Hi guys,

You may know me as Fred from ANG or now from Rewindgames. Maybe you have seen that I sold some 1050 drives at the JHV and in my webshop (at a low price, I am not making a lot of money with this hobby). One of my customers has a problem and I will send him another 1050 to keep a happy customer. But maybe one of you knows what is wrong here.

He wrote:

It will boot and load a retail game disk perfecty; as I mentioned 'Operation Blood' loads up and I can play it. However, if I attempt to format a disk then I run in to severe problems.

From inside SpartaDOS, if I try the 'Format' command the drive goes through the normal 'chugs', but when it gets to the end SDX reports 'Error formatting disk'. No variation of tracks,density or any of the other settings makes any difference.

The other scenario I have tested is to set the 1050 up as 'D2:' and then connect an SIO2PC and then set 'Aspeqt' to emulate 'D1:'. This is the setup I was advised to use to copy *.ATR images on to physical floppies. Anyway, if I use this configuration and boot in to "DOS2.5", the 1050 is properly recognized but when I attempt to format a disk I again encounter problems. It can fail in one of two ways. The drive will either 'chug' through five\six tracks after which I immediately get a handshaking buzz and then DOS reports 'Error 138'. Alternately it will chug through the full 40 tracks, but at the end of this instead of writing a new directory record it gives a solitary 'beep' and then the read/write head grinds back to track 0 and starts to 'chug' through them all again. This behaviour will continue indefinitely until I press 'break' to stop it at which point the same 'Error 138' is reported.

Can someone help? Any help is appreciated. I will make sure that the person who helped will get an Atari present from me at the next JHV Replies in German are okay, I can read German, but (sorry) I can't write in German.

Best regards,
Fred Meijer

Hi Fred,

Fred_M hat geschrieben:It will boot and load a retail game disk perfecty; as I mentioned 'Operation Blood' loads up and I can play it. However, if I attempt to format a disk then I run in to severe problems.

First, try some simple things to decrease the amount of possible issues.

- Very first test: Try some other disks. This behavior also occurs when the disk is bad, mostly all disks for use in a 1050 are over 20 years old, the have some problems sometimes. Best is to test with a disk which is working in another 1050 perfectly. Also "new" disks ("NOS") may have this problem!
- Change the mechanics. Uncommon, but maybe the head or its cable is bad.
- When the issue is located on the electronics (PCB), then try first changing the FDC (2793/2797). If this doesn´t help, replace the original one again. These FDC have a lot of analogue circuits and should be aligned. So for a quick test it´s no problem to exchange one FDC with another, but for final use it should be justified.

The following tests require some tools like a multimeter or a scope. Best is to download the 1050 Field Service Manual, where you can find some important scope pictures for test and alignment.

Sometimes some people try to "repair" a 1050 by changing every potentiometer or variable capacitor. This has mostly an effect of two things:

- Motor rotation speed
- Precompensation for FDC´s write data circuit

When somebody did such a silly thing, then reading data maybe possible, but writing and specially formatting a disk results in an error. So one of the first, whatever happens, is to check the alignments.


- Remove mechanics, PCB unpowered at this point
- Set a jumper over the both pins at TP7 & TP8 (beside pin 21 of FDC)
- Power on the PCB (without mechanics)
- Use 10K pot to set impulse width at pin 31 (FDC) to 230 nS (nano seconds)
- Use 50K pot to set impulse width at pin 29 (FDC) to 1 uS (one micro second)
- Use the variable capacitor to set period at pin 16 (FDC) to 8 uS (eight micro seconds) or use a frequency counter at set it to 125 kHz
- That´s all. Deplug power and detach the jumper at TP7 & TP8
- Reassemble drive

When this all is done and doesn´t work, use the 1050 Field Service Manual or Sam´s Computerfacts and examine all parts in the write data circuits of the PCB.

Good luck!

Regards, Juergen

I had a similar problem; disks load, but when I tried to format a disk I had trouble: when the head runs from outside to inside the sound of the steppermotor was "normal" (a smooth tak-tak-tak...), but the way back the gaps betwen the "tak-tak" were longer and irregular.

The reason was a pollution on the steppermotor´s wheel; it looks like some belt-abrasion. After cleaning the wheel the floppy works fine again.

Sleepy

Sleepy hat geschrieben:The reason was a pollution on the steppermotor´s wheel; it looks like some belt-abrasion. After cleaning the wheel the floppy works fine again.

Hehe, it sounds as if that was my old drive, which I sold to Sascha. Nice to hear that it works well again

Hi All!

Thank you for all your tips! The problem is that I don't have the disk-drive here. It was sent to someone in the UK. Postage from The Netherlands to the UK is quite cheap, but sending it back to The Netherlands is very expensive....

I will send him two tested disks. One to format and one with Dos 2.5, at this moment he has only a Spartados X cartridge and SIO2PC. The customer does not have much equipment (this is his first drive) so we do not have the option to test a lot.

But I will ask him to try to clean the steppermotor.

I hope we will find a solution. Thanks again!

Kind regards,
Fred

kfischer hat geschrieben:Hehe, it sounds as if that was my old drive, which I sold to Sascha. Nice to hear that it works well again

Yes, that´s right!

Sleeπ