baldengineer / bit-preserve

Project for capturing vintage, classic, aka old computer schematics in KiCad.

Bit Preserve

Recreating classic computer schematics. Let's convert all those random scanned PDFs into a modern, editiable and re-usable format.

How it works

• Pick a system
• Find a schematic
• And start drawing!

This project uses KiCad for capturing schematics.

Notes

• If there are variants of the schematic, give them their own directory.
• If you see a system you'd like to contribute but it isn't listed, submit a pull request.
• If you start working on a system, please do a PR on the readme file in that directory and put your name there as "working on it."
• Have suggestions or questions? Then submit an issue!

More information

• Original project announcement KiCon 2019
• See additional info on this baldengineer.com post.

Rules - More like Guidelines

My goal is to have minimal rules. Right now I'd like to focus on documenting these systems somewhere. Someday, we might develop a style guide.

Bit Preserve has a few simple rules:

1. Do not upload bitmapped PDFs or images of original schematics. Instead, please link to repositories for that specific system instead.
2. Use KiCad's [Plot -> PDF] of the Schematic (not print!) when "done."
3. Add a link in the README to that PDF to make finding them easier.
4. Originally, we did not share symbol libraries between systems. (This was before KiCad changed how symbols get imported and linked in a schematic)
5. If you decide to re-create the PCB, Please do NOT upload large binaries like STEP files. Contact me if you want to include STEPs. (We'll do it as a submodule.)

Questions or Ideas

Please, submit an issue. In most cases, there is no need to email me. I want open discussions about how we move forward.

-James
@[baldengineer](https://baldengineer.com/baldengineer)

bit-preserve's Issues

Progress on schematic captures

Do you think it would be a good idea to dedicate a section of the README or perhaps the wiki for the repository
where status,progress, pictures, and videos of a capture can be documented? If in the wiki, these things will not be downloaded
when cloning the repo.

I think that being able to see the progress can motivate people to contribute to the project.

New Schematics

1. are we adding Macintosh schematics for legacy Mac products, Lisa, Mac 128k, Mac 512k, Mac +, SE, SE/30, Classic, Classic II, LC's, II's (II, IIx, IIci, IIsi, IIfx, etc), Performas, Quadras, etc? They are floating around the interwebs but no consistent repo with everything on it.

Push Access?

Sorry to be a thorn in your side :)

Would it be possible to get push access? I have a bunch of datasheets that I can push to my PC-Compatibles directory.

Apple II+ schematic lacks Jumper Blocks

CRA6, DRA6, and ERA6 are combined together. However, in reference schematics these signals are shown connected through jumper blocks.

Why no .pdf's included?

Howdy,

Submitting here because I'm sure others have the same question.

Since it github's bandwidth anyway, I'm curious what the reason is for not including .pdf's along with the KiCad design?

I can somewhat understand not wanting pdf-only submissions (although I'd personally like to see searchable pdf's included too), but by not including them even on KiCad designs, the utility of this repository is really limited to those that can successfully install KiCad. There are a whole host of reasons that might not be the case:

1. Locked down computer (schools, or some work environments)
2. Bandwidth restrictions (especially a problem in poor countries, but even some people in developed countries have BW limits or data caps)
3. Incompatibility with KiCad. There are various known issues
4. Already has a cad system installed, and either can't or don't want to install yet another (be it for security reasons, or resources, or who knows what).

I hope you'll reconsider - I think the goal here is noble and I'd like to see it have the greatest chance of success.

Thoughts on non-computer schematics?

I think this project is a fantastic idea and will prove in time to be a fantastic source of information for the community.

I have some schematics for an old Marantz amplifier that I have been looking to digitise for a few years, I saw this project and hoped you might be interested in adding it to your collection once they are done.

System Wishlist - TRS-80 Model IV

Would be very nice to have a reproduction motherboard for the Model IV as well.

Apple IIe - Wrong pinout on keyboard ROM symbol

Pin 16 is both O7 and ~CE on the symbol for UE12, 2716.

Should be:

• O7 - pin 16
• ~CE - pin 18

Apple II Schematic error

On the Apple II Schematic, IO_STB off of F3 (74LS138), should be marked as follows:

IO Strobe - goes to all Peripheral Connectors (slots)
Goes low when accessing address range C800-CFFF

Symbols for specific applications of programmable generic parts

While working on capturing the Commodore 64 schematics, I came across a situation where I am putting symbols in the schematic that are a specific application of generic FPLAs and ROMs.

Examples include the PLA (CBM part number 906114-01) that is a specifically factory fused version of the Signetics 82S100, Fairchild 93459, MOS 7700 or MOS 8700 chips. Similarly, the C64 ROMs are applications of generic 2364 and 2332 ROMs that are specifically mask programmed for application as BASIC, KERNAL and CHARSET ROMs.

In the PLA case, it's desirable to able to represent the specifics of the application in the symbol, to give meaningful pin names instead of just I0-15 and F0-8.

In the ROM case, whether chip select is active low or high is mask programmable so the generic symbol says CS/~CS - again, it's desirable to represent the specific application symbolically.

Yet, it is also desiable to retain the information about the generic parts that these specific applications are built from.

The way I propose to address these situations (and what I am currently doing in the symbol-libs contributed while working on my Commodore/C64/251469 WIP fork) is to add a symbol with the vendor specific application part number (e.g. 906114-01 for the C64 PLA) and then add aliases for the generic parts, prefixed with vendor, product and part. E.g. CBM_C64_PLA_82S100 for the Signetics FPLA application. The alias description can contain the additional information that this is an instance of such and such part in this specific application.

This way, one can still search on the generic part number in KiCad, but immediately see that it's a specific application and not a generic part that is matched. Also, the relation to the vendor part number and potential other generic applications is retained. Often there are no datasheets available for the specific application, in which case I still refer to the generic datasheets in the KiCad symbol definition.

Let me know if you see any issues with this approach or have directions for a better way to address this. Until then, I carry on like described in the above. :)

IIgs - Video Page - Double check MC1377

symbol and associated schematic may be wrong.

Make sure Pin 2 on MC1377 is connected to COMP/SYNC signal.

Atari STE link

Don't know if you'd want to clone some or all, or just put a link to it (at the risk that the repo goes away someday):
sporniket/retro-computer-clean-schematics#52 (comment)

Clarify license

Right now this repository doesn't have a license defined.

Should there be a global license for all of the schematics or would it be preferable to have a per-schematic license?

Personally I'm fine with pretty much any open source/HW license.

Atari 1088XEL, a complete redesign of the Atari 8 Bit in Mini-ITX format

https://ataribits.weebly.com/1088xel.html, respective https://github.com/ivop/1088xel-kicad

Propose tracking of sources

To @DIYsciBorg's comment on tracking from Issue 5, I can see some possibilities:

• For schematics, require a readme.md that includes the source(s) of schematics (even if "reverse engineered by me"). Sources which are online must either already be on the Internet Archive, or uploaded to the Internet Archive, and must include at least one URL pointing to the Internet Archive.

• Symbols not present in the current KiCAD release must be created and placed in a new library added to bit-preserve, or an existing library on bit-preserve.

• New symbols must conform to the KiCAD library standard. That also means including URLs for datasheets, preferably pointing to the Internet Archive. You can instead try to add the symbol to the KiCAD libraries, but it can take a while to get a component through the KiCAD pull request process. Schematics use the -cache.lib file for symbols anyway, so it's ok to use a library on bit-preserve.

SOFT5 generates Output connected to Output Error | Apple II+

A2C and A2D are NAND gates. Their inputs are tied to GND which forces their outputs HIGH. The Apple II+ schematic uses these unused gates (of A2) to pull-up the SOFT5 signal.

IIgs Schematic - Oscillator pin out is wrong

Schematic symbol doesn't match either the 256k or 1MB schematic.

Replacing footprints for obsolete parts with replacement parts.

I Finished the schematic for the Tandy TRS-80 coco2 26-302x making sure to include a footprint for each
component.

Most of the components use standard footprints so no issues there.
However, K1 is a relay that is no longer made and I can't seem to find a pin compatible relay to replace it.

A workaround would be to create footprint for an electrically compatible relay so that the schematic can remain true
to the original one provided by Tandy.

I plan on making a PCB and I think I can make one with mostly new components using modified footprints but I don't want to create something that deviates from what you might have in mind.
At least not in this branch.....

The schematic has been completed and I believe that satisfies your intended goal so my question to you is.

Do you have reservations about changing footprints even though the schematic will still reflect the original?

Atari ST (microATX)

http://ataripcb.pl/atari_st_atx_v1.1.html
For now available as Eagle Project

Apple II Schematic power-up reset transistor error

Nice job putting everything in KiCad! I was thinking about doing the Apple II schematic and found you are already doing that. That's a huge job!

I was studying your schematics and found that in the Apple II Schematic, Q5 (power-up reset transistor) is reversed.

Not a big deal as there's a lot of components, but I figured I'd let you know.

KIM-1 - Wrong resistor values

R18 to R23 pull-ups should be 1K and R41 to R46 should be 100R. They are also swapped in the original schematic and parts list. Checked against photos of multiple systems and also inferred from the schematic or the transistors would be permanently switched on ;)

Apple IIgs RCMEN = ROMEN

On the MEGA-II schematic page, Pin 37 is listed as RCMEN. After extremely careful consideration, it appears that might actually be "ROMEN" as in "ROM ENABLE."

Proposing the Inclusion of IBM and other ISA/Microchannel hardware.

Hello,

I am quite the fan of IBM hardware and have been working to document and recreate many original cards and motherboards. I would be happy to contribute these to the project.

-Rob

Apple IIgs - Fix library references

Not all IIgs symbols are in the "Apple IIgs symbols" library. Some are in "IIgs-Schematic Rescue" and there are multiple rescue folders.

TRS-80 Color Computer schematics

Hi, I'd be interested in working on schematics for the TRS-80 Color Computer 2, my favorite 80s computer. Does the Color Computer fit into this project, or is it mainly the original TRS-80 Model I/II/III?

C64 KU-14194HB schematics

Hi. You can add my schematics for the KU motherboard to the repo (or I can make a fork and pull request perhaps). I have it in my own repo. The design and look is closely based on 250407. I have made all the symbols to look as close as possible to the 250407. The schematic netlist is verified against the KU motherboard layout using DRC, so it should be very accurate.

IIgs - Video - C20 (and friends) are missing

DC Blocking caps between the video DAC and NTSC/PAL circuit are missing

Numerous issues. See description

Hello,

I took the schematic, reverted it back to Rev. 0, imported the willegal gerbers, and was able to compare the schematic with the gerbers.

Issues include:
Wrong CAS on many RAM chips.
Wrong RA6 on many RAM chips.
Latches on Video Generation schematic duplicated on RAM schematic.

I've uploaded the corrected Rev. 0 schematic at: https://github.com/reifsnyderb/Apple-II-R0