Apple IIc Schematic in KiCad 7 - Part 3

The Bit Preserve project is a Gihub Repo with vintage 8-bit computer schematics redrawn in KiCad. It's a great way to learn how to use KiCad and to help convert difficult-to-read PDFs into a usable format.

Currently, Bald Engineer is redrawing the Apple IIc's multipage schematic.

[prometheus]

Awesome, a classic machine. I learnt assembly on it

[lostmyhare]

Since you mentioned the 78xx and 79xx rectifiers around 2:25:00 I wonder if you know the answer to this... power supplies found in some of the macs have a C78N05 used for regulating -5V output from the supply. But this part isn't well known today. Two supplies I've seen these in are the TDK 699-0153 (looks like Apple PN) and the Astec AA16251 (both are also very similar to the GS supply except -12V is not an output so GS supply can be used in their place). Trying to find a replacement for the regulator but am not sure what would be correct. Is 78N05 a negative input/output like you said is true of the 79series? I believe I probed a working supply (been a while so maybe not) IIRC I found -6V on pin2 and -5 on pin3 and p1 tied to ground. -6.3V seems a tad low for -5 out but whatever. This would also not follow the 78xx/79xx naming convention. Any idea what the N in the middle 78N05 indiecates? I know the trick to have positive regulator output negative voltage by moving ground, but the boards don't appear wired in that way.

[TheDrunkenMug]

Came for the circuitry, stayed for the Windows screenres-window- placement-issues rant 😁

[johnsonlam]

Which I want to do but not able ... to have a new schematic and new alternate component list for //c and //e since the old one is blur and some components already not in production. 👍👍

[rickhunt]

I would interact but im going to take some time out to dance to the music for a while. While im dancing I'll be thinking of 74LS373 Octal flip flips with tristate outputs.

[portblock]

I would take issue with the videos downloaded for students as well. you mentioned teachers made paper copies of items and distributed to students. Yes this is true, but did teachers copy entire books and distribute? No, they didnt! If a teacher took a clip from your video and integrated into their work and told students to go watch video, that sounds good. But to copy your work and profit from it, not cool, unethical, and against copyright law