#retro-apple — Public Fediverse posts

Pulled out a bunch of caps from the Classic analog board and for the first time I can confirm it really smells like rotten fish. Yuck. And my fingers are covered in it. #RetroApple

(Well, technically I could save the scroll operation in the off G world scenario by copying the right part of the frame to the new coordinates. But the worst part is really integrating all that in the PowerPlant architecture. Maybe in a few days.) #retroApple #retroCoding

There’s a nasty trick there, in the pre-appearance manager version, I don’t actually scroll the two horizontal lines that separate header from content. Otherwise there would be a short moment where the scrolled edge would not have the lines and it would look ugly.

The lines remaining stable (like in Finder) tricks the brain, giving the illusion it’s a much more atomic operation than what it actually is.

#retroApple #retroCoding

I am extremely happy with the performance of my table view! This is an LC 475, original non-overclocked CPU (60LC040 @ 25Mhz)!

Unfortunately I still could not manage a complete offscreen scrolling, because I would have to create an offscreen GWorld, copy the window bits to it, do the scroll, then draw the empty part, and copy back, all that while dealing with the PowerPlant architecture.

But even Finder tables scroll and redraw in separate operations, so…

#retroApple #retroCoding

Same exact PowerPlant class, running on Mac OS 9.2.1 and System 7.1 😁 #retroApple #retroCoding

This is how it looks if I read the smoothed analog channel connected to the Mac Classic’s PWM output continuously. No idea why yet. In the previous video I was reading every 30ms. It looks better but if you look closely you can still see the occasional black line or artifact going by. #retroApple

For the most curious: yes, it's a gamma trick, not true DDC/CI control. I don’t know if the controller of the TFT displays being sold to put inside compact Macs handles it (I have one and will try but my desk is pretty full right now). Even if it does, I need to implement it since DispHSTX library I'm using does not support it.

I may have to write the whole DVI thing manually to support v-sync sync though, so… we'll see. But first things first, need to solve the analog read issue. #retroApple

So, huh, one more thing! ☀️

It still needs some work because reading an analog channel on the Pico interferes with sampling for some reason, like if the PIO has to pause while the analog value is read, and causes black lines and random garbage to appear on the screen.

(Apologies for the bad quality, it's surprisingly hard to film this properly, even with Final Cut Camera)

#retroApple

Also, I think it doesn’t matter but just in case it does… I tried the drive on the LC 475. Not the classic itself. I think the drives are interchangeable but… are they? I also tried two cables just in case. No dice. #retroApple

The only reference I saw to this in the 68kmla forum had people suggesting it could be the zero track sensor misaligned. But I don’t see why what would cause this issue. If it was misaligned the disk would format and write fine on this drive but others wouldn’t be able to read it and vice versa, right? Why would it pass a read test perfectly but not be able to format at all? #retroApple

I also replaced all electrolytic caps except two on the front since I don’t have small enough ones to fit there. Not sure if that may be causing this issue but I doubt it. Most other drivers I worked on were not recapped at all and work fine. #retroApple

Has anyone restored a Sony HD FDD that reads but won’t write?

I spent the afternoon restoring the Classic drive. Unlike all others I worked on before it had the top head stuck. I was able to bend the thing up so it somehow comes down successfully. Not sure if I misaligned something, I had to remove the head assembly out of the chassis but didn’t touch the screws in the head assembly itself.

Now it passes TTP read tests correctly but is not able to format or write to good disks. #retroApple

And it's merged! MacDVI, the adapter I built to wire a compact Mac logic board to a modern DVI/HDMI display, now supports the Mac Classic out of the box (with just an extra wire)!

With previous support for the 128K/512K/Plus and a report it works without any modifications on the SE, assuming it works on the SE/30 and Classic II as well (untested, but likely) this likely covers all B&W compact Macs that ever existed! 😁 #retroApple

https://codeberg.org/arroz/MacDVI

While I clean up the code, someone is trashing Tokyo. 😬 #retroApple

Looking at profiles of RGBtoHDMI, I see the pixel delay is slightly different between the Plus and Classic. I don't know their code well enough to understand what's happening, but it matches what I see. I try to sample in the “middle" of the time interval a pixel signal is stable, and that instant happens slightly earlier (or later) on the Classic. #retroApple

Got it! 😁 Looks like on the classic the h-sync signal happens on a slightly different phase compared to the Plus. Like in the middle of a pixel or so. I don’t have equipment good enough to make sure but disabling a phase tuning thing I had for the Mac plus, it works perfectly! #retroApple

Added a few buttons to MacDVI help development. However I don't seem to be able to sample the Classic output properly. Weird. #retroApple

This was surprisingly more complicated than I expected… still working for headers only, and the spacing I'm using is slightly different than the real thing (Apple uses some sort of multiplier to calculate the header height, I'm just adding a fixed size to the line height, but I can improve that).

I also don't know why the Apple Event arrives only after the refresh. Hope I don't need to check the views font on every refresh…

But… appearance manager compliance! 😁 #retroApple #retroCoding

Ok, let's try one video compressed in a different way (thank you @haitchfive!). First boot! By default the sound is quite low, unlike the Plus, but if you push the volume up you can hear the beep! #RetroApple

If you ever wondered how does Spectre looks like when running in 1-bit video. #RetroApple

I would love to show a video of this working but Mastodon still can’t handle posting videos without failing for no reason, so here’s a picture instead! Well, several! The image is a bit messed up since I need to adjust MacDVI timings for the classic, but the Mac works perfectly. #RetroApple

Punk board, or the crappiest test cable you ever saw. Getting ready for the test bench! #RetroApple

Board recapped, including a ridiculous 1uF temporary cap for testing since I don’t have any SMD with that capacity around. #RetroApple

Back home, time to do some #RetroApple! Pulled out the caps from the Classic board. Lots of nasty under them. Good thing I didn’t try to power this board before recapping.

I use the twisting method to remove them, while applying pressure down against the board to avoid pulling the traces up. Fourth board so far without any pulled trace. Guess it works?

An interesting problem is going to be adding the header view as a sort of accessory view of a LScrollView subclass, so it scrolls horizontally to match the table, but not vertically. Still have to decide if I actually do that, or keep it outside the scroll view and synchronize the frame somehow. #retroApple

My custom table view (aka DataBrowser implementation) is starting to look real, using an API somewhat inspired in AppKit, with a data source and everything. 😁 Appearance Manager only for now, and all very smoke-and-mirrors-y, but one problem at a time! #retroApple

I actually have enough 47uF Vishay tantalum caps to recap it but don’t have the 1uF outlier so will use a crappy through hole temporarily soldered on the SMD pads for testing unless I can find a 1uF in the local electronics store. They have one but it’s rated 35V while this is 50V. It would probably be fine since this is just wiring the sound chip to ground. There’s no way this board can have such a high voltage (worst case 24V from 12V to -12V). They probably used whatever they had #RetroApple

It’s interesting this is essentially a Mac Plus with ADB and PWM software based screen brightness control, yet the board is half the size of a Plus (well, plus the RAM card which is cheating a bit). But they were clearly learning to miniaturize and make it much cheaper. And thankfully they used SMDs because dealing with through holes on this boards is much harder than it looks.

I have no idea about the condition of this machine. I know magic smoke came out of the HDD but that’s it.
#RetroApple

I was trusted a Mac Classic to restore! I couldn’t test the logic board today since I’m an idiot, thought I had the right terminals to build a connector so I told the person who actually went to the electronics store before driving here to buy just the plastic connector. I didn’t.

But anyways please enjoy some photos of the board, the memory expansion card and the sacred bath in distilled water.

#RetroApple

Was there any API to build tables like the Finder ones on MacOS 8 & 9? Or was that all private inside Finder? #RetroApple #retroAppleDev