Update 12-15-16: Added photos, and some editting.

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This project has gone on so many tangents, my home is "To' Up!" (Tore Up).

Rather unrelated, or, rather, tangentially-related to a tangent of a tangent to the original goal, am now faced with the (recurring) fact that I've got dozens of perfectly-suited, but used, EPROMs and no UV-eraser.

Otherwise I've a handful of old EEPROMs/FLASH chips that would work in their place, with a little bit of pinout-manipulation. But, my EPROM-programmer doesn't handle any of the EEPROMs/FLASH chips I've got.

(Wait, WTF...? I've been staring at my *other* programmer's diskettes, contemplating loading it up as another tangent-of-a-tangent-of-this-project... with the nice side-benefit that it'd be up-and-ready for whenever I might need it in the future. I bet it'd handle at least a few EEPROMs in my collection. "The Future" is now. Duh.)

Alright, well, before that completely obvious realization that took two days to come to, I'd somewhat convinced myself that it was time to finally get around to creating an AVR-based EEPROM/FLASH-programmer.... Again, one of those things that'd be handy to have around, anyways, not only as a standalone-programmer, but also as a "library" I could use for other projects needing a Mbit or so of NV-memory...

So, not a bad idea, but something that was going to take some time to wrap my brain 'round and into.

............

Other tangents and tangents-of-tangents... They're countless, really. And the utter ridonculosity of how they've come together (or not) is astounding.

...An AGP video-card that somehow interferes with an ISA SCSI card...

...A P150 underclocked to 120MHz running on a motherboard designed for CPUs better than the 450MHz AMD I'd planned to use (but apparently is dead)...

...The P150's original motherboard whose flakiness began to feel like conscientious-objection/refusal... And the moment I realized this, it finally got past the POST screen for the first time, quite literally displaying what looked like "Googly Eyes" at the top, staring back at me...

Sorry for the bad photo...

I mean, seriously... that's not even a character.

...The P90 I already had assembled from years prior (long LONG after P90s were outdated) for the sake of doing exactly what my ultimate P120/AGP/PCI/ISA system is now accomplishing... whose RTC/battery died, resetting the BIOS defaults *every* time I rebooted (including the time it reboots after I saved new settings!).

Oh man, this list hasn't even *begun*.

As far as motherboard/CPU/card combos for a tangential computer-endeavor, I must've assembled nearly a dozen before finding one that worked. And "The List" was in no way limited to merely mobo/cpu/card combos, nor even tangential-computer-endeavors.

My home is littered with the fallout, I couldn't find my phone for days, and my cat is quite frustrated.that the few remaining safe places are basically atop the bed (which isn't safe from the fallout, either) and under the TV.

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A couple interesting discoveries, in the process, was some old writing-assignments from middle-school... wow, that kid. And, apparently, a writing of my Dad's (from the era when we only had one computer and one shared "Documents" folder) with some pretty personal viewpoints regarding our relationship at the time, and earlier. (All that weirder, discovered now when I'm roughly (maybe exactly?) the age he was when he wrote it).

And... yeah... this was, believe it or not, related to this project... Wherein I needed a hard-disk for a tangent-of-a-tangent, and wasn't 'bouts to wipe the thing without backing up some old memories, first. And... the joys of trying to figure out how to safely copy files from an HFS volume (not HFS+, mind you), with the resource-forks intact...

....

Whew!

And the danged 8088 *still* doesn't boot. Friggin' thing was designed for 360K 5.25in floppy drives, and the only one I've got is 1.2MB... Holy shnizzle, this is more complicated than I'd ever imagined. Though, I've recently read that if you attach a 1.44MB 3.5in drive, and use 720KB disks, it might actually work, since they have the same number of tracks and sectors or something weird that doesn't make an ounce of sense, considering 720KB is nowhere near 360.

Oh yeah, and I *completely* forgot about the friggin' video-card!

That was the first part of the ordeal... CGA, right? No CGA-monitor... OK, it's got an RCA/Composite output. Great, right? YEAH! Nogo with an LCD. Nogo with another LCD designed explicitly for composite-input. Nogo through my VCR (yes, I still have and use a VCR) to my Tube (yes, I still have and use a Tube-TV). And by "nogo" I mean, Nothing, blank-screen.

Finally, hours into it, I connect the thing straight to my Tube TV, and there's something, but completely illegible, not at all syncing. So, learning about the PC/XT's switch-settings, and then eventually the "trimmer capacitor" which fine-tunes the whole system-clock to sync with TVs...

And a *shitton* of experimenting with that danged trimmer-cap, reading somewhere that sometimes it needs to be replaced (but not having a replacement)... adding parallel/series capacitances... *barely* a change, though noticeable-enough to know adjusting it was doing *something*. Replacing the crystal with another (maybe it got "fractured" from years of shuffling around in boxes of bare PCBs?)

Finally gave up on that and followed some traces to the CGA card's unpopulated Crystal, to note that it's indeed possible to run the card separately from the ISA-Bus's clock... But I don't know what the other unpopulated-passives are, so instead I cut the trace to the bus-clock and dead-bug a crystal-oscillator (4-pins, powered, ~5Vp-p). Exactly the same frequency as the mobo's crystal (crystals, at that point). OK, 14.31818MHz must be right... Right? Still no-go. This time *nothing*, in fact. So I get out the ol' 'scope... Friggin' no output from the oscillator. Make sure it doesn't have an enable-input, nope. Insert an inverter/buffer... Nope... Oh-shit, the friggin' wire broke-off.

Alright!

Exactly the same as before... not legible, not syncing.

Finally, I'm like "well... maybe this thing has PAL output as an option, or something..." So looking up this friggin' card... NOTHING on the interwebs. The chipset? Not even in the request-quote-sites, definitely no datasheet.

(oh, man... I completely forgot about the friggin' corrosion! What A Mess! Yeah, "fixed" that, too... best I could within my patience... back before the deadbugging... no effect).

So, just randomly switching jumpers, at this point.

BAM.

Sync. Crystal-clear (as much as CGA on Composite can be).

I'M LEAVING MY DEADBUGGING DAGNABBIT!

Maybe I should pot it somehow.

.............................

and would you believe... even after *all that* I still haven't even begun to scratch the surface of what I've already gone through in this crazy-endeavor, "The List", and *still* don't have a booting PC/XT.

Oh yeah, the mobo was configured for an FPU, but it wasn't installed, that was the first hurdle, even before CGA. WTF... why'd that switch-setting claim an FPU if there isn't one in the socket...? Musta been bumped during all those years in boxes...? Or maybe I snagged the FPU for another system after scrapping this one? No idea, but weird, and took some time to find.

Sheesh, what all am I forgetting...?

Oh, and I planned to mount the thing in an old ATX case, a bit of irony... It'll work, but I'll have to drill some holes and add some stand-offs. But after all this, I might think about making a nice wooden box for it. Maybe something more fine-tuned to my goals of long-term hacking for THIS project.

Oh hey, one thing that actually came-together quite nicely... Dug through my old keyboards box, not expecting to find an XT (vs. the *much* more-standard AT/PS2) keyboard... but there it was... with a friggin' switch on the back clearly marked "XT / AT". So, yahknow, obviously this project was meant to be!

MWAHAHAHAHAHAHAHA!!!!

And a fun little endeavor in that, too... For some reason as a kid I had the idea that keyboards stack better in boxes if they don't have the cables attached... (and, they make for other useful things, like MIDI cables, etc.). So, digging through my old box of keyboard-cables, managed to find *the one* that'd been cut from it. Open-er-up, strip, twist, tape. Weee!

...............

"The List" is much longer than this, I've just forgotten a bunch.

In the process, though, I've managed to do some rearranging of my apartment, and now I have a new workbench!