Atari STFM TOS upgrade

[Anemos]

Hi, question for TOS upgrade on Atari STFM with 1.02 TOS, and motherboad REV.C1
How is easy to change from 1.02 to 1.04 or later .. ?
the roms is 2 chip now, for newest TOS needed more chip or what?
What chip eprom type needed to programing?

The photo of roms..


thanks

[jvas]

Upgrading to TOS 1.04 is as simple as replacing the roms.
Upgrading to higher TOS version needs additional components, since it uses a different address space.

[Petari]

http://atari.8bitchip.info/flashest.php

Flash ROM is of course not a must. You can use old-fashion EPROMs too. Basically, everything is possible with max couple logic chips.
If something is not clear, ask. Forum is for it 

[Anemos]

Thanks for answers ..
Well, the STFM is not main a friend ask,and his want easy way for that..
I think that is working for him? .. > http://www.ebay.ie/itm/Rainbow-TOS-1-4-Atari-ST-STF-STFM-Mega-ST-New-2-Chip-/130579295662?pt=LH_DefaultDomain_0&hash=item1e6721edae

[Petari]

It will work. But I don't see what language TOS is it.  It may be US for instance, and then will have problems with video, as US TOS starts at 60 Hz instead PAL 50 Hz.
Why not programming self EPROMs with TOS version what you like ?  No programmer ? Get some, build some 

[Anemos]

Oh yes.. it must be check the language.. thanks for info..
what eproms type needed and how many pieces ?
also can be write 1.62 or later with out moding on board ?

[Petari]

You need 2x 1Mbit (not byte) . Like 27C1001 .  But they have more pins than ROM chips, so some plus work is required - see page how to solve it with intermedia sockets for instance.

But Flash EPROMs are now cheaper.

1.62 will not work on ST(FM).  Only on STE.

[Anemos]

Thanks petari, plz one more, for 2X1 mega 1.4 TOS needed modification on this board? (first post photo)
or just replace that to the same places ?
also. .the rainbow 1.4 is same to 1.04? 

[Petari]

If you want just to upgrade TOS to 1.04 in machine where is originally 2 ROM chips for TOS, and with EPROMs and not ROMs  then need to follow pin layout on small schematic below text  "No GAL programmer? There is a simple solution:"  . No logic (left side) is needed, so only EPROM connections are interesting. As there are 4 pins more. So, on pins 1, 31 and 32 goes +5V.  On pin 2 goes A17 of CPU - it is closest at W2, point 3 . Pin 2 on EPROM is A16, but adresses are shifted by 1, as CPU is 16 bit, while ROMs are 8-bit. Other pins go normally


Rainbow TOS is actually nickname for TOS 1.04 - so it is same.

[Anemos]

i get it.. thanks for all  Petari

[Anemos]

Unsleep the topic for a little help..
petari i need your ok (correction) if this simple schematic is correct for 32 pin eprom,to STFM



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[qq1975b]

Does this method work with 27C010 or 27C1000 EPROMS or 29F010 EEPROMS?

[Petari]

Well, I always look schematic of particular machine, and pin layouts of EPROMs, Flash EPROMs. Then need to connect proper lines with proper pins.  In some ST machines (mostly older ones) both control signals of EPROMs are used - OE and CE.
By some newer boards, one is connected to GND always. Difference is mostly because they use not UDS and LDS lines - it probably made jumpering simpler. Activating both EPROMs at once, even if only byte read is asked makes no harm.
The whole science here is to connect properly CE and OE and +5V on EPROM, Flash EPROM.
27C010 or 29F010 is practically same. 27C1000 may have little different pin layout. Just Google for it, and will see that even not all 27C1000s are same. By some OE is at standard place, by some is on pin 2 ( I guess that it is rare case - some programmers support it not) .

[qq1975b]

I have tried the schematic posted before with TOS 1.04 SP on a Mega 4 but it didn't work. Just blank screen with a very soft yellow border 

[Petari]

Give me exact type of EPROMs you use , and I will give you solution.
Some work on jumpers (soldering pads)  is needed too .