Differences between 1050 versions?

[macsonny]

Hi All,

 

I have a few 1050 drives I'm fixing up. Seems I have the two variations of the drives. I have mangled to get one going after replacing felt pressure pad, re-greasing, etc. but I think the belt is slipping. I've got a replacement one arriving this week.

 

A few questions:

 

1. Are the drive belts the same between the two variants of the drives?  If not, does someone know the exact requirements for both variants with respect to length, diameter, width, etc?

 

2. I noticed that one of my drives runs great at around 344 RPM (208 mps) and the other drive runs at 288 RPM. Should there be a difference in speeds between the two variations of drives?

 

Thanks for your help.

 

Sonny

[Rybags]

Fairly sure speed should be the same - 288 RPM.

 

I've got trouble with mine (got both variants also) and devised 2 extra methods to guage RPM.  First, a strobe app for the phone.  Put a mark on the disk mech hub that contrasts against the white.  Set strobe to 4.8 Hz and run - there should be minimal movement of the mark you made.  Though that method can have accuracy problems.

Second is if you have a high speed camera - mine can do 240 FPS - count the number of frames it takes to do 1 revolution then calculate RPM from that.

[TGB1718]

2 hours ago, macsonny said:

2. I noticed that one of my drives runs great at around 344 RPM (208 mps) and the other drive runs at 288 RPM.

Are they both "standard" drives, if you have a US Doubler Mod, only visible difference is usually a piggy backed

RAM chip on the 6810 chip, if so then I believe the RPM test will fail and you need to do something like @Rybags suggests

[Zarxx]

Software wise I use this. Drive needs to be standard speed, un-happy mode, etc.

 

BASIC required - let the drive run for 10 mins or so as the speed will differ slightly when warm.

Speed Disk - Page6_24.atr

Edited February 26, 2022 by Zarxx

[macsonny]

19 hours ago, TGB1718 said:

Are they both "standard" drives, if you have a US Doubler Mod, only visible difference is usually a piggy backed

RAM chip on the 6810 chip, if so then I believe the RPM test will fail and you need to do something like @Rybags suggests

So here are my findings:

 

1. The Tandon drive likes to run at 344 RPM and works great at that speed. I did change the felt pressure pad and that made a huge difference. Drive reads, writes and formats without skipping a beat. I looked at the main board and can't see any mods.

 

2. The World drive likes to run at 288 RPM and works great at that speed. I also changed the felt pad on this unit and that also made a huge difference. Drive reads, write and formats fine. 

 

3. I have a 3rd drive. It's a World drive. It has a faulty track zero sensor I've replaced and trying to work out a mod to keep it in place. The drive has a very "tight" spinner (not the motor but the bit that clamps the floppy) and will hardly move even when I try to manually spin it. The belt is kaput and waiting on a replacement. I have replaced the felt pad on this unit too. If I lift the pad off the disk the disk still will not spin so I think it's the spindle/clamp that's tight. 

 

I can't draw any conclusions just yet but I have 2/3 working drives and hope to get the 3rd going once I work out how to unstick the main clamp.

 

Any ideas on how to loosen thing up there?

 

Thanks

 

Sonny

[TGB1718]

Have a look at this link for Track 0 sensor I did some time ago, needs no mods other than If I remember the connections to the sensor

are different, but that's just soldering

 

 

[xrbrevin]

are the bearings ok in the big drive-pulley? i had to lube them once due to a dry binding issue, but this was on a Tandon mech

if you have a decent drive belt and motor, it should overcome any mild resistance and get things moving again

[+bf2k+]

If you format and write a disk on the tandon, can you read it on the World?

 

They should both run at 288.

[Jason Young]

On 2/26/2022 at 3:14 AM, macsonny said:

Hi All,

 

I have a few 1050 drives I'm fixing up. Seems I have the two variations of the drives. I have mangled to get one going after replacing felt pressure pad, re-greasing, etc. but I think the belt is slipping. I've got a replacement one arriving this week.

 

A few questions:

 

1. Are the drive belts the same between the two variants of the drives?  If not, does someone know the exact requirements for both variants with respect to length, diameter, width, etc?

 

2. I noticed that one of my drives runs great at around 344 RPM (208 mps) and the other drive runs at 288 RPM. Should there be a difference in speeds between the two variations of drives?

 

Thanks for your help.

 

Sonny

re: Drive Belts

 

To the best of my knowledge, there are two manufacturers that could be listed on the sticker on the bottom of the drive.  Singapore and Hong Kong.  The Singapore drives are more common and drive belts can be purchased from Console5 (link below).  These are fabric re-enforced and work beautifully.  Hong Kong drives will need a belt from Best Electronics.

Regardless, unmodified drives should all run at 288RPM.

Fabric Reinforced Belt for Atari 1050, Tandon TM100, 4P, Floppy Drive (console5.com)

 

[_The Doctor__]

344 will make real copy protected disks fail.... please consider following the standards.. 288 for both, a multitude of reasons laid out as to this in threads of old and today...

[+kheller2]

Does anyone have a solution for the pressure pads --- as in new or rebuilt/hack?  I had a few new pads in storage but they are completely flat now for some reason.  I would imagine cutting some pads used on cassette tapes might work but that's a bit detailed work and the thickness will be very important.

[Jason Young]

1 hour ago, kheller2 said:

Does anyone have a solution for the pressure pads --- as in new or rebuilt/hack?  I had a few new pads in storage but they are completely flat now for some reason.  I would imagine cutting some pads used on cassette tapes might work but that's a bit detailed work and the thickness will be very important.

I have used a few pressure pads brand new sourced from Best Electronics in the US.  They are made of rabbit hair or something like that; supposedly just like the original.  Easy to replace and they stick very well.  Just make sure you scrape out all of the old pressure pad and old sticky paper so that the new one can stick to the plastic well.

As for rebuilt/hack, I've seen people use various material from Amazon and cut them to size and glue them in...  but I was lazy and just wanted a guaranteed solution that was easy and just like the original pad, which is why I ordered from Best.

 

[_The Doctor__]

I thought best had originals as a parts supplier

[+kheller2]

AFAIK, brand new pads include the plastic disc and are difference between mechs (just as belts are different).

 

[macsonny]

6 hours ago, bf2k+ said:

If you format and write a disk on the tandon, can you read it on the World?

 

They should both run at 288.

Good question. I think the answer is YES, but I'll check and report back.

[macsonny]

4 hours ago, _The Doctor__ said:

344 will make real copy protected disks fail.... please consider following the standards.. 288 for both, a multitude of reasons laid out as to this in threads of old and today...

I will scale the 344 back to 288 and see how it goes. From memory I tried that already and the drive would fail to read/write but I'll try again and report back.

[macsonny]

4 hours ago, kheller2 said:

Does anyone have a solution for the pressure pads --- as in new or rebuilt/hack?  I had a few new pads in storage but they are completely flat now for some reason.  I would imagine cutting some pads used on cassette tapes might work but that's a bit detailed work and the thickness will be very important.

I made my own. I got felt from a local hobby store. I then got really good (thin) double sided tape. This was the clear double sided tape that's almost like a firm jelly texture. I cut a small square of the tape and stuck to felt. I then used a letter hole punch to make a perfect circle through the felt/tape combination. Then stuck that to the drive and it's worked perfect for 3 drives now.

[+Larry]

What disk speed program are you using, or how are you measuring it?  If it works properly at 344, then it is a modified drive, or the method of measurement is not what we are normally used to seeing.

[macsonny]

17 minutes ago, Larry said:

What disk speed program are you using, or how are you measuring it?  If it works properly at 344, then it is a modified drive, or the method of measurement is not what we are normally used to seeing.

Using Disk Wizard II and some other DOS based program (can't remember name). Both giving me the same results.

[+kheller2]

49 minutes ago, macsonny said:

Using Disk Wizard II and some other DOS based program (can't remember name). Both giving me the same results.

Is this a stock drive? Have you looked under the shield? ?

[macsonny]

8 hours ago, kheller2 said:

Is this a stock drive? Have you looked under the shield? ?

Here's a pic - see what you think?

[macsonny]

9 hours ago, macsonny said:

I will scale the 344 back to 288 and see how it goes. From memory I tried that already and the drive would fail to read/write but I'll try again and report back.

So I tested the drive running at 344 RPM and slowed it to 288 RPM. I can say the drive would not work properly. Read floppies (just) but would not format nor write to a floppy unit I moved it back to 344 RPM. Whatever the reason - this drive will only work at 344 RPM.

 

Doing some further testing and it looks like floppies written on the 344 RPM drive will not boot on the 288 RPM drive but testing to make sure.

 

Maybe there is a mod (see my previous post with pic)?

 

Edited February 28, 2022 by macsonny
Added information

[xrbrevin]

doesnt seem right, try the official Atari RPM software here:

1050 Disk Diagnostics.atr

[TGB1718]

3 hours ago, macsonny said:

Here's a pic - see what you think?

Looks pretty standard to me

[Peri Noid]

3 hours ago, macsonny said:

Here's a pic - see what you think?

The HD74LS02P chip (top left corner, right to the WS controller) - is it cracked or is it just a piece of hair or other dust on it?