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Looking for Atari 850 ROM


JAC!
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Hi there,

 

I bought a working 850 and a broken one and would like to fix the broken one. But my E-PROM reader cannot read the first half of the original ROM as it is not EPROM. Can somebody please provide the 850 ROM?

 

Thanks, Peter/JAC!

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Thanks guys. Your both files are identical and the first 2k match my dump (rest cannot be read by my chinese programmer, but nevermind). Since I have a working original mask ROM I can continue with this information.

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  • 2 months later...

Since my self-made EPROM-2-ROM adapter didn't work, I ordered this one

 

http://www.go4retro.com/products/23xx-adapter/

 

and today I finally managed to try it out - and it rules. Boots like a charm, OPEN #1,4,0,"R1:" READY.

Now I have 2nd working 850 ROM to track down the issues in my 2nd (broken) 850 board.

Thumbs up for Retroinnovations!

 

post-17404-0-90533600-1454257711_thumb.jpg

post-17404-0-62345600-1454257715_thumb.jpg

 

 

 

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  • 2 weeks later...

There were a few rom's for the 850... some transferred data flawlessly some did not, some would not boot properly other would boot everytime.... what I wanted to have done years ago... was to have all the different roms tested and one rom containing the best of all of them created.

I only ever had one 850 that ran perfectly and that was way way way back..... it wasn't until I read some article in a magazine I found out why two of my later 850's weren't perfect... it came down to the rom.... more lost knowledge but I am sure if everyone compares roms we can figure it out again!.... in fact how about an upgrade to get the 850 doing sio as fast as it can as well as the regular serial ports.... I had a modified one that was lent to me when this was all serious computing and hated returning it to the owner.... never occurred to me to copy all that was changed at the time... just knew I loved it....

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I don't remember for sure, but I've looked at the 850 ROM and I think I saw a way to run arbitrary code out of the 850 RAM using a special SIO command. It may be possible to dump an 850's ROM without having to open it. You only have 16 bytes or something, though. I'd have to look at it again.

EDIT: C/Ped from the 850 ROM source

;       MISC I/O:
;
;               TEST (RS232 PORT 1 ADDRESS; AUX1=LLLLLLLL)
;                       LLLLLLLL=BYTE COUNT
;                               WILL RECEIVE LLLLLLLL BYTES THEN JUMP TO IT
;                               IN BUFFER AS TEST CODE

and then later:

        CMP     #'              ; (BLANK) LOAD & XEQ TEST?
        BNE     *+8             ; BR IF NOT
        DEC     RTEST           ; SET TEST FLAG
        LDA     BUFE-1+2        ; AUX1=BUFFER LENGTH
        BNE     RSWRT

It seems like you probably have at least 64 bytes for whatever code you're uploading. I wonder if this stayed in every ROM version?

Edited by Joey Z
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  • 1 year later...

You may want to send a message to NF6X, he has a friend that has done some really cool modifications to the 850 ROM.

 

David

 

 

Hi! I was unaware that I have a friend. Who is this mystery person? I'm still an Atari 8-bit noob, and I don't think I have heard of 850 modifications yet. I have an 850 that I haven't done much with yet.

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Hi! I was unaware that I have a friend. Who is this mystery person? I'm still an Atari 8-bit noob, and I don't think I have heard of 850 modifications yet. I have an 850 that I haven't done much with yet.

 

Sorry man. I don't know how your name popped into my head. I suspect that it has something to do with old age. I meant to say MetalGuy66. A very interesting young man

who lives hear in Texas.

 

David

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Anyone have any idea of how many versions there are? I popped both of my 850's open and they both say CO12099-3. Which per Atari means rev. 3.

 

David

That doesn't mean the rom code is revision 3, it just means the chip is from the third run of that same part number that Atari ordered. The code may or may not be the same as the -2 or -1 part.

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That doesn't mean the rom code is revision 3, it just means the chip is from the third run of that same part number that Atari ordered. The code may or may not be the same as the -2 or -1 part.

 

I've been hearing that statement for years and I have to say it is only partly true. When A manufacture such as Intel makes a batch of chips that it will sell

to anyone that wants them, they do put a batch code after the part number. But when a company such as Atari has the part made for them, the alphanumeric

digit after the part number is quit often the rev. level. The attached file is from the Atari 850 Interface Module Field Service Manual:

 

 

David

post-47264-0-84985700-1494439534_thumb.png

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Absolutely don't buy that as a generalized statement - look at any of the photos of assembled Atari 6502-based game machine and computer boards, from the earliest Heavy Sixers to the last XE's - every one of the main system chips has a hyphenated batch code following the Atari C0xxxxx part numbers - 6507, 6502, 6520, 6532, TIA, CTIA/GTIA, ANTIC, POKEY, BASIC and system ROMs, MMUs and Freddie ... all have hyphenated part numbers. They are production batch codes, nothing else.

 

Those codes MAY reflect a change in the underlying circuitry, but in more cases than not they cannot possibly.

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okay this happens all the time... to best of my 'membrance... batch-hyphen-part part hyphen rev and batch hypen part hyphen rev.... and in true Atari fashion..... technical note about the numbering when a certain manufacturer/supplier had their own way of doing it for whatever reason or confusion....both internal to Atari or external to whoever produces the chip... the best readily available way to know is the field service manuals and service bulletins...

Edited by _The Doctor__
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I'm not saying that the structure of the chip changed, I'm saying that the software burnt into the chip changed. I also worked for Compaq in one of

the board shops for four years, we would always have to verify the ROM rev level before distributing the chips to the line. This was also for the benefit

of the field repair technicians. So I'm telling you from 10 years of experience with ROM chips in the 80's and 90's that it was MORE than just a batch codes!

 

David

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okay this happens all the time... to best of my 'membrance... batch-hyphen-part part hyphen rev and batch hypen part hyphen rev.... and in true Atari fashion..... technical note about the numbering when a certain manufacturer/supplier had their own way of doing it for whatever reason or confusion....both internal to Atari or external to whoever produces the chip... the best readily available way to know is the field service manuals and service bulletins...

 

You are right, service manuals and especially service bulletins supersede everything.

 

David

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I'm not saying that the structure of the chip changed, I'm saying that the software burnt into the chip changed. I also worked for Compaq in one of

the board shops for four years, we would always have to verify the ROM rev level before distributing the chips to the line. This was also for the benefit

of the field repair technicians. So I'm telling you from 10 years of experience with ROM chips in the 80's and 90's that it was MORE than just a batch codes!

 

David

 

And I'm telling you from opening up and playing with Atari game consoles and 8-bit computers for the past 35 years that most of the time, they are inventory control batch codes, NOT product revision levels. I invite you to spend a few minutes with the Jan 1984 Atari Information Systems Item Master List posted on Atarimania (all 108 megabytes of its scanned, wide-column dot matric glory) and get back to me. They did NOT generally use the hyphenated portion of their internal part numbers to indicate any sort of revision level across their product lines.

 

For instance even here in 1984, after the 850 has gone out of production, Atari did not refer to any hyphenated part number in reference to the 850 rom.

 

post-30400-0-20984400-1494460962_thumb.png

 

For reference, the second column there is specifically there for revisions, not the C0xxxxxx part number itself.

 

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Your not reading the revision level like most engineers..... the revision level is for the assembly not the part.... I could spend years explaining why over time certain aspects don't jive on the sheet as it morphed over time. I hope this makes sense...... as a general rule the revision level is for an assembly, sub assembly or complete unit.. the part used in the unit may or may not show the revision of the part listed. The part is generally listed in it's generic form as it will work in many assemblies and usually the latest revision on hand. The specific different parts if there is a valid reason to do so will be shown with a hyphen and the difference may be noted in description area or technical service bulletin or field service manual... That's the gist of it ask any Atari engineer.

Edited by _The Doctor__
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And I'm telling you from opening up and playing with Atari game consoles and 8-bit computers for the past 35 years that most of the time, they are inventory control batch codes, NOT product revision levels. I invite you to spend a few minutes with the Jan 1984 Atari Information Systems Item Master List posted on Atarimania (all 108 megabytes of its scanned, wide-column dot matric glory) and get back to me. They did NOT generally use the hyphenated portion of their internal part numbers to indicate any sort of revision level across their product lines.

 

For instance even here in 1984, after the 850 has gone out of production, Atari did not refer to any hyphenated part number in reference to the 850 rom.

 

attachicon.gif850rom.PNG

 

For reference, the second column there is specifically there for revisions, not the C0xxxxxx part number itself.

 

 

As you requested I downloaded the whole 108 meg file (took over an hour), and I now understand your confusion. This is a Engineering Hardware Master list.

As the Doctor said one part can be used for many applications. If you'll notice to the right side of the page is a column marked ECN Engineering Change Number.

This is a hardware listing of parts. It has nothing to do with software rev levels on the chips. Case in point, look up C012499 and C014599. Your list doesn't show

any revision levels like A or B. But you try and mix a rev C012499A and rev C012499B chip and see if you 800 will boot. And yes, as in all big companies, this

different style of marking rev levels comes for one hand (a contracted company) not knowing what the other hand (another contracted company) is doing.

 

But I still agree with you for general purpose chips sold to electronics companies around the world. They are just batch numbers.

 

David

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