Compaq DeskPro 286n

[Denniske1976]

Hi guys...

Just got a Compaq DeskPro 286n, nice machine and in good condition except for the Dallas being flat (and since it's socketed that was an easy fix, except the battery had to be rewired from underneath the drive cage).

Anyhoo, I have a few things I'd like to know so I was hoping some of you could help me out.

1: The Conner disk in it is dying I guess, it still works and all but when formatting I get it relocating some storage units (or something, can't remember the exact message but it essentially is the "trying to locate defect cluster XXX"). So far it only does that for cluster 698 and another one, so I end up with 2048 bytes unusable (CHKDSK from DOS 4.01). But I was wondering: since the drive is also very noisy (and I mean VERY noisy with a high pitch noise when spinning idle), can I use a DOM on the integrated IDE controller? Would be kinda nice to have a DOM on the flat cable acting as IDE Drive Type 2 (it's a Type 2 drive, 21MB). Or won't that work? Seems a bit useless to me to put one of those XT-IDE thingies in there for a 286 with an integrated IDE controller (mind you, my IBM PS/2 Model 30 has an XT-IDE in it and that works like a charm). Or are there any other options (of course other than putting in another IDE drive)?

2: The system came wothout a screen, but I still had a Compaq monochrome screen around (because I knew I was gonna find a matching PC for that). It's one of the screens with the same Compaq logo on it and also the big grey rocker switch. Looks like those old 14" VGA Compaq screens (that came with the SystemPro and original DeskPro etc) just it's mono. So, I thought no problem: switch 6 sets the VGA/Text output so set it for Text and that works. I get an image so that's OK. Weird thing is though: when turning on the PC or even doing CTRL+ALT+DEL, at very first I get a "1 long, 2 short beeps" (normally that indicated the graphics adapter)... but, no error on screen and a normal working screen. Any idea what this could be? I did run the Compaq Setup Disk and I don't think I was able to setup screen, just floppy A/B and HDD C/D types and date/time and if I want NumLock on from boot or not (setup detected most things automatically anyway). Haven't checked if it happens also with switch 6 set to VGA and a color screen attached. Just thought it to be odd with the screen working etc.

Thanks for helping out!

 

[Malc]

1: Maybe put the XTIDE Universal BIOS on a NIC card and use Spinning rust / DOM / SD card in adapter or CF in adapter, You would need to use the setup disk and set hard drives to None, I have no Compaq's so never tried it.

 

[maxtherabbit]

1: Maybe put the XTIDE Universal BIOS on a NIC card and use Spinning rust / DOM / SD card in adapter or CF in adapter, You would need to use the setup disk and set hard drives to None, I have no Compaq's so never tried it.

I second this. The XUB is far more useful than a physical xtide card on anything with a 16bit databus

 

[Eudimorphodon]

If you don't care about using the whole thing you can *probably* get away with throwing a random DOM, Compactflash, or SD adapter onto the IDE port and just using the setup program to choose whatever the largest predefined drive type available is.

Regarding the monitor settings, I'm confused. Is your mono monitor a *vga* mono monitor? (IE, plugs into the onboard video card)? According to this:

https://stason.org/TULARC/pc/motherboards/C/COMPAQ-COMPUTER-CORPORATION-286-DESKPRO-286N.html

There's no switch to set a "VGA mono" monitor; VGA of that era used a sense wire to determine if a color or mono monitor was attached.

 

[dieymir]

You don't need a cable for the DOM. Simply insert it in the IDE male connector and plug the molex. DOMs are Plug an Play. It's really easy. If you aren't insterested in using it's full capacity you don't need the XUB. There are 32, 64, 128, 256 MBs DOMs available and it's easy to find matching drive types for those small sizes

 

[Denniske1976]

If you don't care about using the whole thing you can *probably* get away with throwing a random DOM, Compactflash, or SD adapter onto the IDE port and just using the setup program to choose whatever the largest predefined drive type available is.

Regarding the monitor settings, I'm confused. Is your mono monitor a *vga* mono monitor? (IE, plugs into the onboard video card)? According to this:

https://stason.org/TULARC/pc/motherboards/C/COMPAQ-COMPUTER-CORPORATION-286-DESKPRO-286N.html

There's no switch to set a "VGA mono" monitor; VGA of that era used a sense wire to determine if a color or mono monitor was attached.

Yeah that's the answer I was looking for (and what dieymir said). That's what I was wondering: "can I put in one of those i.e. 32MB DOM thingies and leave it at Type 2 drive for a 20MB partition and "originality" but with less noise" would have been a better way to ask the question (sorry, English not being my first language so getting technical is sometimes a bit difficult for me). Great to know that I can, because that's what I was thinking... I've been using some DOM 512Mb en 1GB thingies in my 486 and P60/66 computers, but they just autodetect the thing no problem. But if I can just put in one of those and choose the drive type in BIOS and go ahead with DOS etc that will be just fine! Thanks so much, guys.

Regarding the screen, I think it's a mono text monitor (would have to check the product ID, but I Googled it before and there isn't a lot to find about it other than that "it exists" so to speak, and Google didn't turn up with it being a monochrome VGA screen either, you know like the IBM 8512). Also with the switch set to normal VGA I don't get a picture at all... with the switch set to Text/Mono I get screen output the normal way. BTW the monitor also has a switch up front for normal/inverted display, dunno if that says anything? Inverted is like a white background with dark lettering (so of course I have it the other way around).

Weird thing was though: although the screen (and adapter) should be text only, starting Frogger gave me a picture as well (not very clear though as it had no colors). And yes, that screen plugs onto the on-board adapter of the PC (configurable through Switch6 ON/OFF).

 

[Denniske1976]

If you don't care about using the whole thing you can *probably* get away with throwing a random DOM, Compactflash, or SD adapter onto the IDE port and just using the setup program to choose whatever the largest predefined drive type available is.

Regarding the monitor settings, I'm confused. Is your mono monitor a *vga* mono monitor? (IE, plugs into the onboard video card)? According to this:

https://stason.org/TULARC/pc/motherboards/C/COMPAQ-COMPUTER-CORPORATION-286-DESKPRO-286N.html

There's no switch to set a "VGA mono" monitor; VGA of that era used a sense wire to determine if a color or mono monitor was attached.

Yeah sorry, just checked that and that's not my motherboard... Turns out it's a 286e, not the N model (switch 1/6 set the monitor color/mono-text):

https://stason.org/TULARC/pc/motherboards/C/COMPAQ-COMPUTER-CORPORATION-286-DESKPRO-286e-Model.html

Again sorry about that :-|

 

[Eudimorphodon]

Okay, but it still applies; if you have a mono VGA monitor you should leave that switch set to color. It says it’s for “MDA”, I think the reason it’s complaining with the beep is with that switch enabled it’s trying to initialize an add-on MDA/Hercules card and not finding it. (Remember, MDA can actually coexist with VGA.)

 

[Denniske1976]

Okay, but it still applies; if you have a mono VGA monitor you should leave that switch set to color. It says it’s for “MDA”, I think the reason it’s complaining with the beep is with that switch enabled it’s trying to initialize an add-on MDA/Hercules card and not finding it. (Remember, MDA can actually coexist with VGA.)

Well, I checked last night and the monitor is a Compaq 411c monitor (part# 114438-202) and it says "Video Graphics Monochrome Monitor" on the back. So my guess was it's an MDA/Text screen, and since switch 6 OFF means "Monitor Type MDA" I was thinking that's some kind of emulation for MDA or backwards compatibility (like my HeadStart has, that one has an ATi GSSC v5 card with a switch for color CGA or monochrome MDA on the back).

So you mean that setting switch 6 to OFF actually might mean I need to install an MDA card in the system? While that would explain while it's beeping, that would not explain the screen working and no error message appearing anywhere about a missing option board or anything. I'd think setting switch 6 to OFF would then either make the VGA second adapter for an installed primary MDA adapter board, but since switch 2/8 enables/disabled the VGA connector on-board I would still think switch 6 sets MDA/Text capability (something any VGA adapter could do right, backwards compatible to EGA/CGA/MDA?).

And as I said: I get a working screen no problem... so I'd think if switch 6 expects an MDA adapter installed there would be no output to VGA or I'd still get no image from it just as with setting the switch to VGA does (because switch 6 ON doesn't give me anything on screen, but also no beeps from what I remember, so it's a bit confusing).

 

[Eudimorphodon]

Let’s simplify this: googling for that model number gives scrambled results so: does the plug for this monitor have two rows of pins with nine possible pin positions (I say possible positions because it’s normal for monitor plugs to be missing pins) and you’re plugging it into a nine pin socket, or does it have 15 pin positions and you’re plugging it into a 15 pin socket? Unless it’s the first of those two things the MDA switch should probably be disabled, which means 1/6 on. (And the vga port should be enabled, which is apparently sw2/8 off.) If that combination doesn’t work with no beeps then something is screwed up or the Compaq has a nonstandard way of interpreting switch settings. Does it work with a different vga monitor plugged in?

 

[Denniske1976]

Well, just checked all and here's the weird thing: even with Switch 1/6 in the ON position I still get image now and still get those 1 long - 2 short beeps when booting. Setting the switch to ON or OFF makes no difference at all.

So, I thought maybe I'd have to check with the SETUP.EXE and set some BIOS settings but there's nothing there and it looks like what's connected is detected properly:


Also checked the plug (as I wanted to test with a normal VGA screen, but that won't go on since it's got a pin whereas the connector has that pin blanked), and it's a 3 row plug and it goes into a 3 row port. So I guess the screen is mono VGA then (not MDA)?


Checked the settings on the sticker inside, everything is at default settings now... nothing special, just a 12MHz 286 with 12MHz C287, 1024K RAM, one 5.25" 1.2MB A: drive and a Type 2 21.4M Conner harddisk. Checked how jumpers E4 and E11 are set (not that they have anything to do with the display) and they're default as well: mouse port enabled and 12MHz CoPro (so pins 2-3 for both E4 and E11).

I did notice there's an E1 jumper somewhere in the back kinda next to the chipset but I can't find what that does. There's also some kind of "LAN Server Mode" jumper that you can switch, maybe that's what's causing the beeps? Maybe a missing LAN card (although I haven't touched that switch and there's no expansion cards installed at all, just the hardware as mentioned above). The one green LED on the motherboard is also lit.

Here's some pics from the jumper settings and the inside (and jumper E1 in the back):

 

[Eudimorphodon]

Also checked the plug (as I wanted to test with a normal VGA screen, but that won't go on since it's got a pin whereas the connector has that pin blanked), and it's a 3 row plug and it goes into a 3 row port. So I guess the screen is mono VGA then (not MDA)?
View attachment 62356

Yeah, it's mono VGA. MDA has a nine-pin connector same as CGA (not same pinout, but same connector.) That blocked pin on the VGA port was originally assigned as "Key/Absent" when VGA was created, at some point it became an optional +5v output and the pin started showing up on monitor cables. It's an annoying gotchya you sometimes run into on really old VGA cards.

(The other gotchya is the sense pin that was used to ID mono VGA was repurposed into the DDC data channel, so there's compatibility issues both with putting a mono monitor on a newer card and putting newer color monitors on old VGA ports. Fun.)

It's concerning that it's complaining with those beeps. (which if the translation I can find is right do mean "bad video card") Hopefully there isn't actually some kind of spurious problem with the built-in VGA on the machine. The switch settings chart on the computer seems to agree that the proper setting *should* be SW1-6 on, SW-2-8 OFF, if the monitor doesn't come on with that setting that's weird.

I wonder what the heck SW1-3 does? "Option ROM enable" isn't very enlightening.

Just to check: is the CMOS battery on the computer holding a charge? I wonder if it could be screwing up on power-on because the CMOS settings are getting corrupted.

 

[Denniske1976]

Yeah I didn't get that option ROM enable setting too, but maybe you need to enable that when cards are installed. I have a PDF where there's a whole bunch of card (external diskette adapter, tape adapter, memory board etc) and those also have switch settings etc.

CMOS battery is actually a new one, since I got it with a CMOS Battery Low message upon booting. I redid the DS1287 with a new battery that I checked with a multimeter.

I was just looking for some more info on the net, since that E1 jumper puzzles me... I think that might be the onboard VGA and I just stumbled upon a site that doesn't really show if that jumper does anything but the 286e motherboard on that site had some kind of memory daughterboard on it. What if E1 is to set something for VGA memory (i.e. 512K vs 1M) or something and the memory board is missing here. Wouldn't setting it to 1M with only 512K also cause this? Problem is, I can't find what E1 does so I could go ahead and just see what happens if I enable or disable it and see if there is a difference?

 

[Denniske1976]

Well, taking off that E1 jumper makes the machine do nothing anymore :-D :-D

The jumper is an ON/OFF one, so not 1-2/2-3 or something. With the jumper off, the machine turns on and that's it. No screen, no beeps, no floppy read/boot actions, no HDD read/boot action... just turns on and that's it (wonder what that is for). I'll take the drive cage off again tomorrow to see what there's underneath there, because if there is an E1 jumper and an E4 and E11 jumper, there should be some more maybe. When I put that jumper back on E1, everything is back again at 1 beep - 2 short beeps and a normal boot without errors.

Time for bed now (I'm in Holland so uhm... yeah).

Oh yeah, this was the board photo I was referring to: https://computer-retro.de/Bilder/Mainboards/Compaq_DeskPro_286e_Mainboard-AMD-CPU.jpg

This one has some kind of daughterboard in that metal cage thingie... and there's an E3 jumper as well I see, wonder what that does.