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Reverse Engineer the Spectre GCR?

Forums > Vintage Atari > Atari ST Line

JustG
New Tinkerer
California
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Joined: Dec 12, 2021
Posts: 62
Likes: 16
Jun 9, 2022 - #1
With all of the amazing projects that have come out over the past few years for our old computers, has anyone considered or is there any effort to recreate the Spectre GCR cartridge? As Mac collector and now a ST owner, this is something that interests me:

Attachments:
en.wikipedia.org [View]
en.wikipedia.org [View]

Kai Robinson
TinkerDifferent Board President 2023
Worthing, UK
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Joined: Sep 2, 2021
Posts: 1,322
Likes: 1,313
Jun 9, 2022 - #2
Well, i've never seen the hardware in real life - but looking at this image, the layout looks simple - the question is, what's on the PAL (there's at least 1 there) and what are the other chips?

Attachments:
spectre-gcr.jpg [View]

JustG
New Tinkerer
California
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Joined: Dec 12, 2021
Posts: 62
Likes: 16
Jun 9, 2022 - #3
I'm now on a mission to find one of these. If I end up with one in my hands it's going to be sent to the right people.

mg.man
Tinkerer
Ardley, UK
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Joined: Oct 20, 2021
Posts: 133
Likes: 69
Jun 10, 2022 - #4
>> Kai Robinson said:
Well, i've never seen the hardware in real life Click to expand...
Mmm... I have - and just a few minutes ago... :)



>> Kai Robinson said:
the question is, what's on the PAL (there's at least 1 there) and what are the other chips? Click to expand...
Indeed. It looks like Dave (Small) and team went to quite a bit of trouble to wipe off the chip markings. Here's the best I could pull off...








Attachments:
20220610_115805.jpg [View]
20220610_120021.jpg [View]
20220610_120513.jpg [View]
20220610_120454.jpg [View]
20220610_120448.jpg [View]
20220610_120412.jpg [View]
20220610_120324.jpg [View]
20220610_120214.jpg [View]
20220610_120125.jpg [View]
20220610_121416.jpg [View]
20220610_120103.jpg [View]

max1zzz
Moderator
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Joined: Sep 23, 2021
Posts: 269
Likes: 673
Jun 10, 2022 - #5
>> mg.man said:
Indeed. It looks like Dave (Small) and team went to quite a bit of trouble to wipe off the chip markings. Here's the best I could pull off... Click to expand...
Are those sanded or have they been painted over? it might be worth trying a little IPA on them

Edit: Looking at the pictures I would guess U8 is the only PAL on there, looking very closely at the picture @Kai Robinson posted I *Think* its marked as a TIBPAL16R4 so hopefully this is unprotected otherwise the equations would need to be recreated by hand

mg.man
Tinkerer
Ardley, UK
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Joined: Oct 20, 2021
Posts: 133
Likes: 69
Jun 10, 2022 - #6
>> max1zzz said:
Are those sanded or have they been painted over? Click to expand...
Sanded or acetone'd off. If you look closely at a few, you can see some sanding(?) marks in the corners of some of the chips.

There does seem to some trace of the original silkscreen on a few of the chips, hence all the different angles.

tomswork
New Tinkerer
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Joined: Oct 25, 2021
Posts: 9
Likes: 4
Jun 21, 2022 - #7
This is the schematics for the gcr let me know if anyone has a the pal code

Tom
Attachments:
ATARI-Spectre-GCR-1.pdf (176.1 KB)

Liked by mg.manandKai Robinson

Kai Robinson
TinkerDifferent Board President 2023
Worthing, UK
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Joined: Sep 2, 2021
Posts: 1,322
Likes: 1,313
Jun 21, 2022 - #8
Porchy / @Bolle / @max1zzz may be up to the task :)

Bolle
Tinkerer
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Joined: Nov 1, 2021
Posts: 55
Likes: 95
Jun 22, 2022 - #9
Worth a try, I've got an old programmer that still does all sorts of PALs. If we get one of those thingies my way I can give it a try (and take a look at manually recreating some code if it's locked)

Unless porchy wants to take a look, figured that might be easier from a shipping point of view.

Nervebreaker
New Tinkerer
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Joined: Jul 11, 2022
Posts: 1
Likes: 1
Jul 11, 2022 - #10
I'm trying to price mine for sale. I won mine by guessing the birthdate of his son but also was a Magic Sac user. I spent a drinking evening with David Small after our mutual friends vouched for me. Lots of hacking stories exchanged
Attachments:
20220711_172936.jpg (1.8 MB)
20220711_172804.jpg (1 MB)

Liked by Javmast3r

Javmast3r
Tinkerer
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Joined: Oct 27, 2021
Posts: 70
Likes: 63
Oct 20, 2022 - #11
Somebody reversed the Magic Sac:

Liked by JustG

Javmast3r
Tinkerer
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Joined: Oct 27, 2021
Posts: 70
Likes: 63
Oct 21, 2022 - #12
We could use the one I linked, they have all the files and gerbers. I could do the 3D case.

JustG
New Tinkerer
California
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Joined: Dec 12, 2021
Posts: 62
Likes: 16
Nov 21, 2022 - #13
I've got very little experience when it comes to ordering boards. I'm very interested in putting one of these together but I'd really need someone to hold my hand through the order process.

Javmast3r
Tinkerer
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Joined: Oct 27, 2021
Posts: 70
Likes: 63
Nov 22, 2022 - #14
I may have the pieces to do one or two kits

tomswork
New Tinkerer
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Joined: Oct 25, 2021
Posts: 9
Likes: 4
May 23, 2023 - #15
Hello Javier I can't follow the link were you able to download the bom and gerber for the magicsac

Tom

Javmast3r
Tinkerer
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Joined: Oct 27, 2021
Posts: 70
Likes: 63
May 23, 2023 - #16
Yes, I made some, still have to burn the ROMS...

tomswork
New Tinkerer
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Joined: Oct 25, 2021
Posts: 9
Likes: 4
May 23, 2023 - #17
>> Javmast3r said:
Yes, I made some, still have to burn the ROMS... Click to expand...
Are the roms 2732 ? Parts do you know I order a set of board from jlcpb

tomswork
New Tinkerer
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Joined: Oct 25, 2021
Posts: 9
Likes: 4
May 23, 2023 - #18
Did some research and it looks like the magic sac uses the macintosh 128k roms so they are 32k by 8 27c256 should work fine now to split a file

Tom

JustG
New Tinkerer
California
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Joined: Dec 12, 2021
Posts: 62
Likes: 16
May 23, 2023 - #19
Still very much interested and tracking this. Glad to see it getting some traction!

tomswork
New Tinkerer
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Joined: Oct 25, 2021
Posts: 9
Likes: 4
May 23, 2023 - #20
This is a schematic for the magic sac it has address lines at thru a14 so it supports 32k by 8 or 27256. Mac 128k or maybe mack 512k roms the parts are all common
Attachments:
magicsac_plus.pdf (43.2 KB)

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