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One Last EPROM


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#26 Nezgar ONLINE  

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Posted Sun Feb 11, 2018 9:14 PM

Oh, I figured 'HCD' is just further evidence that it was an in-house prototype of the 'Home Computer Division'.

Considering the other hacks to that PCB, I'm guessing it's likely the ROM is a normal production OS if they just wanted to fix up the drive to make it functionally the same as a production drive.

#27 DavidMil OFFLINE  

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Posted Sun Feb 11, 2018 10:50 PM

My wife informed me that we have doctors appointments tomorrow so I figured I'd better do this tonight.  So, here is the Dump of the

Tandon ROM chip (2732G).

 

David  

Attached Files



#28 Nezgar ONLINE  

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Posted Sun Feb 11, 2018 11:41 PM

Well, if your EPROM hasn't suffered from bit loss, it's a new one to me. Comparing to dumps I've acquired of Rev J, K, L, and WST, your ROM is least different from Rev J, in four places:

File1=your 1050 ROM Chip.BIN
File2=1050-revJ.rom
 
Compare error at OFFSET 0
file1 = FF 11111111
file2 = FB 11111011
Compare error at OFFSET 3EA
file1 = EA 11101010
file2 = 46 01000110
Compare error at OFFSET 3EB
file1 = EA 11101010
file2 = B6 10110110
Compare error at OFFSET FF9
file1 = 48 01001000
file2 = 4A 01001010

EPROM's erase to FF's (1's), so I would think that if it is suffering from long term bit loss, we'd see random 0's change to 1's. This fits offset 0, but not the other three offsets.


Edited by Nezgar, Sun Feb 11, 2018 11:48 PM.


#29 Nezgar ONLINE  

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Posted Sun Feb 11, 2018 11:50 PM

Oh. EA's are 650x NOP's - maybe disabled checksum for development?
 
This post supports the double NOP disabling checksum, done in the WST ROM, and those bytes compare same with your ROM.... http://atariage.com/...roms/?p=3581252
 

Comparing WSTR5 not support WD2797 no checksum.BIN and 1050 ROM Chip-from prototype board.BIN...
Compare error at OFFSET 0
file1 = F3
file2 = FF
Compare error at OFFSET 1
file1 = E7
file2 = F7
Compare error at OFFSET 2
file1 = CF
file2 = EF
Compare error at OFFSET 3
file1 = DB
file2 = DF
Compare error at OFFSET 4
file1 = 46
file2 = F6
Compare error at OFFSET 1D
file1 = 28
file2 = 38
Compare error at OFFSET 27
file1 = 28
file2 = 38
Compare error at OFFSET 29
file1 = 73
file2 = 71
Compare error at OFFSET 3C
file1 = 60
file2 = 5E
Compare error at OFFSET 4D
file1 = 4F
file2 = 4D
10 mismatches - ending compare

Edited by Nezgar, Mon Feb 12, 2018 12:03 AM.


#30 Nezgar ONLINE  

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Posted Mon Feb 12, 2018 12:47 PM

Before I start a new thread to ask - does anyone have a scanned version of the original install documentation for the ICD US Doubler? I've only found OCR'd/retyped versions online. Surprising since there's scanned docs for many other ICD products. Or maybe original docs are rare since it was so heavily pirated... :P There is one on eBay right now, but it's just a photocopy, not the usual pink cover: https://www.ebay.com/itm/302439408036



#31 1050 OFFLINE  

1050

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Posted Mon Feb 12, 2018 3:25 PM

Can't make heads or tails of exactly what you want,
a color correct photocopy? OCR, typed is out for
some mysterious reason too.

ICD did put it in the SDCS manual, it's all there
except the cover art. Don't recall seeing it as a
standalone manual but why do you need one anyway?

http://www.atarimani...ners-manual.pdf

Minor point, all of DavidMil's posted rom files start
with FF when that byte is not really there. I think
it might be his outdated burner/reader has a bug in it?
It makes the first byte always FF.

#32 Nezgar ONLINE  

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Posted Mon Feb 12, 2018 4:35 PM

ICD did put it in the SDCS manual, it's all there except the cover art. Don't recall seeing it as a standalone manual but why do you need one anyway?

http://www.atarimani...ners-manual.pdf

The purist in me thought it would be nice to include a printout with an upgraded 1050. Otherwise yeah, the content would be the same as the SDCS manual, but that eBay auction is evidence they did make a standalone manual at one point.



#33 _The Doctor__ ONLINE  

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Posted Mon Feb 12, 2018 7:40 PM

Logical thing is to let DavidMil know to re-post the roms with the pre-pended ff omitted... or snip it off your self and post them..



#34 1050 OFFLINE  

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Posted Tue Feb 13, 2018 12:32 AM

Well it's not a confirmed fact and it might be operator
error as in he should be entering the read section
via a different means perhaps. Don't know for sure,
but I have stated that I had something else other
than FF for first byte and Nezgar reports the same
thing.

Too odd, so I post a suspicion I'm having. I'm sure
David's still about and might investigate some. Not
prepended data either just altered to be FF for
first byte and pretty consistent about that so far.

I consider it a minor point still, at least it's
being discussed. My PC burner for example will
try to use the last file of record loaded until I
take steps to load an empty instead which then forces
it to read the actual data that is there. Cursor
might be situated upon byte #0 and one should
arrow up or otherwise take pains to not step on it.
But I don't know his software, I just know mine.

#35 _The Doctor__ ONLINE  

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Posted Tue Feb 13, 2018 1:16 AM

exactly, we all see it, we know it's not correct. We personally don't need to know the reason. He should investigate to find a fix. The posted roms should be replaced because the average bear will just burn the rom and it can be a problem, as they won't more than likely know what to do with it. It might not even be in this thread, or on AtariAge by the time they possess them.

 

I forget what I used to have to pad on one of the old burners. but it's something I remember having to do at one time in my life.



#36 DavidMil OFFLINE  

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Posted Tue Feb 13, 2018 7:00 PM

I will look into it.  Also I can dump them with another burner to see what they look like.

 

David






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