I think, because the picture on the manual has similarity with this card:
https://www.worthpoint.com/worthopedia/sigma- … -card-242317561

Both cards (chips) are from 1988/1989 and support same software, mainly AutoCAD, Windows 2.x, GEM, Lotus 1-2-3 etc.

What's notable, though, the ET-3000AX had a hardware-based windowing feature for text, if memory serves.
Some sort of picture-in-picture, but for text boxes. But it was rarely used by software, if at all.

Anyway, the WDC/Paradise is fine. It's a classic card and not the slowest.
DOSBox emulates it too, along with ET-4000 and S3 Trio32/64.

Robx66 wrote on 2023-04-05, 06:42:

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

If you want to increase the system's memory can't you maybe look at installing an ISA memory expansion card like the one I have in my 286: (I still need to take a look at this system of mine, I'll probably need to reprogram the keyboard EPROM though, as the sticker covering its window had been eaten away by fish moths 🙁 )

Irinikus wrote on 2023-04-15, 17:03:

If you want to increase the system's memory can't you maybe look at installing an ISA memory expansion card like the one I have […]
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Robx66 wrote on 2023-04-05, 06:42:

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

If you want to increase the system's memory can't you maybe look at installing an ISA memory expansion card like the one I have in my 286: (I still need to take a look at this system of mine, I'll probably need to reprogram the keyboard EPROM though, as the sticker covering its window had been eaten away by fish moths 🙁 )

I was thinking about it but these cards are horribly expensive 🙁

Robx66 wrote on 2023-05-11, 19:23:

Irinikus wrote on 2023-04-15, 17:03:

If you want to increase the system's memory can't you maybe look at installing an ISA memory expansion card like the one I have […]
Show full quote

Robx66 wrote on 2023-04-05, 06:42:

I wish I could add more RAM but that's maximum this motherboard can take without desoldering dram and sockets and then solder new sockets for 511000 dram unfortunately.

If you want to increase the system's memory can't you maybe look at installing an ISA memory expansion card like the one I have in my 286: (I still need to take a look at this system of mine, I'll probably need to reprogram the keyboard EPROM though, as the sticker covering its window had been eaten away by fish moths 🙁 )

I was thinking about it but these cards are horribly expensive 🙁

I know what you mean. But they're worth their money. In theory, I mean.
Even back in the day they weren't cheap.

That's because most third-party ISA memory boards supported EMS.
And EMS requires an intelligent electronics, which can swap memory in and out.
It's like an external memory controller, so to say.

By contrast, UMB cards and Extended Memory boards are just memory modules with a bit of ISA bus logic.

Anyway, if you're shorz on memory, I recommend getting some of those Lotech cards.
The 1MB RAM card and the 2MB EMS card.

The 1MB RAM card can be used to create RAM memory in the 640-1MB range for UMBs.
So you can upload drivers into that area, dreeing DOS memory.

Alternatively, you can use it for a "trick".:
You can tell some motherboards to either divide those 1MB of on-board memory into 640KB+384KB or 512KB+512KB.
If you choose the latter, you can use the 1MB RAM card to increase 512KB to 640KB and thus have 1MB RAM + 512KB Extended Memory.

Of course, this will cost a bit of performance, due to the 8-Bit bus.
But it will only matter if your programs/games use more than 512 KB of DOS memory.
The DOS drivers in the UMA are very small and I assume that the 8-Bit bus won't hurt that much in practice.

In the end, you must decide: Slow memory or not enough memory.

Alternatively, the 2MB EMS card can help you.
It will provide EMS memory to games supporting it, like Commander Keen, some Sierra game compilations (Space Quest collection) or Wing Commander 1 (for music/SFX).

EMS is also useful to Windows 3.0 in Real-Mode or PC GEOS (GeoWorks Ensemble).

But please keep in mind that the 2MB EMS card is 8-Bit, too and not fully LIM4 compatible.
The hardware is LIM 3.2 compatible (uses classic 64KB page frame), while the driver supports the usual LIM4 features.

That being said, quite a few real old EMS boards were limited to 8-Bit I/O, despite their 16-Bit ISA connector, so it's not that bad in practice.

Anyway, these are just ideas. These Lo-tech boards are being manufactured by various companies by now.
Texelec is an official partner of Lo-tech, I vaguely remember. So maybe you can get your hand on an affordable memory card at some point.

Good luck! 🙂🤞

Edit: Here are some pictures of official ISA memory boards for the IBM PC/AT.
Maybe this page helps you to find some boards on eBay.
https://www.minuszerodegrees.net/5170/cards/5170_cards.htm