Atari 260ST computer

[nlpe1goo]

Hi,
I found on my attic an Atari 260ST computer. I connected it to a monitor with scart input and powered it up. Fortunately I get a picture but the mouse can only move up and down but not from right to left and from left to right. I don't have any other documentation of this computer. Is there any service doc of this thing?
Description of the behavior of the mouse: The mousepointer start after reset in the middle of the screen but moving up and down does move the pointer as expected up and down, but moving the mouse to left or right the cursor goes to the left of the screen and stays there while moving up and down works.
Any help is appreciated.

[locknut]

Have you removed the ball and made sure both the rollers are clean and rotate freely? Next step is to make sure there's no fluff inside fouling the optical gates.

There's a teardown here, if it's the same or similar type

https://youtu.be/O2PlfpM-mH0

[paulsherwin]

Mechanical mice are notoriously unreliable. As said, you need to dismantle it and clean all the moving parts carefully and thoroughly.

[SiriusHardware]

The most common joystick / mouse related problem is ring shaped cracks in the solder joints on the 'D' sockets which the mouse / joysticks plug into. If you can't find an obvious problem with the mouse - like maybe a break in one of the wires between the mouse and the plug, that is where the problem is going to be - it's very common.

I think you can 'drive' the mouse pointer with the keyboard by holding down one of the keys, possibly ALT, while pressing one of the cursor 'arrow' keys, but obviously you really need to fix the mouse problem.

[SiriusHardware]

Incidentally the 260 ST sounds like a fairly rare thing, as the series only really took off with the introduction of the 520ST / 1040ST.

I take it this is one of the ones which has an external floppy unit, not like the later F/FM versions which had an integral floppy drive on the right hand side?

[nlpe1goo]

Originally Posted by SiriusHardware

Incidentally the 260 ST sounds like a fairly rare thing, as the series only really took off with the introduction of the 520ST / 1040ST.

I take it this is one of the ones which has an external floppy unit, not like the later F/FM versions which had an integral floppy drive on the right hand side?

You are right, this has an external floppy-drive.

[nlpe1goo]

I opened the mouse, cleaned it and checked the connection to the DB9 connector. No broken contacts found between the mouse and the connector. The behavior of the mouse keeps the same. Could it also be something on the motherboard? Could it also be a defective led/photodiode?
Thanks for the tip with the alternate key. Pressing alt and the cursor keys you can move the mousepointer Pressing alt and the insert key does the same as pressing the mouse button. I didn't connect the diskdrive to it yet, but I ave no disks which the Atari could possibly read unfortunately. How does the disk format looks like? Are there any images available anywhere?

[SiriusHardware]

If taking the 'ball' out and moving the rollers with your fingers does not make the mouse pointer move both left and right -and- you have checked all of the physical aspects of the mouse such as the cleanliness of the rollers, found no obstruction in the LED beams which shine through the spokes of the 'wheels' which are moved by the rollers, found no problem with the continuity of the cable from end to end, then the next most likely cause of this problem is cracked solder joints on the pins of the 9-way 'D' connectors which the mouse / joysticks plug into. To check this, you would need to dismantle the machine and inspect those solder joints on the 'track' side of the PCB. I can't remember, are the ports on the right hand side of the machine, or on the bottom underneath the keyboard on that version?

For disc images, probably one of the ST specific forums like Atari-Forum or AtariAge would be the best place to ask. If your machine is eventually booting to the GEM desktop (after quite some delay) it means your machine has its operating system (TOS) in ROM, which is lucky as early 260s came with TOS on disk and could not be used without it.

It sounds to me as though your machine will work OK with any valid -early- Atari ST formatted disc (game disc, utility disc, demo disc, etc) if you just insert one and reset the machine.

This machine probably has a 360K single sided disc drive (what is the model number of the external drive?) - later on, the standard was 720K double sided so be aware that many existing ST discs will be 720K and won't work in your drive.

[SiriusHardware]

Many of the Atari ST specific forums have archives of Atari ST discs in '.ST' format which is essentially an 'Image' of the disk. '.ST' images can be written back to a real disc using the linux DD command if you have a linux machine with a suitable floppy disc drive.

[nlpe1goo]

Originally Posted by SiriusHardware

It sounds to me as though your machine will work OK with any valid -early- Atari ST formatted disc (game disc, utility disc, demo disc, etc) if you just insert one and reset the machine.

This machine probably has a 360K single sided disc drive (what is the model number of the external drive?) - later on, the standard was 720K double sided so be aware that many existing ST discs will be 720K and won't work in your drive.

The Atari has a 360KB single sided disk drive. I had some DD disks available and formatting them went successful. TOS boots from ROM indeed. I'll check the DB9 connector on the motherboard later, but almost everything is working, except the mouse so as I can see so far. The next challenge is the floppy drive for the PC. I've linux running but no floppy drives. I'll buy an external usb floppy dive.

[SiriusHardware]

The original Atari ST disc format was similar to, but not the same as, the DOS format, so discs written by early version TOS can not be read from or written to by DOS and vice-versa.

From TOS 1.04 this changed, Atari STs could read from and write to DOS formatted discs (360K or 720K, according to the drive fitted in or connected to the ST) and PCs with 360K / 720K drives could read from and write to discs which had been formatted in the Atari ST. This made it much easier to exchange files between Atari STs and PCs.

Unfortunately your ST260 is likely to have TOS 1.00, which doesn't have this direct PC DOS disc compatibility.

Bear in mind that the external USB drive you buy will be designed to read / write 1.44MB floppy discs - there are stories which say that such drives don't always work well with 720K or 360K discs, but it is worth a try.

I've just thought, actually - does modern Linux still support floppy drives? My instinct says yes, but best to check before buying any hardware.

[nlpe1goo]

HD disk-drives can cause a lot of problems, indeed. My Scrumpel 68HC11 uses HD floppy drives in DD mode. Formatted with them is OK but with DD disks formatted in a DD drive can cause problems because the HD drives write on a smaller track then DD drives. (These have a more wider track.) Without a DD floppy with BASIC i.e. on it the Atari isn't very useful . And I've no DD drives anymore only HD drives with DD mode.
Checking the DB9 connector on the motherboard failed also, without using brute force I cannot disconnect the keyboard from the board. (I'm afraid to break the connector) Perhaps a nice project for next winter.... Thanks for the information anyway. Still a question? How can I see which version of TOS I have? If I click on info then it shows only running TOS with a copyright notice (1985) without version number.

[TonyDuell]

The ST mouse is, I think a quadrature-output mouse. The mouse itself is very simple, essentially just the LEDs and photodetectors. For each axis there are 2 signals back to the computer, each with its own pin on the DE9 connector. As the mouse is moved, these cycle through the states 00 01 11 10 00... or the reverse.

If one signal in the horizontal direction is not changing (either due to a broken connection or a fault in the mouse or mainboard electronics) then you might well get the effect you are seeing.

Do you have a 'scope or logic probe? If so, probe the 2 connections in the mouse (1 at a time) that carry the X-axis wires back to the DE9 connector while turning the horizontal-motion shaft/wheel. Are both changing state?

[SiriusHardware]

The original Atari ST basic (as supplied on disc with the machine) is not really very good - if you would be interested in using BASIC on the ST then I suggest you look for archived discs and documentation for 'GFA-BASIC' for the ST. That version is so much better that many demos which you might think were written in assembly language were written in GFA-BASIC.

You should be able to find a '.ST' of the ST BASIC disc somewhere online but if not let me know and I will see if I still have mine, I might be able to make an image of it and email it to you.

TOS version - good question, I think the original version TOS 1.00 does not 'announce' its version number under 'info' but later versions do and have other distinguishing features, for example TOS 1.04 is known as the 'Rainbow' TOS because it displays a rainbow coloured Atari 'Fuji' logo as well as the version number.

If your ROMs are a 6-ROM set then I think you should be able to upgrade the TOS to V1.04 by programming its code into 6 x 27256 EPROMs (I have done this on my original 520STFM, which originally had TOS 1.00). If you do this be sure to find the correct ROM images for the machine's current 'Country' so if it is a Dutch machine you may need the matching Dutch TOS, if it is a German machine you will need the German version of TOS 1.04, and so on.

You can play with / test floppy disc images much more quickly if you compile and install the PC-Linux Atari ST emulator 'Hatari' which lets you 'insert' .ST files as though they are actual loaded discs. It is very mature now and works very well.

[nlpe1goo]

Originally Posted by SiriusHardware

You can play with / test floppy disc images much more quickly if you compile and install the PC-Linux Atari ST emulator 'Hatari' which lets you 'insert' .ST files as though they are actual loaded discs. It is very mature now and works very well.

I installed hatari on my linux machine and found a gfa basic disk image. This works. I had to download the freetos image. Is it possible to program this in the eproms also and put them instead of the original one in the Atari?

[SiriusHardware]

I can't see why not, but if it was just an issue of not being able to find images of original Atari TOS ROMs... I'm fairly sure they are there to be found if you try.

Unfortunately our works IT is so locked down it blocks us from all sorts of things including anything which it thinks might be gaming related, so I can't go looking just now. In the past I have found them as both single image files (for use with emulators) and multiple image files (originally read from / for programming into EPROMs).

It would help to know which country / nationality your machine is. (I am not assuming it is a specifically Dutch machine, because I don't know where you got it from).

If the FreeTOS image is a single image file you will have to split it six ways in order to programme it into six actual chips. I don't know how compatible FreeTOS is with legacy software, I have only ever used original TOS and original TOS images in my ST / In Hatari.

[SiriusHardware]

If you look deeper you will probably also find utilities for both PC and for the ST which can take a single TOS image file and spilt it up into 6 x EPROM-ready files. Again, I'm unable to look just now but if you ask on one of the aforementioned forums, someone will probably be able to point you in the right direction.

[ortek_service]

Originally Posted by SiriusHardware

The original Atari ST disc format was similar to, but not the same as, the DOS format, so discs written by early version TOS can not be read from or written to by DOS and vice-versa.

From TOS 1.04 this changed, Atari STs could read from and write to DOS formatted discs (360K or 720K, according to the drive fitted in or connected to the ST) and PCs with 360K / 720K drives could read from and write to discs which had been formatted in the Atari ST. This made it much easier to exchange files between Atari STs and PCs.

Unfortunately your ST260 is likely to have TOS 1.00, which doesn't have this direct PC DOS disc compatibility.

Bear in mind that the external USB drive you buy will be designed to read / write 1.44MB floppy discs - there are stories which say that such drives don't always work well with 720K or 360K discs, but it is worth a try.

I've just thought, actually - does modern Linux still support floppy drives? My instinct says yes, but best to check before buying any hardware.

More of a problem with external USB FDD's is that many tend to only support PC format disks. So whilst they may support 720KB (and possibly only reading of these?) they may not support different sector sizes / sectors per track etc.
I know many have had troubles with this, but if the Atari disk format is similar to PC (except early FDD's only being S/S - And hopefully not 40T, if they ever did 40T 3.5" FDD's?) then these might work.

I wouldn't expect most flavours of Linux to have removed support for FDD's, as it tends to be for more advanced users than Windows, where M$ seem to keep removing support for legacy hardware in later versions.
Maybe more of an issue is Linux driver-availability for these?

[SiriusHardware]

True, with USB drives you don't usually have low-level control of the heads, track stepper etc which you need to be able to write 'interesting' formats including various schemes used to implement disc protection but I think the standard Atari ST disc format is close enough for a PC drive which can write DOS discs to be able to write 'normal' ST discs.

[nlpe1goo]

I found another Atari mouse and this is fully functioning. So the other mouse is defect and the Atari is functioning now. Perhaps one of the diodes in the faulty mouse is defect. I'll investigate it further later with my scope.
Now I have still one thing to solve... creating a working disk for it.