Had one of those BITD. I was able to make a cup of tea waiting for Microsoft Works
to load up. ATRAIN would run on it. Anything Windows related faghettaboutit!

Alex_03 wrote on 2024-01-11, 16:24:

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.

That is a 1.2MB FDD, make sure the bios is set as such.

appiah4 wrote on 2024-01-12, 05:39:

That is a 1.2MB FDD, make sure the bios is set as such.

It is, yes.

So I had an idea that the drive was not running at the correct speed. The wikipedia page for floppy formats says that a IBM PC/XT compatible 5.25" DS DD disk should spin at 300rpm. However, the jumper settings for IMB compatibles on this drive set the speed at a fixed 360rpm. I verified with my oscilloscope that the drive was running at 360rpm using the index pulse.

I set the jumpers as shown in the photos attached. I based these settings off of both the first and second row of the jumper settings table. With these settings the drive spindle changes speed based off of pin 2, and when attempting to read or format a disk the speed cycles between 300 and 360 about once per second before stopping at a general read failure.

I feel like this is a step in the right direction, just makes me wonder why the "PC compatible mode" is incorrect for lower density disks.

After doing some more reading, I think I was wrong about the speed thing. running 360rpm on a DD disk will not prevent it from reading, correct me if I am wrong.

I installed ImageDisk for it's test utilities, I played around in there for a while but I don't know enough about this stuff to use any of the information I got.

Small update, after getting nowhere with the FDD I put some effort into troubleshooting the ET4000 with that graphics glitch, that happened over here; https://www.eevblog.com/forum/repair/tseng-la … deo-corruption/
We really did not get anywhere, but It is safe to say that the ramdac is fine, and I think a 98% chance that the memory chips are ok. That being said if anybody here has any other ideas, I am willing to try them at this point. I would mess around with the ROMs but I have nothing to dump/program them.

I am not in a rush to get the 5.25" FDD running, since the 3.5" works fine, perhaps I will keep an eye out for an IO controller card. If you would like to recommend decent IO and VGA cards I would be curious to know your thoughts.

Alex_03 wrote on 2024-01-17, 20:38:

Small update, after getting nowhere with the FDD I put some effort into troubleshooting the ET4000 with that graphics glitch, that happened over here; https://www.eevblog.com/forum/repair/tseng-la … deo-corruption/
We really did not get anywhere, but It is safe to say that the ramdac is fine, and I think a 98% chance that the memory chips are ok. That being said if anybody here has any other ideas, I am willing to try them at this point. I would mess around with the ROMs but I have nothing to dump/program them.

I am not in a rush to get the 5.25" FDD running, since the 3.5" works fine, perhaps I will keep an eye out for an IO controller card. If you would like to recommend decent IO and VGA cards I would be curious to know your thoughts.

TM = 1 (Termination)
DS0 = 0 (Drive Select 0)
DS1 = 1 (Drive Select 1)
DS2 = 0 (Drive Select 2)
DS3 = 0 (Drive Select 3)
IU = 0 (In Use)
MS1 = 1 (Pin2 can select disk density)
D-R = 1 (Off = Disk change signal for PC/XT / ON = AT )
MS2 = 0 (off= single speed/ on= Pin2 selects Disk speed)

Use a floppycable with a twist.
Both dirves have to be DS1.
Drive A: is connected after the twist in the cable. (the twist turns a DS1 Drive into a DS0 Drive)
Drive B: is connected before the twist. (closer to the mainboard)

Be sure the cable is a proper Floppy cable and not a MFM cable.
MFM cables look the same but the twist is in another position.

A proper floppy cable has the twist on position 10-16 .

DerBaum wrote on 2024-01-17, 21:19:

Be sure the cable is a proper Floppy cable and not a MFM cable.
MFM cables look the same but the twist is in another position.

A proper floppy cable has the twist on position 10-16 .

I will play with this info later, thanks!

Also, I got the Tseng ET4000 figured out. The problem was caused by "hidden refresh" in the bios, disabling it fixed the graphics issue. I wouldn't have thought the the issues would be related to system memory but I cant argue with results.

I need a mouse for this computer, will any mouse with a 9-pin serial connector work? 2 or 3 button?

Alex_03 wrote on 2024-01-19, 00:10:

I need a mouse for this computer, will any mouse with a 9-pin serial connector work? 2 or 3 button?

That does not matter. Any serial mouse should work.

Disruptor wrote on 2024-01-19, 01:34:

Alex_03 wrote on 2024-01-19, 00:10:

I need a mouse for this computer, will any mouse with a 9-pin serial connector work? 2 or 3 button?

That does not matter. Any serial mouse should work.

Thanks.

As for the floppy drive, I ended up removing the jumper on "IU" as suggested, things seem to be working better, But it still seems weird.

At one point I was unable to format a "new" 360 disk, it would give a track 0 error, but dos would let me format them as a 1.2M disk. I then fiddled around in IMD with the format/erase tools, and I even ran a magnet over the disk at one point. After the IMD and magnet shenanigans I was then able to format the disk as a 360k in dos.

Does anybody have any explanation for behavior like this? It seems like this drive is working, but not playing very nice with 360k disks?

Basically you should not write to or format 360 K discs in a 1.2 M drive.
Just read them.

It is because the read/write head in 360 K drives use 40 tracks per disc and may have problems reading the smaller tracks from a head for 80 tracks.

Disruptor wrote on 2024-01-19, 02:11:

Basically you should not write to or format 360 K discs in a 1.2 M drive.
Just read them.

It is because the read/write head in 360 K drives use 40 tracks per disc and may have problems reading the smaller tracks from a head for 80 tracks.

Ok, I had read that you will run into problems doing that but I wasn't sure. I just need to keep an eye out for another 360k drive or another 1.2M drive and some disks.

As a proof of concept I will attempt to get one of the 360k drives from my brother's XT working on this machine when I get a chance.

I finally have a serial mouse, it's not the greatest but I hope it will work.

Does anybody know where to fond a driver? Are the drivers universal or specific to each mouse.

Basically serial mouse drivers are universal.
There may be a difference between 2- and 3-button mice.

I am having some issues getting drivers running. I downloaded and imaged a microsoft mouse 9.01 disk but ran into trouble. Attempting to run the setup.exe from dos gives a sector not found error, and trying to run the exe from windows 3.1 fails, saying that there is not enough memory(which I can believe).

Is there a way to do this without the setup program? or should I try a something different?

There should be a LMOUSE.COM on your Windows disks. If it is compressed, look for LMOUSE.CO_
You can use this driver.

You can also use Cutemouse which does not require an installer and has a very small memory footprint, it should be available to download on Phil's Computer Lab's resources/downloads page. Alternatively just google it, and download versions 1.9 and the 2.x betas. Try them all, some work better than others on specific configurations.

appiah4 wrote on 2024-02-01, 08:42:

You can also use Cutemouse which does not require an installer and has a very small memory footprint, it should be available to download on Phil's Computer Lab's resources/downloads page. Alternatively just google it, and download versions 1.9 and the 2.x betas. Try them all, some work better than others on specific configurations.

I saw cutemouse in my searches, but the description made it sound like it was only for DOS, I will look at it again though.

So you need a driver for a serial mouse in Windows?
What happens when you pick a generic driver in Windows setup.exe ? (Setup can be either run from DOS or Windows)