6 chip TOS

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Methanoid
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6 chip TOS

Postby Methanoid » Sun Feb 11, 2018 5:31 pm

I have an ancient but functional 520 STM. Its got a (fault so removed) 512k Ram upgrade and 6 chip TOS 1.00 but with zero pads for upgrading to 2 chip TOS.

Rather than make life difficult with bending pins and adding OR gates etc.. is there an easy guide I can pass to my friend-with-Eprom-burner to burn me a 6 chip TOS set?

Is TOS 1.04 the best I should fit for an old ST?

My mobo has different labels for the chips to others I can find so I need to know how we split the image into 6 chip images and then which chip goes in which socket, please

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Re: 6 chip TOS

Postby Zippy » Mon Feb 12, 2018 1:19 pm

If you're stuck you could dump the 6 chips you have and compare them to the single part image for TOS 1.00 and work out from that how to split the TOS 1.04 image for the 6 chips. If the device programmer software is any good it should have options for loading data from an offset and specific length in the file without even having to split the file at all.

There's some more info here:

http://www.atari-forum.com/viewtopic.ph ... 9&start=25

but I'd mark and dump the existing 6 chips to be 100% sure the new ROMs will be mapped correctly.

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Bama
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Re: 6 chip TOS

Postby Bama » Tue Feb 13, 2018 3:30 am

I think we have an Atari App to split the TOS files. Maybe on Ppera’s website????

Edit:

Here is his posting.

http://www.atari-forum.com/viewtopic.php?t=13772

Updated hyperlink to his most excellent utilities:

http://atari.8bitchip.info/astopensw.php
Last edited by Bama on Tue Feb 13, 2018 12:49 pm, edited 1 time in total.
:-)
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Re: 6 chip TOS

Postby ranix » Tue Feb 13, 2018 4:45 am

I think tos 1.04 is good for an old ST, it's what I've been using. I have a 6-chip 1.04 TOS set I got off Ebay for a song. I've swapped it out with the Exxos fast TOS upgrade (which isn't working perfectly for some reason, but that's another story).

iirc I had to ship my TOS set from the UK so it will probably be cheaper for you

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Re: 6 chip TOS

Postby ScottChi » Sat May 19, 2018 1:28 am

Hi, would it be possible to get an update on how this went?

I have what appears to be an identical 520STM, made for the US market. It pre-dates having the RF modulator, and appears to have TOS 1.0. The "About..." dialog says "GEM (c) 1985".

I'd like to find a 6-chip US TOS 1.04 for it, if available. It's been many years since I knew anyone with a ROM burner.

Scott C.

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Re: 6 chip TOS

Postby troed » Sat May 19, 2018 8:35 am


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Greenious
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Re: 6 chip TOS

Postby Greenious » Sat May 19, 2018 1:48 pm

If you are US based you might want to check out Best Electronics.

http://www.best-electronics-ca.com
Updated my guides as of june 28th, 2016. Check'em out and feedback!
viewtopic.php?t=5040

ScottChi
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Re: 6 chip TOS

Postby ScottChi » Sun May 20, 2018 1:53 am

Thanks Greenious. I'll check with them.

I found 6-chip TOS 1.04 on B&C ComputerVisions here: http://www.myatari.com/ataristh.txt

It says "ICS006 TOS 1.4 (6 CHIP SET) 35.00". Looks like it might do the trick, but it doesn't say what ROM's were used. Above the section it says "Emulate your Atari on an IBM with Gemulator see PC section." It occurs to me that I could just call them and ask though ;-)

Thanks much,

Scott C.

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Re: 6 chip TOS

Postby 1024MAK » Sun May 20, 2018 9:19 am

Get a piece of card. Write a story on it that takes up at least a few paragraphs.
That's how the CPU sees it in memory.
Now cut the card in half so you have left and right pieces of equal size.
That's how the data is stored in a two ROM configuration. This is the low byte and high byte data (as the CPU bus is 16 bits, but the chips used are only 8 bits wide.
Now cut each left and right piece into three, you should now have six pieces of card. That's how the data is contained in a six ROM configuration.

On various web sites, you will find files with the TOS data in any of these configurations. The single large files are often for use in emulators and are in the format of a ROM dump from a working system (copied by the system CPU to RAM and then to disk).

Sometimes these files are split into more than one file.

You may also find 'ready to burn' files with the TOS data split up ready for a programmer to 'burn' to a EPROM chip.

There are, as said above, utility programs that will split ROM files. Or combine them.

Mark
Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (nearly forgot the Psion's)

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Re: 6 chip TOS

Postby ScottChi » Mon May 21, 2018 1:51 am

Hello Mark,

I understand the subject fairly well, and have already had my hands on a lot of computer hardware, software and firmware. For this effort, buying preprogrammed EPROMs is the most effective solution - as long as they work.

Respectfully,

Scott C.

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Re: 6 chip TOS

Postby ScottChi » Sun Jun 10, 2018 2:44 am

For anyone following this thread who is attempting to install the 6-chip Rainbow TOS (1.04 / 1.4) upgrade, here is the correct cross reference for the TOS 1.0 original ROMs.

CO26160 ST U.S. TOS 1.0 256K (H2) ROM
CO26161 ST U.S. TOS 1.0 256K (H1) ROM
CO26162 ST U.S. TOS 1.0 256K (H0) ROM
CO26163 ST U.S. TOS 1.0 256K (L2) ROM
CO26164 ST U.S. TOS 1.0 256K (L1) ROM
CO26165 ST U.S. TOS 1.0 256K (L0) ROM

This list is taken from the Atari TOS components list on the Best Electronics website located here: http://www.best-electronics-ca.com/custom-i.htm

All you need are the H2/H1/H0/L2/L1/L0 markings on the TOS 1.4 chips in order to swap them out. They may be marked HI-0, LO-2, etc. instead of H0 and L2.

I installed them incorrectly at first, because my initial web search took me to the diagram attached at the top of this message thread: http://www.atari-forum.com/viewtopic.php?f=15&t=23459&start=25

If you compare the component numbers and their H# and L# numbers in the listing above to the ones in that diagram, you will see that they are marked differently. Chip 26160 is listed above as H2, not L2 (and so forth).

When I used the diagram in that thread to match up the chips, my 520ST booted to a blank white screen and did not read the floppy disk at startup.

When I used the list above to identify the chip locations, the system booted normally and displayed the Rainbow TOS banner in the "About..." dialog.

Just FYI. It's quite enjoyable to have upgraded my very old ST to a somewhat less very old ST.

Scott C.

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Re: 6 chip TOS

Postby tzok » Sun Jun 10, 2018 10:19 am

The L/H mix has to do with word notation in variuos CPU... MC68000 is a big endian CPU, and thus the byte order is swapped (more significant byte first). This is only a byte order in the word, bits in bytes are in usual order for either architecture. So when preparing a Lo part of the TOS image you have to actually choose a High Byte in the programmer (as they usually assume little endian a.k.a. Intel notation). So on the schematic the L ROMs hold the lower addresses, but from the CPU point of view, they hold more significant bytes, and thus are marked H ;)

And some interesting observation - this is TOS 1.0 UK:
U2: CO26160-001 ST U.K. TOS 1.0 256K (H2) ROM
U3: CO26244-001 ST U.K. TOS 1.0 256K (H1) ROM
U4: CO26245-001 ST U.K. TOS 1.0 256K (H0) ROM
U5: CO26163-001 ST U.K. TOS 1.0 256K (L2) ROM
U6: CO26246-001 ST U.K. TOS 1.0 256K (L1) ROM
U7: CO26247-001 ST U.K. TOS 1.0 256K (L0) ROM

The "first 1/3" is the same as in US...


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