View Full Version : Atari 520st(m?)

June 3rd, 2012, 08:55 PM
I just got my first ST in the mail.

The top plate says 520st,
The bottom says 520stm
The back panel has the holes where rf is supposed to be, but there's nothing there.

What gives?

June 4th, 2012, 04:27 AM
You can check if it has composite video output on pin 2 of the large video output connector, which will probably be more useful these days than an RF output:


The general rule is that if the ST has an RF modulator, it will also have the composite video output, but if it doesn't, it won't. However since yours was maybe built to use RF modulator even if it doesn't have it installed, perhaps it will have the composite output.

July 7th, 2012, 11:43 AM
Sounds like someone put the wrong case bottom with the rest of the parts. You probably have a 520 STf motherboard inside.

Micom 2000
July 25th, 2012, 03:54 PM
I also have among my considerable Atari collection a 520 STf, labelled as an STfm.which to my disappointment didn't have the FM connectors. Perhaps this model was sold at a lower price with the option of buying later a hardware add-on gismo to turn it into an STfm. This confirms my suspicions. I don't believe it was put into another case.

July 26th, 2012, 04:01 AM
I aware only the following models:
- ST
- STf Same as ST, but the floppy drive is integrated (the rest has only external floppy drives) "f" meand "floppy"
- STfm Same as STf, but an rf modulator is added "m" means "modulator"

July 26th, 2012, 09:59 AM
Those are the official models, but like Commodore, Atari seemed to often use what was on-hand when assembling their PCs. I've 3 520's and 3 1040's... some are STF, some are STFM, only one actually has the RF modulator... IIRC, one even had an "unpunched hole" for the RF. Best bet - pop the case, take a look at the board. Quite easy to determine if you've an RF modulator in there :)

September 5th, 2012, 01:04 PM
Hi. Mine (serial no. A1 4009617) is also marked 520ST on the top and 520STM on the bottom. It has a modulator fitted next to the MIDI ports and as far as I know this was a standard, but short lived production model, before being superseded by the STFM with integral floppy drive and PSU.


Micom 2000
September 6th, 2012, 01:28 PM
The first ST had an external power supply and external SS FDD. It was indeed labelled ST520 on top and STm on the bottom. The m stood for a modulator and had an RCA plug so you could hook it up to a TV. Next to that plug was a switch for the channel. Without an internal FDD or PSU it had a shallower depth than the later STs. The serial # of mine is 1029669. The next model was the ST520f, ST1040f, then the first MegaST Models(2 and 4 meg memory and external keyboard), the STe and then the MegaSTE models. If the OP doesn't have the Power brick and external keyboard, he won't be able to use it. Trammel basicly copied the design of the 6-bit Atari 130XE for the ST520 to beat out Amiga on the issuing of an inexpensive 16bit computer.


September 6th, 2012, 07:00 PM
Trammel basicly copied the design of the 6-bit Atari 130XE for the ST520 to beat out Amiga on the issuing of an inexpensive 16bit computer.

It was actually the opposite: Tramiel re-released the 8-bit computers in an ST-style case in order to provide a "family look" to Atari's entire line of computers. However, the 8-bit peripherals (disk drives, printers, modems, etc.) were still carried over from the old XL line for quite a while longer -- to help sell off old warehouse inventory, and also maybe because Tramiel (the eternal tightwad!) initially didn't know if the 8-bit computers would still sell well enough to justify the cost of developing new XE-series peripherals for them.

Micom 2000
September 8th, 2012, 04:53 PM
I'm corrected, the 130XE and 65XE(european version) and the St both came out in 1985 (which I didn't know until I looked it up).so it was likely the ST design came first. Tramiel always maximized profit by selling propriatory periferals which screwed up what would have been the Portfolio II, which Sharp quickly scooped up and issued as the PC-3000 when he dropped the hammer on the designers, who had built it according to his specifications.

September 9th, 2012, 09:42 AM
According to a few articles I was able to find, planning for what would become the Atari ST series began in April 1984, even before Tramiel took over Atari. That was after he left Commodore and founded his own company called Tramiel Technology. Tramiel took over Atari's consumer products division in July 1984, and that is when they began working on the XE series. Both the XE and ST series were officially introduced at CES in January 1985, and the 65XE and 130XE began shipping in May 1985, while the 520ST began shipping in June.

The Atari Portfolio was based on the DIP Pocket PC and didn't have much to do with Atari except for the name -- same as with the Atari Lynx, which was based on the Epyx Handy.