list of chip dissections

[copperjump]

Thank you for your work uncovering the circuitry in vintage silicon. I'm looking forward to the Amiga chipset dissections once those are ready. Would also be interesting to see how they compare to versions of the chipset made pre-Commodore: Agnus (4701), Daphne (4702) and Portia (4703).

[ttlworks]

copperjump, thanks for the kind words.

There are only two guys in our team: Frank and me.
Frank does the vectorisation, I'm trying to extract/simplify the schematics,
we usually are not both working on the same chip at the same time.

Doing a chip at the size of Agnus or Daphne would take Frank one year of vectorisation,
plus maybe another 6 months of work for me for extracting/drawing the schematics.

So sadly our capacity for the chip dissections is limited,
and that's why whe put priority on finishing most of the 8 Bit MOS\CSG\Commodore chips.

[shift838]

ttlworks wrote:

Shameless advertisement:

WD1772 dissection still will take some time,
but there was some progress:

1772-02_03_04_2025.zip

Would really like to see more details on the dissection of the WD1772PH-02-02 as myself and another user want to create an disk controller for a vintage computer that utilizes this IC.

Thanks..

[fachat]

shift838 wrote:

ttlworks wrote:

Shameless advertisement:

WD1772 dissection still will take some time,
but there was some progress:

1772-02_03_04_2025.zip

Would really like to see more details on the dissection of the WD1772PH-02-02 as myself and another user want to create an disk controller for a vintage computer that utilizes this IC.

Thanks..

I assume you already know a lot about the FM/MFM format used... here's what I collected, just in case https://extrapages.de/archives/20190102 ... notes.html

André

[ttlworks]

André, thanks for the link.

There is a lot of odd circuitry in the WD1772-02,
including sort of a sophisticated 1 Bit microcontroller.

My big schematic doesn't look too useful right now,
so I need to break it apart and to draw it again from scratch.
Before doing this, I'm trying to simplify the circuitry a bit further
for making the schematic a bit smaller.

It's a lot of work, and somehow it's not a healthy thing to do.

[ttlworks]

News update for October 2025:

My father had a severe stroke in July, and died after two weeks in hospital.
The paperwork caused by his death kept me busy for 3 months.

But at least now I recovered from the failed WD1772-02 dissection.

Took a look at some part of the SSI263AP / Votrax SC-02 speech synthesis chip.
Metal gate fabrication process, and I think I can read it.
We have NMOS logic with pullups, PMOS logic with pulldowns, and CMOS logic.
There is digital and analog stuff on this chip.
That's some odd/interesting stuff.

Unfortunately, I can't finish a dissection before my working contract ends.
See, for 26+ years I'm employed on temporary working contracts as a tech at a university.
From February 2026 on, I'm forced to work for 6 months at an obscure small company
which was founded by our university department long time ago.
Last time I had been working there, I didn't like it at all, it was a bit ...intense,
and I had no spare time left for my hobby projects.

Like I said:
The stumbling block for the chip dissections mostly are real life problems, most of them job related.
Hmm... we really could need a new management.

[BigDumbDinosaur]

ttlworks wrote:

My father had a severe stroke in July, and died after two weeks in hospital.

My condolences on the loss of your father.

[fachat]

My condolences for your loss!

[BigEd]

Yes, sorry to hear that Dieter.

[ttlworks]

Friends, thanks for the condolences and the compassion.
This helps.

My father was quite active util the stroke. He died at age 87.
And the work he did in the house + garden now became my work...

[orac81]

There is this thread on reverse engineering the 6561 chip die:

http://sleepingelephant.com/ipw-web/bul ... php?t=8733

He wants to do this with the early 6560!

[ttlworks]

Thanks Orac81, we are aware of this thread.

Now for an update on the current situation:
The job at that obscure small company I mentioned is delayed due to a lack of funding.
My next temporary working contract at the university will maybe last 6 months due to a lack of funding.
Working conditions around here _still_ are getting worse.

Thing is, that the jobs for Frank and me are somehow dependent on the German car industry...
Frank is on temporary jobs which last one month each.

We will try to do the 6561, but considering the situation we can not promise anything.