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A beginner with a 386SX

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Reply 20 of 64, by Alex_03

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Something in my setup is not very happy, the 5.25" floppy drive seems to work very intermittently.
With a disk that I know works, I can read it just fine, take it out, and then it will refuse to read again, throwing either a general read failure or a sector not found failure.
I don't think there is a floppy controller issue because the 1.44M 3.5" fdd on the same cable has no issues.

I cleaned the heads with a folded scientific wipe and some pure isopropyl alcohol, they look very clean but who knows at this point.

Reply 21 of 64, by Jo22

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Hi, if it's a software issue, you can try 2M-XBIOS.
It's a floppy BIOS for XTs and ATs that can be loaded on DOS.

https://minuszerodegrees.net/2M-XBIOS/2M-XBIO … 4M%20as%20B.htm

It could a hardware-related issue, also.
There's often a conflict between floppy controller and an IDE card.
It's related to the ready line (RDY). Some multi i/o cards had a jumper for that signal.

Another issue could be a memory manager.
Because, floppy access uses DMA controller.

It's hard to do a diagnose from the far, so I can only wildguess.

Anyway, I would try to troubleshoot things with a clean boot (no EMM386).

PS: If you're using a CF adapter, please make sure it doesn't do weird things. I vaguely remember there's one pin that causes all kinds of weird stuff.

Re: 386sx motherboard does not like compact flash adapter / DIP switch question

Edit: It's just guessing here of mine. The issue could also be related to how the jumpers are set on the other 5,25" drive.
The IBM PC platform doesn't follow the Shugart standard. Things like motor signal etc are handled differently.
So please check jumpers, if possible. It's good to check the drive first before taking the PC apart. 😉

Edit: There's also a disk change signal, I believe. So DOS knows the floppy had been replaced. Maybe it's related to this, not sure.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 22 of 64, by Alex_03

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I tested several things this morning.

The 2m-xbios is XT only, not sure where to get an AT one, if it would even do me any good. I am pretty sure the FDD controller is one of the "Chips" chips on the board.

I tested the floppy drive using a dos 6 setup disk with the IDE CF card disconnected, as well as hitting f5 with the CF card to disable things, still did not work.
I did check pin 28 on the CF adapter and it is not grounded at least.

my motherboard has a scattering of jumpers on it, some of which are labeled. There is one jumper called "DRV type", which sets "S.S" and "D.S", and it is currently set to D.S. This seems like it is referring to floppy disks or drives, but I don't know why there would be a jumper for this. There is also another jumper called "Flop PC", and you can select "norm" or "alt", currently it is in norm.

I only have one 5.25 drive connected, the other is a 3.5.
Also, I should have looked at the spec sheet for my drive earlier, it had lots of good info, go figure. I have attached two pieces of the spec sheet below. I need to get my hands on some of those mini jumpers, because currently the ones on the drive are all over the place.

Reply 23 of 64, by Alex_03

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If I am not getting anywhere with the 5.25" floppy, I can mess with it another time. I did check some signals on the floppy cable, they looked fine.

The next thing that I want to try and do is get a sound card working. I have a soundblaster AWE64 (CT4520), I don't know where it came from, but it is in my hands and I think it works. I read that an awe64 is not the best for a 386/DOS, but I still want to try and see if it will work.

I am also open to buying something cheap, my standards are not very high if any body would like to recommend a sound card.

Reply 24 of 64, by DerBaum

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Alex_03 wrote on 2024-01-08, 22:07:

..something cheap, my standards are not very high...

Then everything with a original OPL chip (or a relabeled one) should be fine. or at least a proper implementation of it.
The AWE card can use its integrated wavetable to make "nicer" sounds. If you want a soundcard with integrated wavetable your choices shrink down quite a lot, and the prices get higher...
A lot of cards with proper OPL implementation also have a wavetable header to fit your own wavetable if you like.
That are some things to consider...

FCKGW-RHQQ2

Reply 25 of 64, by Jo22

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Alex_03 wrote on 2024-01-08, 22:07:

If I am not getting anywhere with the 5.25" floppy, I can mess with it another time. I did check some signals on the floppy cable, they looked fine.

Sorry to hear, I wished I was more helpful here
It's just so difficult from the distance. 🙁

Anyway, I'll see if I can find the AT version for you. Must be here somewhere..

Alex_03 wrote on 2024-01-08, 22:07:

The next thing that I want to try and do is get a sound card working. I have a soundblaster AWE64 (CT4520), I don't know where it came from, but it is in my hands and I think it works. I read that an awe64 is not the best for a 386/DOS, but I still want to try and see if it will work.

I am also open to buying something cheap, my standards are not very high if any body would like to recommend a sound card.

Well, the AWE isn't bad per se. The DAC and the Emu8000 are fine. It's just the OPL3 replacement that isn't exactly sounding like a real OPL3.

In fact, the Emu 8000 is being supported by quite a few games.
And it can be used to play back MOD files (Impulse Tracker, Amp for Windows etc).

It also can be used to simulate an MT-32 with default instruments.
All games that don't upload samples should sound similar to an actual MT-32.

So it's not a bad card for classic titles.

It's just FM (OPL3) that's not so great.
But maybe you can live with that limitation.

Again, games supporting the Emu 8000 should be fine.

Another problem might be the use of Plug&Pray and the need for CTCU/CTCM.
But Unisound might be an alternative here.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 26 of 64, by Alex_03

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Small update, I tried a random dos game that I had (I have a bunch of old floppies from somebody), and some sound actually worked but it sounded horrible, not that I know exactly what it should sound like though.

Jo22 wrote on 2024-01-08, 23:05:

Another problem might be the use of Plug&Pray and the need for CTCU/CTCM.
But Unisound might be an alternative here.

I did install CTCU and CTCM directly from creative's website, it actually went well and the configuration utility is nice to use. What is a little off-putting is the fact that the audio device test from CTCU results in a "run-time error R6810" while testing the interrupt, which is IRQ 5 apparently.

on a different note, said dos game looked like the attached file, all kinds of flickering corrupted spots. (this is not going well 😜).

Reply 27 of 64, by Alex_03

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Edit: that corruption free area where the character is was where the character was moved back and forth, so the character sprite is not corrupted and cleans the area it passes over? not sure if that hints at corrupted textures or bad Vram. My graphics card is a 1MB ET4000AX that I recently got for relatively cheap, perhaps we know why. Also it is worth mentioning that there are no issues inside basic text prompts, even with color on the screen.

Reply 28 of 64, by appiah4

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Alex_03 wrote on 2024-01-08, 22:07:

If I am not getting anywhere with the 5.25" floppy, I can mess with it another time. I did check some signals on the floppy cable, they looked fine.

My experience is that these troubles are usually misconfigured jumpers, particularly wrt DS select and Terminate jumpers..

Reply 29 of 64, by Alex_03

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appiah4 wrote on 2024-01-09, 08:01:

My experience is that these troubles are usually misconfigured jumpers, particularly wrt DS select and Terminate jumpers..

I am missing a jumper on the drive, some more are on the way. I used the jumpers that I had to set term on and DS = 1, following the jumper settings recommended for PC/AT compatibles in the spec sheet. Thinking of termination, should I try turning termination OFF since this is drive B? i.e not at the end of the cable?

Reply 30 of 64, by appiah4

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Alex_03 wrote on 2024-01-09, 14:01:
appiah4 wrote on 2024-01-09, 08:01:

My experience is that these troubles are usually misconfigured jumpers, particularly wrt DS select and Terminate jumpers..

I am missing a jumper on the drive, some more are on the way. I used the jumpers that I had to set term on and DS = 1, following the jumper settings recommended for PC/AT compatibles in the spec sheet. Thinking of termination, should I try turning termination OFF since this is drive B? i.e not at the end of the cable?

Yes, no termination and DS1.

Reply 31 of 64, by Jo22

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About the graphics glitch.. Please try to check the VGA card for an IRQ2 jumper and disable it.
IRQ2 was a vertical retrace interrupt used by EGA.
Some VGA cards still have it enabled.

That could cause a conflict with IRQ2/9 of a Sound Blaster's MPU-401. It often uses IRQ2/9 and port 330h.

Anyway, it's just an idea. Maybe it's something else.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 32 of 64, by Alex_03

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appiah4 wrote on 2024-01-09, 18:40:

Yes, no termination and DS1.

No change unfortunately, just spits out a sector not found error.

Reply 33 of 64, by Alex_03

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Jo22 wrote on 2024-01-09, 18:48:

About the graphics glitch.. Please try to check the VGA card for an IRQ2 jumper and disable it.
IRQ2 was a vertical retrace interrupt used by EGA.
Some VGA cards still have it enabled.

This card from Compuadd only has one unlabeled jumper right next to the isa slot, moving the jumper has no effect. I removed all socketed ICs, and cleaned the sockets, no dice.

Reply 34 of 64, by Jo22

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Alex_03 wrote on 2024-01-09, 22:29:
Jo22 wrote on 2024-01-09, 18:48:

About the graphics glitch.. Please try to check the VGA card for an IRQ2 jumper and disable it.
IRQ2 was a vertical retrace interrupt used by EGA.
Some VGA cards still have it enabled.

This card from Compuadd only has one unlabeled jumper right next to the isa slot, moving the jumper has no effect. I removed all socketed ICs, and cleaned the sockets, no dice.

Ah, okay. Sorry about that. 🙁
Some models have a jumper, though.

This one here has it in the lower right corner:

https://ko.m.wikipedia.org/wiki/%ED%8C%8C%EC% … BC:ET4000AX.JPG

But there are several different models. And it's not certain that the jumper fixes the issue.
It was just an idea, rather.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 35 of 64, by Alex_03

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I should have mentioned that I also tested the game without the sound blaster installed in case of an irq issue, unfortunately it made no difference.

Edit: I traced the jumper to the IRQ2 pin on the ISA connector, so confirmed a IRQ2 jumper.

Reply 37 of 64, by Alex_03

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appiah4 wrote on 2024-01-10, 05:54:

Are you certain it is set correctly as 360K/1.2MB drive?

Could you clarify?

There are several places I could change drive settings. First I could change the setting in the BIOS, which allows you to select either 360k 5.25" or 1.2M 5.25", currently It is set for 1.2M, which worked intermittently.
There are also different jumper settings on the drive itself, At the moment it is set according to row 3 on that image I posted earlier(minus termination), changing these around did not have any noticeable effects.
Finally there are some random jumpers on the motherboard pertaining to the floppy, a picture is attached. I am not sure what most of these actually do.

Reply 38 of 64, by appiah4

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I was not actually referring to the jumpers on the drive itself, but some drives do have jumpers on them to control rotation speed which can cause problems with reading 360K disks if it is a 1.2M drive that is misconfigured.. Though I do not quite understand whether this is the case here or not. Can you let me know the full model number of your drive? I was referring to the BIOS setting being right with regards to whether its a DD or HD drive..

Reply 39 of 64, by Alex_03

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The drive is a Chinon FZ-506, I think the spec sheet is easy to find. The bios has two options for 5.25" drives, 360K and 1.2M.