DOS Games Discussion

[fabiobol]

Hi, there is a problem on my Compaq ProLinea 3/25zs, with a i386SX-25 MHz CPU, 4 MB RAM and HD Quantum 540 MB. When turning on the system, the monitor views the video BIOS and system BIOS information, and then shows "601-Diskette controller error". I tried everything, from changing the FDD to changing the cables, but nothing. The system doesn't go on and remains there. What can I do?

[Wally]

Your motherboards stuffed..

WTF would you use a 386 for anyway..


The only solution would be turning the FDD drive off

[fabiobol]

So, in your opinion, the motherboard is broken, in some ways... well, I will throw it away! Turning off the fdd is impossible, because the System BIOS in the Prolinea models is installed on the HDD!!!

[johpower]

Hi Fabiobol,

Did you figure it out or just set the PC aside?

Before we start, remember to unplug and ground yourself to the PC case when handling internal parts. That HDD controler notice should be checked. Controllers do die and the older PC's usually did NOT have onboard IDE connector. If not, a card in an ISA slot must be checked. It will have the data cable from the drive attached. Some will have the floppy data cable also attached. Pull and reseat the card, checking edge connectors for corrosion and dust (pencil erasers are good cleaners). Now pull and seat all IDE data cables and try a boot. Enter the BIOS setup to check what comes up.

I've had many 286-486 problems over the years. Compaq's of this vintage can be very obtuse. Anyways, go to the BIOS setup (either F1, F2, F10, esc, del or ctrl-alt-esc likely) and see if the hard drive is still detectable (hope you have the IDE detect feature). If so but it dissappears after a boot or after sitting for a bit, the battery is suspect (....system time resetting? BIG HINT). With the PC off, find and volt check the battery. You'll be real lucky if it has an easily replacable coin bat. It should have at least 3 volts (or 2.5 volts to work at all), replace if not. Is it even partly showing a white "fuzz" of leakage? Remove and discard. Near by the old battery, look for 4 small "jumper" pins in a line, hopefully marked "bat" or "ext bat". Some will have 3 pins in a line with a 4th pin obviously missing. An "external" battery can be added if there is either of these. Sometimes an external battery jumper must be thrown to enable it. NOTE: POLARITY IS IMPORTATANT!!! (don't you just love old momboards, hmmmm?)

Before you get too far into this, some momboard makers still have these beasts on their websites. All the old jumpers and even a manual or layout diagram can be d/l'd. You Compaq should be better than most here, IF the HP merger brought the old mobo files along.

For those not so lucky, the manufacturer, board ID and version will hopefully be printed on the board or a sticker. It's also very common to find a small sticker on the side of the last ISA slot. The case bottom/side often blocks it and you'll have to get a mirror or even pull the board to read it. It may say simply "386-bc4" or "mb76g" or something as helpful. The BIOS chip may have a sticker. The case itself is often no help at all, thou your Prolinea isn't in that class.

Hope that helps some. If you want to stay with pre-Pentium hardware for some compatability reason, the high end 486DX's will be your best bet. I was very happy with my Cyrix 486DX-80, 8MB, VL bus PC for some time. It didn't run Windows ever. I used DOS 6.22 and GEOWORKS till 1998.

[fabiobol]

Thanks, i used an ISA controller, but now the BIOS doesn't keep the informations. I must use an external battery. I will connect 2x 1.5 Volts - 2350 Ah batteries. I will see if it works.

[johpower]

1) Since these sound like AA's or AAA's, a battery holder w/velcro does a great job. You'll likely have to soldier the correct connector on the leads. Old PC case speakers usually have the right connector to scavange.

2) Often you'll find a pinhole on the connector blocked/plugged or non-existant for one of the pins your Momboard DOES have. This "keyed" the cable so as to put it on only one way. Once again CONTINUITY is essencial and doubly so if you're assembling the cable. A block or plug can usually be worked out with a straight pin and/or sharp tweezers. An X-acto knife with a long sharp tip to drill through the plug is your alternative if this doesn't work. It's the only option if the hole doesn't exist at all. Use a light, deliberate touch as you twirle the handle between your fingers. I prefer this over a dremel drill. You just don't need that much force.

3) Forgot to mention there are a few 2-pin bat pin sets. Rare but true.

4) No way to determine the possitive pin on the 4-pin connector? No Number 1, no +, no corner mark? Short of tracing the board traces by magnifier (still a good idea) on both sides, you can detach all the drives and cards but leave the PS attached. Set your volt meter to any scale above 5 volts DC. 1st see if you get anything off the old battery. DO NOT trust the result if the voltage is below 1/2 a volt. It is possible it has reversed (yes, it happens!). To determine +, use the leads of the 4-pin connector you've got. 2nd option, a pair of clip-ended test leads. Clip your volt meter to the leads/clips and BE SURE THAT THERE IS NO POSSIBILITY THEY WILL SHORT ANYWHERE TO ANYTHING without considerable provocation. The battery voltage should show at the ext bat pins. If no response, check if there's an "external battery enable" switch/jumper and try again. If no battery or no voltage results, turn on the power. Leave the power on only the few seconds needed and switch off. The amperage is fairly low in this circuit so any typical meter that handles >5 amps will be safe. The voltage reading isn't all that important (though it proves that the pins are live and not shorted). The polarity displayed is. Mark the board with a RED/ORANGE sharpe and get on with it.

5) If you use rechargable batteries, beware that some only average 1.2 volts (see sales card that came with the type or the lettering on the case). You'll need 3 instead of 2.

[fabiobol]

Thanks a lot. I have replaced the integrated battery with another, similar to the batteries that you can find in watches, and now the bios is still keeping the information.