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Reverse Engineering the Macintosh SE PCB & Custom Chips for 1:1 reproduction


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I have enough spare board/parts to probably put together a working one of these. We would have to build a parts list for all those odds and ends that we don't really know what the heck are (or, in my case, have no training to know what they are).

 

Have you nailed down how much one would cost?

Edited by LaPorta
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Well, most passives are about £30 roughly guesstimating - refer to post 1 to see what you should salvage or have to buy new. You can get 338-6523's (they're just Rockwell branded MOS/CSG 6523 TPI's) for about £5 each, the 26LS chips are £2, the other logic is anywhere from £1.20 to £3 depending on vendor. SIMM sockets can be salvaged, but i recommend buying new from the link i posted on page 2. 

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I am both up for this and in the UK (I gathered from your spelling of 'arse' in the first post you might be over this way, and the £s confirm it), if that makes shipping of boards easier?  I have a dead SE board that has suffered a mild battery explosion and I think all the chips ought to be salvageable.

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Oh, and:

 

10 hours ago, Kai Robinson said:

the only value i cannot find, is R48

 

Here's a photo of that area on my board, though my main connector is labelled J11 (do we have a different board revision?)

 

61608164094__42C5AFC0-495B-47A6-991A-B19A35445382.thumb.JPG.d42d11baab3603308e9a33fb844597c5.JPG

 

If my eyes do not deceive me, that's 3.3k?

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J11 is aux battery header. J12 is the main connector - look under the silkscreen for the 53C80 SCSI chip, you should see it. However, you're quite right, that *IS* a 3.3k! Which makes sense, since all the other pullups are rated for that, too. 

 

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8 hours ago, Kai Robinson said:

J11 is aux battery header. J12 is the main connector - look under the silkscreen for the 53C80 SCSI chip, you should see it

You're quite right, apparently I just can't read.  Ta :-)

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On 7/9/2020 at 11:22 PM, Kai Robinson said:

J11 is aux battery header

Actually, I'm 99.8% sure that's for the speaker?
 

This is a very incredible project!  If anyone ever does one for the SE/30 (probably much more ambitious, but technically not much harder than this, I'd suppose?  At least better schematics exist for it?), I'd consider giving one a try, as I have several boards which, if I haven't sold them all, I could salvage custom chips off of.

 

If there were a way to do it non-destructively (there probably is), I suppose one could even "borrow" the custom chips from a working board as well for testing purposes, yes?

 

c

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Well I can do the board - but i need one desoldered completely. it's possible to buzz via's etc for ground or +5v connections, so you dont need to sand a board, but using a few dead boards is a better plan than wrecking a working one. Plus i only need to salvage certain chips like the 26LS and anything Apple custom. 

For all testers of this initial batch - i forgot the GND and +5v connections for the disk and serial - DOH! For some reason i skipped over them, it's fixed in the latest Gerbers, but the prototype batch will need these connecting - nothing major, just solder bodge wires and bridge pins for the SCSI - should see from these images where the GND and +5 connections are - light brown is +5v, dark brown is GND. 

 

forgottenground1.jpg

forgottenground2.jpg

forgottenground3.jpg

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@LaPorta Yes, standard Gerbers - once these boards are tested, if they work OK, then i'll put them up in a Tindie store to allow people to buy single boards off me, with a little markup so i can recoup the development costs of the board - after that, i'll release the Gerbers for all to make and move on to the SE/30, Classic or whatever else people want me to make next...just need two or three dead PCB's and a copy of the schematics and i'm all good to go :D

 

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The SE/30 is probably the one most in need of a new PCB though it is more complex than the basic SE and would require a lot of SMD skills but who knows.  Maybe with the right stencil, paste, and reflow oven it can be streamlined.  

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9 hours ago, maceffects said:

The SE/30 is probably the one most in need of a new PCB though it is more complex than the basic SE and would require a lot of SMD skills but who knows.  Maybe with the right stencil, paste, and reflow oven it can be streamlined.  

At least it doesn't use any BGA stuff!

 

9 hours ago, Trash80toHP_Mini said:

Amazing, love your work!

Definitely seconded 10,000%!!!

 

c

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Have at it for 1:1 repro enthusiasts, again, LOVE your work!

 

< tangent >

But for the SE/30 project, I think we need to make a few upgrades and provision for a bit of modularity. @maceffects with a noodge here and a cutaway section there, an SE/30 board will fit in an unmodified Portable case along with your crazy new Vidcard running a 10.1" 1280x800 RPi-inexpensive panel. That'll make a much sexier MacColby SE30! Without doing the cutaway hacking, it'll still fit and look hella fine in your clear case. Methinks there are even more dead/irreparable Luggable boards out there than the SE/30 variety and I doubt anyone throws away that gorgeous display case. :approve:

< /tangent >

 

 

Edited by Trash80toHP_Mini
apparently I can no longer type or spell.
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Next up, we can come up with a reproduction analog board that contains all the circuitry needed to drive a modern LCD, then, with maceffects' clear case, we can have a 95% reproduction SE or SE/30!  (we could get this pretty close to 100% if we can figure out how to clone the custom Apple ICs or somehow re-implement their functions without salvaging them from dead boards).

 

8 hours ago, Trash80toHP_Mini said:

< tangent >

But for the SE/30 project, I think we need to make a few upgrades and provision for a bit of modularity. @maceffects with a noodge here and a cutaway section there, an SE/30 board will fit in an unmodified Portable case ... Without doing the cutaway hacking, it'll still fit and look hella fine in your clear case. ...

...

< /tangent >

That would be interesting.  While you're at it, rework the power supply circuitry so it can run without a battery, if need be, and have the redesign be implement-able on an otherwise stock Portable LB (for those fortunate enough to have one that by some miracle still works).

 

c

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Another vote for the SE/30 next! I have two SE/30s that I shoddily recapped, and the boards aren't in the greatest condition, so now that I have better soldering skills, I'd love to give my two SE/30s fresh boards, with all non-proprietary/unobtanium ICs and components replaced with fresh ones. Ensuring I'll never add leakage prone batteries and capacitors, those boards will likely outlast the originals!

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10 hours ago, Trash80toHP_Mini said:

But for the SE/30 project, I think we need to make a few upgrades and provision for a bit of modularity

"need" is a strong word here :-) I'd suspect it would be a lot easier to muck around with the board after the event if you know you're starting from a working layout and schematic.

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8 hours ago, Daniël Oosterhuis said:

Another vote for the SE/30 next! I have two SE/30s that I shoddily recapped, and the boards aren't in the greatest condition, so now that I have better soldering skills, I'd love to give my two SE/30s fresh boards, with all non-proprietary/unobtanium ICs and components replaced with fresh ones. Ensuring I'll never add leakage prone batteries and capacitors, those boards will likely outlast the originals!

Ha! The idea of a completely non-Apple SE/30 is great. Let's keep our SE/30s running indefinitely...

 

As part of the Classic II gang gang, though, I'm obliged to cast my vote for the Classic II... although it's got custom ASICs out the wazoo, so it'll be harder to do. Oh well, SE/30 it is.

Edited by rplacd
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8 hours ago, rplacd said:

... all you need to do then is create your own internal chassis and boom – a completely non-Apple SE/30!

You're forgetting the proprietary Silicon on the board, very Apple that.

 

8 hours ago, cheesestraws said:

"need" is a strong word here :-) I'd suspect it would be a lot easier to muck around with the board after the event if you know you're starting from a working layout and schematic.

We've already got a cleaned up version of Apple's schematic ready for mucking about a bit from a ground up build. Has it been checked against the Bomarc schematic? I need to get at least the memory page of that version.

 

Don't get me wrong, I love the process of 1:1 repro work from an existing PCB and mucking about with it. That's really the only PCB "design" I've done, right down to sanding off the layers of a complex later 90's PCB, albeit the very small, PCMCIA/I/R daughtercard for the 1400 030 Bus.

 

I want to see what @techknight and the FPGA/CPLD boffins can come up with in terms of simplification/parts count reduction and hopefully a bit of modularization of Lthe ogic Board's block diagram. Two approaches, one from the top and one from the ground up happening concurrently should be beneficial to both projects I'd think.

 

8 hours ago, CC_333 said:

 

10 hours ago, Trash80toHP_Mini said:

< tangent >

But for the SE/30 project, I think we need to make a few upgrades and provision for a bit of modularity. @maceffects with a noodge here and a cutaway section there, an SE/30 board will fit in an unmodified Portable case ... Without doing the cutaway hacking, it'll still fit and look hella fine in your clear case. ...

...

< /tangent >

That would be interesting.  While you're at it, rework the power supply circuitry so it can run without a battery, if need be, and have the redesign be implement-able on an otherwise stock Portable LB (for those fortunate enough to have one that by some miracle still works).

 Thinking PicoPSU/Plugged in only at first. After that a 24v battery pack that would match the three hour battery life of the MacColby SE30 might be possible?

 

Enough of this tangent! I'll do some doodling in AI and start a new hacks thread about my SE/30 Portable notions if anyone's interested?

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Someone needs to send me two or three dead SE/30 boards so i can do a 1:1 repro - but yes, the schematics are available for this, at least. From the Sprint Layout, i'm going to import each layer as a BMP into KiCAD and then potentially backport it into a schematic :D

 

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8 hours ago, Kai Robinson said:

Someone needs to send me two or three dead SE/30 boards

I have one of these I'm quite happy to drop into the post for you.

 

8 hours ago, Bolle said:

How are you going to scan the internal signal layers on the SE/30 logicboard for a 1:1 repro?

Curious about this, too

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