Epic! 8-bitguy uses 1 weird trick to detroy rare prototypes!

[Enig]

Me and a friend have been autisming on and off about the compact Macs and we've realized that the Classic II could probably take one of those repro SE/30 motherboards using 45 degree angle ROM/RAM slots and a wire harness to adapt it to the CII's combined analog/PSU board due to the CII being a cost reduced recycling of the previous machine, only caveat is you'd need to install a manual brighness control knob to the analog board's control line and dremel out the case's old I/O area but the two are so similar than the CII's connector and 12 of its 14 pins are just the SE/30's flipped 180 degrees with the last two pins being an audio lead to be connected off the mobo and another 12V line needed for the SE/30 side that can be tapped off the hard drive cable that's redundant after installing a SCSI to SD sled. No way in hell of fitting either color model in there though due to Applel moving over to an edge connecting harness and thinking it'd be cool to move the card slot right next to the PSU among other stupid design choices.

 

[Pee Cola]

Me and a friend have been autisming on and off about the compact Macs and we've realized that the Classic II could probably take one of those repro SE/30 motherboards

Finding a dead Classic or Classic II shouldn't be hard, as many of them have been battery bombed and are fit only for a fishtank conversion. The hard part - which may be nearly as hard as all the mods you're planning - is finding one for a reasonable price. But if you can manage that, more power to you.

 

[Kalsarikännit]

That's an interesting thought, @Enig. If you go through with it, let us know how it goes! I might want to do it too.

 

[DagothUr]

Simplicity itself. I've wanted to buy an Apple I kit for quite a while, but unfortunately then I'd either be stuck finding vintage chips, or worse, basically assembling a much more powerful SBC from components to run an Apple 1/2 emulator on,

I'd have thought any commercial kit would be designed around ICs that are still in production or at least are easily sourced.
Obviously, a modern CMOS 65c02 is not the exact same as a 70s NMOS 6502, nor is 70ns SRAM and EEPROMs, but imo it is still close enough to an actual Apple I to be worth considering. It's definitely not as bad as those """DIY""" projects where they just stuff a raspberry pi in a box running an emulator, and is still very educational about how the actual system works (its functionally identical).
Although I'm not sure exactly what they would do about the shift register memory in the video circuit. I don't think there's any modern equivalents, so maybe they will change it to use SRAM instead.
Another thing is whether or not you have a TV/monitor that can accept black-and-white NTSC composite video. (Apple ][ would also have this issue, if not worse due to colour).

There's a dude out there doing a restoration of an old PDP-12 at his college. It's actually a mildly interesting series, though it's kind of peak 'take advantage of your EECS students for youtube views'.

Here's another guy who restored a PDP-11 with a discrete CPU. He also has a series restoring PDP-8, but I don't think he finished that.

 

[Susanna]

I'd have thought any commercial kit would be designed around ICs that are still in production or at least are easily sourced.
Obviously, a modern CMOS 65c02 is not the exact same as a 70s NMOS 6502, nor is 70ns SRAM and EEPROMs, but imo it is still close enough to an actual Apple I to be worth considering. It's definitely not as bad as those """DIY""" projects where they just stuff a raspberry pi in a box running an emulator, and is still very educational about how the actual system works (its functionally identical).

No, you're absolutely right, I was specifically thinking of the Replica 1, but the substitutes it uses aren't that much more advanced than the actual Apple 1 hardware.
There's a PDP-11 kit I used to think was super interesting, until I found it was really just an ATMEGA controlling a bunch of LEDs and switches connected over USB to a Raspberry Pi. Meeh!

Another thing is whether or not you have a TV/monitor that can accept black-and-white NTSC composite video. (Apple ][ would also have this issue, if not worse due to colour).

I've actually made inquiries about a Macintosh LC with a IIe card. Assuming the thing works, it would scratch both my vintage Macintosh itch and my Apple II itch. That also has the benefit of being fairly easy to plug into a modern monitor, I'm not autistic enough to get into a bidding war over the handful of decent remaining Apple CRTs.

 

[Enig]

Currently on my third round of Classic II repairs, and I'm just going to do a PSA here: the things are old enough that replacing caps is not enough at this point. If you are like me and see it go from stable at boot to the video having a weird vertical shimmer followed by a hard lockup, your analog board's also got failing optocouplers and diodes to be replaced. When you go to fix these things, make sure to swap in a new TDA4605, CNY17G-3, two new 1N4148s at points DP3 and 4 and maybe even check if either voltage regulator's doing good because if any of these drops below voltage the thing's going to vertical bar boot even if you recapped everything.

I've actually made inquiries about a Macintosh LC with a IIe card. Assuming the thing works, it would scratch both my vintage Macintosh itch and my Apple II itch. That also has the benefit of being fairly easy to plug into a modern monitor, I'm not autistic enough to get into a bidding war over the handful of decent remaining Apple CRTs.

Atm regular Apple IIs are now easier to get modern video from than even IIgs or a lot of classic Macs due to the explosion in low cost VGA boards, the real money sink/struggle inducer in IIs is going after the fun addon shit like a universal floppy card or the mouse card w/ mouse due to ebay retards not realizing the II mouse card and Mac/Mac Plus both used the same serial mouse. I lucked out on my IIe last year since it wound up being an absolute max dice roll due to it being a platinum IIe from Socal with the mouse card, later floppy card and super serial left installed, these are the kind of computer where you gotta look real close at the seller's pics to get the best outcome.

EDIT: potential long term timebomb, TDA4605s are now a second source thing because no one makes them now.

 

[Kalsarikännit]

When you go to fix these things, make sure to swap in a new TDA4605, CNY17G-3, two new 1N4148s at points DP3 and 4 and maybe even check if either voltage regulator's doing good because if any of these drops below voltage the thing's going to vertical bar boot even if you recapped everything.

Not strictly necessary (I haven’t needed to do it), but electrolyte still being present will mess them up. I’ve found just cleaning the analog board really, really well with IPA to be good enough so far. Obviously cap replacement is a must, though.

 

[AmpleApricots]

Everything higher voltage is ultimately a race against time because stuff actually wears down. Spilled electrolyte residue might really allow for improved conductiveness on things that shouldn't though.

That said - in general, I always just went scorched earth on battery/capacitor leakage. Desolder absolutely everything in the area. (you'd be suprised how much gunk you can find under e.g. connectors, SMD ICs and other components - capillary effect) Scratch visibly chemically attacked solder mask areas off completely and generously, best with a fiberglas pen. (If solder mask is damaged, it can't do it's job anymore - protecting what's underneath) Clean the board. Check if traces are thinned out and damaged in places you just exposed and bridge if necessary or wonky looking. Reseal with solder mask laquer/tin (depending) the exposed copper. Toss and replace easy to replace parts that touched the leakage with new ones. (passives, connectors, sockets etc.) Properly clean not-easy-to-replace parts (e.g. custom ICs) throughly and re-tin them before soldering them back in. It's kind of a non-elegant and brainless approach but when you put all back together shit tends to just reliably work. Much easier and time-saving than to hunt down some wonky part just to find out the problem only exists if you put some pressure on some part of the PCB because of a minimally corroded trace that gets interrupted then. Intermittent problems are just the worst.

 

[seri0us]

When I was first learning to solder and trying to fix something I accidentally completely destroyed the solder pads instead.... It was "only" a cheap electronic but the amount of modern waste especially ewaste is nearly brings me to literal tears.

 

[Fcret]

There's a PDP-11 kit I used to think was super interesting, until I found it was really just an ATMEGA controlling a bunch of LEDs and switches connected over USB to a Raspberry Pi. Meeh!

The big problem with the PDP-11 is that it predates microprocessors - its architecture is entirely bespoke so you can't even really buy anything 'like' it. Even the cost-reduced miniaturized version used a weird set of LSI chips that haven't been made since the 80s. Ironically, it's probably easier to find a Soviet clone of a PDP-11 that you could reasonably fit in a home than the genuine article.

But tbh, I think the best way to experience the PDP-11 is with SIMH and a copy of one of the early research operating systems. Most users only ever interacted with one via a teletype anyway so it's not like an emulator on your PC is that much of a qualitative difference in terms of experience.

 

[Enig]

Classic II update: it's finally 98% working, the thing turns on, doesn't crash on itself, boots into 7.6.1 perfectly, and not only is the FPU board working but so is the 30mhz crystal I threw on it since I had a spare from a Starfox overclocking experiment from ages ago.
The problem, though? Something in the parts for vertical stabilization are wearing down and now are heat sensitive, so for the first 10 to 20 minutes of running half the screen gets a squeeze and a shimmering effect that if it were fast enough could work as a decent way of blending screen dither or faking AA on text, and the shimmering distortion even seems to be sensitive to large white boxes since moving a finder window down there pushes the visual effect downward some. It's fucking bizarre but hey, the computer works again.

Also a thought I had today, why is it that Doom for DOS got insanely autistic custom execs that let it do demented things like run on an 8088 in CGA but no one's used either the regular source or one of the Doom for Mac dev CD rips that has source to do the same thing for Macs? Imagine the deranged shit to be done there, like adding FPU support to speed raycasting up, having a fallback sound driver for older hardware that mixes music over three channels and pushes sounds down the fourth, or even a 1-bit video driver to give it support as low as the Mac Plus. Same goes for Wolf3D, there's goofy things to be done for either of those.

 

[AmpleApricots]

This might be an unpopular opinion, but I never cared much about Doom or Wolf3D, even back then. The somewhat later Duke3D was much more fun and felt more like an actual game instead of "autists like repetition: the videogame" the former two were.

Mac

I've been catching up with developments for the Amiga in the last few days and was fascinated how much love that system has been getting compared to a few years ago. There's new games released occasionally even, and you can even buy new (and improved ) cases for some of the models, even injection molded, plastic ones that are objectively better and more qualitatively than the original ones. There's tons of hardware to even connect USB keyboards and mice to them, even those Amigas that had their keyboard built in. You don't even have to trawl githubs and solder these yourself, there's proper stores with warranties and everything.

Then you look at the PC and Mac sphere and zilch. A wet fart. Even for basic things like PS/2 adapters you kinda have to dig and probably make them yourself. This is mostly interesting considering how much more capable both PC and 68k Macs were. The Amiga was relevant for a time in the late 80s. The new chipset it got in the early 90s was a joke, and there really was almost zero software or very poorly made VGA ports. This intense love is based on maybe 5 years of relevance and even as somebody who likes the Amiga and has hardware, I don't get it.

 

[Ahriman]

What is the general consensus about Naomi?

 

[Kalsarikännit]

Then you look at the PC and Mac sphere and zilch. A wet fart.

Absolutely not true for Mac, especially compared to 5+ years ago. (And the Amiga scene is definitely more active in comparison). Can’t speak for PC.

And to answer @Enig ‘s question: because there was an autist willing and capable of doing it. Most people on Mac don’t expect doom to run on the compacts, and if you want to play doom you have many options for computers that are capable of it. Programming for 68k/PPC does pique my interest, though.

 

[Pee Cola]

Absolutely not true for Mac, especially compared to 5+ years ago. (And the Amiga scene is definitely more active in comparison). Can’t speak for PC.

THIS. Where do you reckon all those SCSI emulators came from? Then there are the new PCBs being produced for compact Macs.

That being said, if @AmpleApricots is impressed with how active the new Amiga hardware and software scenes are, his head would spin if he knew how active the Acorn and ZX Spectrum scenes are for hardware and software respectively.

 

[AmpleApricots]

Absolutely not true for Mac, especially compared to 5+ years ago. (And the Amiga scene is definitely more active in comparison).

I concede on the Mac, although last time I checked (which admittedly, might be in fact five years ago) I was looking for a PS/2 to ADB adapter and couldn't find anything besides an adapter from the 90s you had to hunt down on eBay. If that changed, the better. I did recently try to find a usb mouse/keyboard adapter for AT era PCs and my search turned up nothing substantial besides aforementioned github projects. I did stumble over selfbuilt retro PC projects though, so maybe my statement wasn't entirely fair, but I think it is at least safe to say that the experience is not as "gentrified" as the Amiga one. It's mostly that I am lazy though. PS/2 style protocol adapters are a small side project with the right microcontroller nowadays.

ZX Spectrum

I saw the molded cases. It also kinda blows my mind currently that you can buy a mint, newly made C64 case for about seventy bucks. When you liked old computers in the 00s and early 10s there really was little, that's kind of the mindset I am coming from. Had to make do with whatever obsolete stuff, niche products and spares you could find. I'm less proud of my Amiga accelerator collection now since you can get much better ones nowadays. (and that really isn't surprising, these modern parts have *room* for programming and can drive timings that old hardware, RAM and programmable logic could only dream of, different world really - can really push the CPUs to their limit under optimal conditons now)

Your Speccy adverts took root and I dug out an Harlequin 128 board (Issue 2D) I got on ebay a few years ago on a whim. (It was like, eight bucks) I stumbled over all the shops and buyable hardware when I tried to find a parts list, which I didn't quite manage. I found other revisions' parts list though and together with what I could actually find about 2D I can deduce the rest from that. I actually almost have all of the parts in my parts storage (mostly from my Z180 project) just missing some sockets, connectors and logic really. I'm probably going with HCT logic instead of HC though, because that's what I mostly have and the TTL compatibility at least in some places might help with interfacing and hacking. We'll see how that turns out because that's exactly what I need, another project.

 

[Susanna]

I saw a mod where a guy installed a proper keyboard on his ZX.
Which made me think, why wasn't that a thing in the era, too? I've touched a ZX Spectrum, it was thoroughly unpleasant, and I can't imagine sitting at it typing a whole program, let alone as an office machine (or did it get CP/M for some reason other than WordStar/SuperCalc?)

 

[Gamepads]

I saw a mod where a guy installed a proper keyboard on his ZX.
Which made me think, why wasn't that a thing in the era, too? I've touched a ZX Spectrum, it was thoroughly unpleasant, and I can't imagine sitting at it typing a whole program, let alone as an office machine (or did it get CP/M for some reason other than WordStar/SuperCalc?)

Absolutely. Even back in the 80s there were aftermarket cases/keyboards for the ZX80.

 

[Enig]

Found my next install for the CII.

Replaces the default 60mm air intake with a 80mm box that gives everything inside airflow instead of just the power board, pretty sure the og fan died anyway.

 

[Kalsarikännit]

Found my next install for the CII.
View attachment 5813193
Replaces the default 60mm air intake with a 80mm box that gives everything inside airflow instead of just the power board, pretty sure the og fan died anyway.

Interesting, ususally I just do a same-size Noctua fan swap.