Improved Atari TOS versions available
Most important  things to  know
The history:
First Atari STs were released with TOS on floppy. That was early version of TOS 1.00 - not same as little later TOS 1.00 in ROM.
As everything, OS in ROM has it's advantages and downsides:  advantages: more free RAM since most of code runs from ROM, faster start of computer.
Downside:  updating OS is hard - need to open computer and replace TOS ROM chips with new ones, where new TOS version is.
TOS 1.04 and 1.06 were launched in 1989, and they are very similar. TOS 1.62 is just bugfixed 1.06 (like correcting inproper medium resolution desktop.inf saving) . TOS 2.05 was released in 1991, followed soon with bugfix v. 2.06 - which was built in more Mega STE computers, and of course is what everyone should use - I immediately replaced 2.05 with 2.06 in my Mega STE .

Why improving old TOS versions in year 2018 ?

Short answer would be: because there is lot of it what can be improved, added. Without making them slower, less compatible, needing more RAM and like.
FAT16 filesystem called AHDI was never made enough good - including TOS 4.04 of Falcon. Probably just because DR had no good enough C compiler for 68000 CPU .
Using floppies is more and more problematic.
There are some complete new ideas implemented: like GEM statesaves, multiple Desktop.inf files + AUTO folders - why using boot manager, when TOS can do it better ?

Which TOS versions are improved

1. TOS 1.04 - latest TOS for ST machines.
2. TOS 1.62 - That's actually latest TOS for STE machines.
Now, some will say: 'what about TOS 2.06 ?'  -  yes, that's actually latest TOS for ST(E) . But it's not that simple - you can not put TOS 2.06 in some ST without extra HW logic - because it is longer - 256KB instead 192KB, and is on other addess.
TOS 2.06 was made for Atari Mega STE, but is done cleverly, so can work without any change of it's code on ST, STE, and even with some 'large stackframe' CPU - like 68010-30 . As biggest advantage of TOS 2.06 I see it's comfortable Desktop, with many new features. However, there are downsides too - lower compatibility with diverse SW, especially games.  Uses more RAM for self than TOS 1.xx .
And nicest thing is that we can have both benefits : better compatibility
of TOS 1.xx  and Desktop of 2.06 at once:

3.1 :  Combination of improved TOS 1.04 and 2.06 - using better parts of them - so GEMDOS of 1.04 and Desktop/AES of 2.06 . For STs.
Combination of improved TOS 1.62 and 2.06 - using better parts of them - so GEMDOS of 1.62 and Desktop/AES of 2.06 . For STEs .

4. TOS 1.04 and 1.62 with large stackframe support - what means work with CPUs 68010-68030 . Good for some accelerators.

Note: I did not fully disassemble 2.06, so it's code part (binary) (see above which) goes unchanged in those 'combos' . There is simply no time to do everything, + it was no need for that. Possible address conflicts are solved in ASM sources of 1.04/1.62 . Did not use any C sources.
All those improved version work well on Mega STE - there is code what detects on what HW running, and will perform necessary HW initializations by need (if MSTE extra HW is detected) .

GEMDOS is part of TOS what deals with init. of HW, disk access, filesystem, input handling etc. Including simple text output. And even VDI, Line-A, mouse related code are in that part of TOS .
AES is section what deals with graphic user interface (GUI) - so drawing windows, dialogs, alerts and so on. Desktop is what you see after regular start - all those icons, menus. Contains to code for frequent operations like disk copy, format ....

This is not freeware. This is not some kind of TOS "patch" . Several changes are performed, lot of it is added. Without reassembling with optimizations + some data packing it just wouldn't fit in 192 KB ROM space of Atari ST .
I'm ready to customize it by buyers wishes - of course not all combinations are possible, so it may need some talk, what = time. And we know what time is .

Inevitable legal talk

Main improvements in short:

More efficient work with mass storage - Flash cards, hard disks. Larger partitions (up to 1 GB) and max 30 partitions accessible.

Virtual Floppy - much better than Floppy Image Runner (my creation too) - needs less RAM, faster work, possible to use very large pseudo floppy image files .
More and more problems with floppy disks and drives. Who needs them in 2018, when we can do almost everything from mass storage ? Including playing old games.

New Desktop Icons:


Logo at startup, followed with short delay, when can perform some settings:
50/60 Hz refresh rate, disable AUTO run. Switch black and white colors.
Most interesting is environment setting, like with boot managers, just without need to install and bother with them:
When pressing some of keys 1-9 right after logo appears, it will not load AUTO run PRG file(s), DESKTOP.INF and ACCessories from their regular locations (AUTO dir and ROOT of boot partition). but from special directory BT, what must be in ROOT of C partition (works from floppy too, but there is not so useful), and in it can have 9 subdirectories 1-9, in which need to place files what want to be automatically loaded during boot and AES start, res. change.
So, for instance if place  SOME.PRG (for auto run), DESKTOP.INF and SOME.ACC in  BT\3\  - it will activate them when pressing key 3 after logo appears.  With it, very easy to start with desired resident SW, Desktop layout, ACCessories. If nothing is pressed, it will load from usual locations.  Desktop save will go too in proper subdirectory. AUTO run and ACC needs to be copied in proper folder.

Saving GEM SW states and quick restore of them:
Something better than hybernate. May save state of computer, running GEM program by key combination press, practically in any moment (except disk operation periods) . And later can restore that state with key comb. press in couple seconds.
Time depends from RAM amount in machine and disk speed. Of course, only for hard disks, Flash card. Time may be under 1 sec with 512 KB RAM, and about 3-6 secs with 4 MB RAM (stays not for slow Satandisk).
10 diverse states can be saved in 10 slots by holding down left shift+Ctrl and pressing 1-9 or 0. Restore by holding down left shift+Ctrl and pressing F1-F10 .
This will work only with SW what uses TOS functions for peripheral access and other things. And GEM SW is mostly such.
This, and Virtual Floppy must use very low level mass storage access (normal filesystem is not good for), so there is special driver in ROM TOS. And it is for specific adapter - so basic ACSI (Internal  MSTE adapter, old ACSI-SCSI adapters ...), ICD extended ACSI (UltraSatan, better ICD adapters  ...), IDE adapters. May be for some custom adapers too in future.
And that low level driver may serve for regular hard disk driver - then can autoboot it even faster, with very low RAM usage (combined with improved FAT16).

Short demo of state saves and restore:

Distribution, prices:

Primary way is to ship programmed EPROMs, Flash EPROMs to people. Yes, that means + shipping costs, but for most it is only way . In case of STE replacement of TOS ROMs is trivial, so everyone can do it.  In case of ST it can be trivial too, even if TOS is in 6 chips. I see proper EPROMs are still available.  Combo of 1.04 and 2.06 needs extra logic in ST, as is told above. Some may already having it. If not, HW logic must be added. Or stay at good old 1.04, revitalized :-)
Price depends from EPROM (FEPROM) prices, shipping costs. I expect that it will be about 25-30 Euros total, if shipping inside Eu. Stays for sending 2 EPROMs programmed. In case of 6x 32 Kbyte EPROMs (27256), for older STs it may be little more - I need to order some quantity of such EPROMs online, and actual price + shipping depends a lot of quantity ordered.
That's for single modded TOS version, not custom feature combination. If user wants some specific combination that's plus 5 Euros.

Please contact me in e-mail:
There will be no WEBshop style selling.

Sending TOS image files: yes, possible, but all we know that there are people which want easy money without work. Like those who selling my hard disk driver SW in some tricky ways (supplying it with Satandisk for instance) . So, I will need some guarantees when someone wants images. I have ways to recognize is someone really dealing with EPROM programming. Price is 10 Euros.
That's for single modded TOS version, not custom feature combination. If user wants some specific combination that's plus 5 Euros. Any further modded TOS version + 5 Euros too.

Third way would be running improved TOS from RAM (top RAM for better compatibility) . I add this because someone already wanted such version. I can say that it is possible, I did it already and tested. RamTOS can not deal with this, only with regular TOS versions. However, running from RAM, even if there is 4 MB of it in machine is not same as running TOS in ROM. Some things will not work (well) - like Virtual Floppy, statesaves . And is of course less compatible with some SW.
If someone still insists on it, no problem. Price is 10 Euros.
Please contact me in e-mail:

Here is speed test I made some months ago:

Done on Mega STE, with same UltraSatan, with 2 SD cards with practically same speed.
Test is just copying SUBDIR with 80 very short files to some other SUBDIR on partition.

Regular TOS 2.06 :

Note: it needs min 32 KB for buffers for 500 MB partition.
Almost empty 500 MB partition:
At 8 MHz: 39 sec , at 16 MHz 27 sec

Regular TOS 1.04, 8 MHz for same as above: 38 sec - marginally faster.

Improved TOS 1.04 (without large sectors), DOS FAT16 partition of 1000 MB, almost empty:
No added buffers, only base 2 KB, what TOS creates after boot.

At 8 MHz: 26 sec , at 16 MHz: 17 sec
With 32 KB added buffers:
8 MHz - 25 sec, 16 MHz - 17 sec - marginal improvement, or just in range of test error.

So much for now, features are explained here:
Features, screenshots, YT video link

To be continued ...


    PP,   Dec.  2018.