Motherboard Schematic
Alethia Tiell
Thanks but on Page 62 , it is just a component diagram. it is not a schematic. I am looking for a service level diagram to help me find out the fault on the motherboard. Most companies do provide such schematic.
Having the schematics available in KiCad is going to be incredibly useful. I've wondered about this many times, when I was working with the old schematic PDFs - why we don't have a proper electronic variant, which would help a lot with searching/analyzing.
Maybe consider contacting him directly - and offering him your R0 version. He would certainly credit you for the work. It would be really nice to have all these schematics in one place, rather than scattered across different projects.
I used the "baldengineer's" Apple II Plus as a starting point and have been in contact with him since I found the first issue. (A transistor was incorrect.) I also let him know about the Apple II R0 files I posted shortly after I posted them. (I figured it would be only fair since I used his posted files as a starting point.) I understand he got the files off of somebody else, too. Either way, I was really glad to have them available as it saved me a lot of time entering the schematics into KiCad.
My suggestion would be to also add a PDF print of your KiCad schematics to your github. This may seem useless, since they are just as static as the original Apple schematic PDFs. But it helps when someone finds your project, since the PDFs can be viewed instantly with the browser. Allows people to assess what your KiCad project really is about and what the quality is. Then, if they find it useful, they will invest the effort to clone the git project, so they can view them with KiCad...
I can see the reason, though, why the caps had to be renamed to non-standard names in the KiCad schematics: unfortunately the component identifiers in the original Apple schematics are not unique. Apple used C1..C99 for capacitors, as usual. However, for all ICs they used the grid location as the identifier. Hence, for example, C1 is either a cap - but it is also refers to the 74LS153 (in position C1). C2 is a 74LS195, etc.
KiCad lets you put as many fields as you like on the solder mask. You can have a field for the ICs called "Grid Location" for A1, B2, C3, etc. and use U1..Un in the Reference field of the ICs. The Reference field is the only one that needs to be unique. You can also hide the Reference field from the solder mask or the schematics and show some other field that doesn't need to be unique.
If I am to use JLCPCB to make this motherboard for me, I would have them wave-solder DIP sockets for the ICs, since it will take me a couple of years to find all the ICs. All the sockets having identifiers starting with different letters of the alphabet will be incredibly confusing.
My thought is that existing literature appears to refer to components by their grid location. So referring to A8, for example, as U28 would cause some serious confusion. Since I haven't seen any capacitors listed with a designation, the capacitors could be referred to my any number. I am thinking of referring to the capacitors as CP1, CP2, etc.
You can label the ICs any way you like in the schematics or the PBC layout. For example "74LS251-H14" like Apple has done above. However the Reference field in KiCad is special and it is highly integrated with the tools of many PCB manufacturers, which if why I was suggesting to use the standard nomenclature in that particular field.
What I would love (and I lack the time and ultimate Kicad skill to do it) is a Rev-7 motherboard design. Rev-7s (and RFI revisions) are way more useful than Rev-0, practically speaking and it would be a bonus if that Rev-7 (or RFI revision) could also be modified to run with 2716 EPROMS instead of having to find old (and incresingly scarce) genuine Apple 9116 PROMS.
The KiCad Rev-0 replica is really the first part of a larger project. By using the Rev-0 replica, it is possible to verify the known schematics against a known working set of gerber files. I figured this is a good idea because sometimes the schematics have errors. (Oddly enough, an error was found on the gerber files....and it has been fixed.) Fortunately, I haven't been alone in this endevour as another github member has been working on the files as well...and has a similar long-term goal.
Once the Rev-0 replica is finished, a Rev-7 would be a lot easier to do. (I am not sure if my Apple II Plus is a Rev 7, it might be.) But that isn't really my ultimate goal. My thought is that it would be nice to build a complete and somewhat useable computer using modern off-the-shelf components. The computer shouldn't have any FPGAs, and should be able to be easily modified. Since an Apple I isn't realistically that useful, I figured an Apple II would be a better target because it can be built without any special LSI chips. (i.e. Atari's POKEY) An Apple II also has a lot of software available and was upgradable enough to last into the early 1990's in one form or another.
My comment come from the fact that it's been done already and Rev-0 boards are out there in the ether - Mike Willegal's done it, there was a kid on Facebook that did it, there's a thread going on right here at Applefritter with a guy building a Rev0 replica and several chinese and russian versions of the board have surfaced...and there are boards for sale right now.
But no one has done a Rev7 / RFI board, (well that's not entirely true - Henry Courbis at ReActive Micro has done it but it's only available either complete, or as a kit) and no one has done a board compatible with 2716 chips (which would require a board modification for the inverted chip-enable pins) and put it into the public domain.
On the new design, not directly related to the Rev-0, the NE558 is replaced by 2 556 timer chips. The PROMs are replaced by a single SST39SF010. (Yes, a lot of space is wasted, but the SST39SF010 is less than $3 each.) The RAM is replaced by 48k of an AS6C1008. I think I've got the SRAM situation, and it's timing, figured out. If need be, there will easily be space on the board to make modifications as necessary. Also, all chips with low-level logic gates (i.e. AND, OR, NOT) have been replaced by PLDs. Overall, there is about a 50% chip reduction.
I have a Dell OptiPlex 745 desktop whose warranty has expired on 6th November. I am trying to learn the internals of this laptop and study its power on sequence. To do this I want the schematic. My desktop is OptiPlex 745 Small Form Factor DCCY model. The motherboard part number is 0WK833. The motherboard has PWB WF809 REV A00 laminated on it. The USB ports and other connectors have Foxconn written on them. So it looks like a Foxconn Motherboard.
If someone has a schematic for this model of the motherboard along with the board view files, can you please share it ? I have done an extensive google search to the best of my abilities but was unsuccessful in finding them.
Proprietary Dell never released schematics of their MB's. Otherwise, anybody could copy them. The closest a person can get is MB photos (whether eBay or in a manual) or the tech guide which just points to some of the parts.
I see that there are many Desktop schematics floating around. Unfortunately I was unsuccessful in finding the schematic for my model on the internet. Hence, the request, if any one else was more successful than me in finding it to share.
Pinouts for fan headers and front panel and audio and usb and and and are not published but some things can be migrated from the tiny case so that you can use a bigger case. Thermal sensor, fans, etc can be migrated. The flex bay connection is standard USB 2.0 dual output etc.
Presently, I have some unanswered questions like how the PCI bus is connected to the CPU, What is the difference between Front Side Bus and Back Side Bus, where in the motherboard is the Back Side Bus etc.
I know there is schematic on internet for Dell XPS 730X motherboard made by MSI. It uses X58 chipset. there is also schematic for Alienware 17 R2. But you would not be able to find most old Dell motherboard schematic on internet.
745 uses Intel 965 express chipset. Front side bus goes to motherboard backside is in the cpu. ok im done. You should do more research. 15 year old design is not really real world example in 2022.
The spec sheet for the 15-db0069wm is inaccurate so I would like to be able to review the schematic to answer a few Qs that I have. When I buy a mother board from a MB manufacturer I get 1 with the product but I can't seem to be able to find 1 on the HP web site.
Thanks. I had already discovered that Maintenance Guide and it answers a lot of Qs. I had posted the discovery on Tom's Hardware after the Moderator had told me that HP didn't have an M.2 in that box. He was a little full of himself but I didn't say anything. However, I think HP will void the warranty if you open the case... eben to add memory. The Guide says that a memory upgrade is not user supported but the 8 Vega cores appear to consume about 4GB of memory.
Hay folks,
I got something to share:
This is a scan of the main logic board for the DMG 01. I had been wanting an image like this for a while, and decided to make it myself. I started removing components before I had the necessary equipment, so some things aren't as pretty as they could be, but I nit-pick.
My motivation for what became a massive project started when I saw some minor inconsistencies between the only information I could find (which is right here) and what I was seeing while reverse-engineering the poor gameboy you see to the left, but it was more than enough for me to get started. I'll explain more of my motivations later. But now you get to see the fruits of my labor!
(1890 x 1854, 5.82 MB)
Before I go any further, please know this is the first revision. Everything looks right to my eyes, but they may not be as trained as some of yours. Let me know what may need to be corrected.
The biggest thing I wanted when drafting these documents was transparency. I wanted all this to be understandable to someone with only basic understanding of what circuits are and how they work. I'll give a crash course later in this topic on how to read this schematic if you're having troubles.