The correct memory type is 30 pin SIMMs, with or without parity, capacity being either 256Kb or 1Mb. The minimum speed of 256Kb SIMMs is 150ns and 120ns for 1Mb SIMMs. It is best not to mix different SIMM types. They must be installed by pairs in slots 1 and 3, then 2 and 4 (from back to front).
Atari STEs are originally equipped with either 2 (520STE) or 4 (1040STE) 256Kb SIMMs that can be replaced by 2 or 4 x 1Mb SIMMs.
Because of a bug in TOS, STEs will not recognize a 2.5Mb configuration (2x256Kb + 2x1Mb) without a small bootup program like silkboot2e or simmfix. These can be found on most FTP sites (see section 2.2.3), but are quite unreliable.
A way to avoid the soldering and memory limitations is to use a special memory expansion board that replaces the original memory banks with standard SIMM sockets. There are several such solutions available like the Marpet Xtra Ram board or the Aixit 10Mb expansion board. Look for Atari related companies on the Atari web pages (see section 4.3).
DIY conversions require serious soldering skills, and are not for the faint hearted. Descriptions of such modifications can be found below:
However recent developments have seen third party expansion boards that allow going beyond this limit. The Magnum-ST board from Woller+Link in Germany allows up to 16Mb on a plain ST/STF (not STE). TOS versions below 2.06 will not deal with more than 4Mb, so either a TOS upgrade or MagiC (see section 2.5) is necessary.
Woller + Link
These are the only hard drives that are directly "plug'n'play" compatible with the Atari ACSI/DMA port on stock STs.
Atari SH drives have the advantage of being made up of an ACSI to SCSI host adapter connected to an Adaptec 4000 SCSI to MFM adapter that is attached to the drive. It is therefore sometimes possible to adapt these drive to use SCSI drive mechanisms. This is not the case for Megafile drives.
It is possible to expand Megafile drives by adding a second drive mechanism inside the case. Here are explanations on how to do this:
WB Systemtechnik (Link'97)
The largest drives the Mega STE internal SCSI interface supports are 1Gb. Anything beyond that will be wasted. This interface also does not support parity, therefore you should disable it by using the jumpers on the drive.
A parity generator for any host adapter that does not natively support parity can be easily built by following the instructions below:
Mario Becroft's adapter is quite similar but is available for both STF or STE models and includes a TOS 2.06 upgrade, which is required if you plan on booting on the IDE drive.
Instructions to build your own DIY interface also exist, but should only be performed by people with a solid knowledge in electronics, soldering and programming GAL chips.
Mario Becroft's hardware
DIY IDE Interface
Just a general note: You can partition IDE drives as much as you like, but do not format them. Some of them will not recover from a "low level" format.
Zip Drive FAQ
Be aware also that CD ROMS and ZIP drives use parity, so you must have a parity enabled SCSI adapter or perform the following modification to allow parity on a non-parity host adapter:
PC drives can be used as replacement drives, only nowadays it is difficult to find 720K drives. You can however use just about any 1.44Mb HD drive as these will perform perfectly well in DD 720K mode. Nevertheless, you have to be aware of the following:
Hallvard Tangeraas' instructions on how to use a Sony drive in an Atari.
Force Media Change
How to modify a Mitsumi drive for the Atari.
Hallvard Tangeraas' instructions on how to use a Sony drive in an Atari.
All the above modifications are also valid if you are planning on upgrading an external drive. You will still have to modify the drive mechanism, and you will still have to modify the ST's motherboard.
Lots of information on the subject can be found at the following page too:
The Atari Hardware Hack Page
A problem lies, however, with the recent appearance of cheap printers "Optimized for Windows 95". These units actually lack hardware, making them rely on require Windows95 to run. They will also not work with a Mac or Unix box, so be careful when you buy.
Atari became famous in the DTP for offering the first cheap laser printers. This was done by using the computer's RAM instead of having built-in memory. The SLM laser printers therefore require at least 2Mb of RAM to run. They also attach to the ACSI/DMA port, which means that they cannot be connected to a Falcon. A Falcon/SLM adapter, called the Heatseaker, did exist but never got to the market.
Properly written programs will use the GDOS standard, allowing use of proportionnal fonts and standard drivers.
To run GDOS on your computer, there are several solutions. FontGDOS is the latest freeware GDOS implementation from Atari, but is slow and handles only bitmap fonts. SpeedoGDOS and NVDI are both commercially available and fully maintained, and handle both bitmap and proportional fonts. NVDI is also a very efficient screen accelerator. Basically, if you plan on using a printer, you should consider obtaining NVDI.
NVDI 5.0 - Systems Solutions page
The Deskjet Home Page - Printing support for Atari
A PC serial mouse can be connected directly to the serial (modem) port. There are two drawbacks to this. Firstly, on a machine with only one serial port it prevents from connecting anything else (modem, extra midi ports...). Secondly, you will need to load a serial mouse driver such as Genmouse, which can be found on your favourite FTP sites (see section 2.2.3). The problem is that, being an auto folder program, it will obviously not run with autobooting programs such as games.
A PC mouse can be attached to the Atari mouse connector, but this needs a complicated adapter board, such as those described here:
Mario Becroft's Atari/PC keyboard and mouse adapter
Some Amiga mice have a little Amiga/ST switch allowing them to be used on an Atari, the only difference between the two being two swapped wires.
Although old PC Bus mice are now probably as difficult to get as ST mice, instructions on adapting one for use on an Atari can be found here:
If all else fails, you can always use the Alt + Arrow keys trick (Alt + Shift + Arrow keys for pixel scale movement, Alt+Clr/Home for left click, and Alt+Insert for right click) as a lifesaver, but that's hardly a practical solution in the long run.
Erratic mouse behaviour is sometimes caused by a faulty connector. The mouse port connections under the keyboard, are subject to stress when there is continuous plugging and unplugging of the mouse (to connect a joystick for example). A remedy for this is to take apart the ST and touch the solder joints that connect the mouse connector to the keyboard PCB with a soldering iron, just to restablish a good contact by slightly melting the solder.
One of the weak points of the Atari ST is the keyboard. First of all, the standard ST/STF/STE/Falcon has a very "squishy" touch. There are solutions to this, such as the famous "TT keys" rubber cups that you are supposed to put under each key to give it a more pleasant feel.
The Mega ST,Mega STE and TT keyboards were much more professional and can be easily adapted to the other machines. For this, but also because the best way to repair a broken keyboard is to just replace it, you might want to follow the instructions below.
A common, and quick fix to this is the famous 4 inch drop, and it goes like this:
Of course, another (more professional) option is to take apart the machine and reseat all the chips by hand.
Atari ST Internals
ftp://ftp.leo.org/pub/comp/os/atari/hardware/netzteil.zipMany people ask for information about the Atari proprietary port pinouts. These can be found in the computer manual, but if you don't have one around, this page has pinout information for just about any connector in the electronics industry, including all the Atari ports, standard VGA connectors and SCART/Peritel sockets.
Atari ST Quick FAQ - v2.9a - firstname.lastname@example.org