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Whilst trying to get up to speed on KiCad, I've watched a lot of Tutorials and this is by far the most useful video I have found online. The AutoRouter is an amazing tool and I've not seen this anywhere else. Many thanks!

That core memory module was used in a Facit 1125 made by Sharp. It was also branded as an Addo-X 9958 and Burroughs C3350. I have the Facit model that isn't working. (Core module SN: 8070015). Hopefully I can fix it.

Pretty amazing to watch it working the puzzle. I see no reason this cannot be done to perfection with the right coding.

Just bought my second 1200S. Great instruments..

What if I am doing RF tracks and need curvy tracks. No hard angles ?

This is incredible

Thank you very much de w0it

Autoroute creates ugly layouts. They will fail in EMC tests and reduces producibility. Very seldom used in professional field.

Very interesting, thank you!

I see in the shematic there are 4 nand gates that are part of a 74ls00 chip. When the schematic is imported into the pcb layout they are replaced by the pinout for the package. Can someone point out where this is explained? wher do the breakout symbols come from and how do they get related to the package symbol?

IT HAVE NO SOUL !

Great vid. For some of the “youngsters”, who started using computers after core memory was no longer the standard. Occasionally, you would get what is called a “slow bit”. The ferrite core wouldn’t flip to the opposite direction within the allotted time of the write cycle. One place I worked had this happen. Obviously replacing one ferrite core, in the field, was not possible. Sadly, I don’t remember what the manufacturers engineer did to remedy it. It seems like we were able to proceed with processing after the engineer worked his magic.

This is an excellent video, thanks so much for taking the time to make it. Now I understand how db's work! Thank you.

That MinPro looks like my XGecu Pro.

Great instruction. Very helpful. Thanks a lot.

hi mate could you be having schematic for this project

Very nice project. I have exact the same memory module since 1985 or so. After seeing Curious Marc's video's about core memory I wanted to connect my module to an arduino. Your video is very helpfull. Perhaps I can find the energy ( due to long covid not much energy )building my own version.😊

You should connect any inputs of unused gates or inverters to either VCC or GND. Floating inputs may cause the device to oscillate.

You missed a trick with the video title, mention Arduino and magnetic core memory and the hits will go up. Everyone loves Arduino and obscure applications. Great explanation and implementation.. 👍👍

The days of over clocking made easy. 😄😄

Excellent video. Thanks!

Should have filled the empty space with a NOP slide for if it ever got out of your loop.

I want a 1200S, i already have the 1200SRA and would swap my Marconi 29555 for a 1200S..!!

I'm not sure, if auto routing is ready to go. Even this is possible since some decates, the results are not impressive, due to the lack of absence of information in the netlist. I guess the result will not perforne pretty well in EMI for example.

It really is amazing,

Where is the fun in this? Just an excuse for the lazy elements to learn nothing but obtain code and pass it off as their own.

Cool!

A full project! from magnetics to pcb to coding ! Great you can store a sentence in magnetic cores!

wauw that"s something i always want to do...

Thank you.

Good job excellent content👏

Really well explained, thanks. I need to disassemble some MC6802 so looked at the 6502 as there is more info and videos on the more popular cpu. The general idea is the same.

Very well explained, THANK YOU

I have found, that with Kikad, the reason that the Ground plane does not fill all of the area's like in your video (it does it to me) is because the routing of the traces, leaves those area's without free access to GND. You will find, upon looking, that the area's are completely surrounded by traces, or even socket pad clearances. I put a ground plane on the bottom layer and it did this.

Next challenge get the rest working. Do a dump of the core!

Hi Paul, Kicad as of recently included FreeRouting as one of the Plugin options. Check it out, makes it quite a bit quicker and more seamless to use.

I didn't see how you took your pencil written schematic and made it into the digital version. I'm new to KiCad and trying to replicate a board but the learning curve to do that is very steep.

Why not use a 1MHz crystal and a couple of inverters? If present and available of course...

Takes me back a few years. Back when I was in 6th form I had an Acorn Atom (the machine before the BBC computer), and no printer. The college had an old KSR33 110 baud RS232 terminal. I knocked up a level shifter from an op amp and a couple of lab power supplies, hooked the printer vector to some code I wrote to convert parallel to serial, wrote a 6502 disassembler in BASIC and printed out a dump of the Atom ROM (4K in size IIRC). Software and hardware have improved a bit since then😊 Sorry I didn’t see your correction in the description for the previous video, they don’t show up on an iPad unless deliberately clicked.

Beautiful work .

Erm, the Raspberry Pi is built with a microprocessor, not a Microcontroller. While the Broadcom chip is considered to be a system on a chip, it doesn’t host RAM, ROM etc, and most importantly from a Microcontroller point of view it doesn’t provide deterministic execution time. The ARM Cortex A series processors are designed to run code as fast as possible (using high internal clock speeds and cache memory). The ARM Cortex M series are designed to provide deterministic performance (they always take a given number of cycles to execute a given piece of code) and have on board RAM and ROM. The Cortex R series are specialised to handle real time tasks that require immediate response.

I enjoyed the series of videos for this project I am fortunate I own a licenced copy of Orcad 17.4 professional although a steep learning currve it makes the job a lot easier looking forward to another series of videos like this one

I see U2 and U3 power pins does not have ant pin numbers but the wires are coming out this is confusing to anyone reading the schematics also the processor U1 would have probably been better upside down with pin 1 at the bottom of the pcb but keep them coming you're getting there

The 2k7 resistor is to stop the nand gate driving the DLatch signal inputs from floating if the two diodes anodes are logic 0 Also the way I approach reverse engineering is to use a database and spreadsheet. List all the components on the spreadsheet ie R1 R2 C1 IC1 etc then put the pin numbers in ue pin1 and pin2 for R1 (decide what is pin1 and pin2 for all discretes ie pin 1 is left or top and pin 2 is right or bottom diodes is obviously cathode and anode the ic are where the database comes in for example the 6502 has 40 pins you could search for 6502 in your database and then copy the result to the spreadsheet in the form of ic name 6502 in this case the pin number pin 1 pin 2 etc the pin name D1 D2 ADDR1 ADDR2 etc then what type of pin it is ie all the data pins just put DATA all the address pin would be ADDR when the spreadsheet is complete you can use the filter function to just filter all the DATA pins and this should highlight all the pins that are DATA ie the processor the eprom and ram once you see what the pins are you can quickly check with a multimeter what pins are connected between these devices once you've proved a connection exist you can give the net connecting these connections a net name such as D1 D2 etc this quickly eliminates a lot of the nets. power nets are quickly eliminated in this way obviously at the end you will be left with a few component pins that are not connected for example the 3 address lines going to the 72ls138. The way that you approached this card is fine for such a simple circuit works fine but for modern electronics where the components are surface mount and the pcb layer count is more than 2 my way would be quicker I hope this makes sense to you but overall, the video was enjoyable

Big thumbs up for getting it working!

Let me see let me see, lol

Wow great stuff Paul. PM with who you use as the fabricator

A bit behind on these, nice to see what you done. Old skool board has a look. Nowt like that anymore. If thats a inch and a half smaller I would like to see what an estimation of the man parts is :)

Nice intro to KiCad!