Good TFT for a 512K case ?

First things first - no little 512K Macs were harmed! ;-)

I inherited a 512K Mac with nothing except the CRT inside. The CRT since went to a collector as spare part and I'm left with the case. I thought about what to do with it. Feels it'd be wrong to put something trivial like a Raspberry Pi into it.

As I've got a Mac Mini G4 left I thought about planting it inside. It should fit easily. Using the unofficial OS9 install from OS9lives.com I should be able to turn this into a compact OS 9 Mac. Arguably, I'll need to put a small TFT monitor into the case and I need to see what can be done about the ports / cabling on the backside.

I'm pretty certain others have been doing this before, so I'm looking for advice. Like, any recommendation on TFTs that fit the case and have a good picture quality? (must have DVI for the Mini)
 

wottle

Active Tinkerer
Oct 30, 2021
526
274
63
47
Fort Mill, SC
It just occurs to me, if you're using a 512k logic board then @Bolkonksij may be able to use one of the compact mac video adapters I posted about recently.
It sounds like @Bolkonksij just has an empty case, so no logic / analog boards to be used. I know many people use the old iPad displays, but I actually had good luck throwing in a 10.1 1280 x 800 LCD and setting up a raspberry PI to output 1024x768. A little tweaking of the overscan settings and it displays perfectly in the cutout of the iPad.


If you have a 3d printer, you can easily print, in black filament, a nice adapter to account for the curve of the cutout: https://www.thingiverse.com/thing:3551263

After that, you can probably mount a Mac mini inside and connect it to the LCD controller. I have a nice little setup with a RPi running Sheepshaver and Basilisk II for emulating older MacOS versions.
 
  • Like
Reactions: champagneandchips

Stephen

BetterBit
Staff member
Founder
Sep 5, 2021
204
250
63
San Francisco
It sounds like @Bolkonksij just has an empty case, so no logic / analog boards to be used. I know many people use the old iPad displays, but I actually had good luck throwing in a 10.1 1280 x 800 LCD and setting up a raspberry PI to output 1024x768. A little tweaking of the overscan settings and it displays perfectly in the cutout of the iPad.


If you have a 3d printer, you can easily print, in black filament, a nice adapter to account for the curve of the cutout: https://www.thingiverse.com/thing:3551263

After that, you can probably mount a Mac mini inside and connect it to the LCD controller. I have a nice little setup with a RPi running Sheepshaver and Basilisk II for emulating older MacOS versions.
I can't speak for the quality of the Thingiverse you linked to, I have never printed it. But I can guarantee this one will fit perfect — I spent 5 years working on it off and on.
 

wottle

Active Tinkerer
Oct 30, 2021
526
274
63
47
Fort Mill, SC
I can't speak for the quality of the Thingiverse you linked to, I have never printed it. But I can guarantee this one will fit perfect — I spent 5 years working on it off and on.
I didn't see your design, but I like that it includes tabs with screw holes to secure it when installed, I had to use hot glue to hold mine. Looks like a I have a new one to print!
 

Stephen

BetterBit
Staff member
Founder
Sep 5, 2021
204
250
63
San Francisco
Nice! Out of curiosity, might that model scale to fit a Lisa bezel? Front bezel is all I have. Curvature matches the 12" RGB ZaTopper.
Strangely, I happen to have a Lisa bezel sitting next to my desk. That should be a hint for things I (slowly) have planned. Anyway, the Lisa CRT opening is 239.5mm as a straight line from edge to edge on the width and 169.5mm on the height. Measuring the smallest points.

Lisa CRT Opening:
239.5 x 169.5 mm

Compact CRT Opening:
190.0 x 143.25 mm

Sooo I guess the scaling could look like this:

Screenshot 2024-09-22 at 12.17.56 PM.png


But I haven't tested the print so I don't know if the curvature of the Lisa CRT is 1:1 with the compact mac curvature. I am not confident that it will work that simply.

That being said, it's on my "immediate to do" to get this curvature very precisely.
 
  • Like
Reactions: JDW

Trash80toG4

Active Tinkerer
Apr 1, 2022
910
260
63
Bermuda Triangle, NC USA
Cool! Very interested in seeing that happen. The CRT curvature of the Apple Macintosh 12" RGB Display for the LC is 9all but?) a dead-on match for the Lisa Bezel. I think it's likely the elephant eared, improved CC that is the 5xx series will turn out to be a match as well.

My theory would be that the geometry of classic CRTs was pretty much a constant across all tubes, at least those of any given size in any given era? Lisa/12" RGB case in point, many years passed with near or perfectly matching curvatures.

Calculations for the compound curves of CRT tubes has to be considerably more complex then aspherical lens design. Scaling proven geometries of CRT/gun seems the path of least resistance. Why mess with the calculations for gun/rear surface? Vertically flat, horizontally curved geometry would be the next development phase?

Out of curiosity, can the thickness for sandwiching a thin vacuum formed bubble be shaved from the face of your model?

__________________________________________________________________________

Back on topic:

Controller board just arrived from Ali-Express and i purchased a Bezel Adapter years ago. Time to look for LCDs for 9' and 12" bezel matching. :)
 

Stephen

BetterBit
Staff member
Founder
Sep 5, 2021
204
250
63
San Francisco
Out of curiosity, can the thickness for sandwiching a thin vacuum formed bubble be shaved from the face of your model?
The curvature conforms, whether there's a thin sheet of acrylic or not :) I've placed a 0.75mm sheet in mine and it will hold the curvature because it's so thin and flexible — albeit, not entirely convincing due to the refraction index of the acrylic.
 

phunguss

Tinkerer
Dec 24, 2023
233
221
43
Stillwater, MN
When I converted a couple Macintosh Classics, I had an additional damaged tube (tip broken off) and I used that as a form to melt my plexi/acrylic. Put the tube in a vase, stuck it in the oven, let the flat plastic get soft.
cii_020_tube.jpg

Took a couple tries to get it right... (G5 airflow plate reclaimed).
cii_022_tubefails.jpg

But in the end they came out nice and round. Hard to see in the pics.
twoclassic.jpg
 
  • Like
Reactions: JDW and Stephen

Trash80toG4

Active Tinkerer
Apr 1, 2022
910
260
63
Bermuda Triangle, NC USA
Love it! I've got a vacuum forming rig set up on a wooden frame dropped into a 5 gallon bucket. Plexi was too thick, but managed one really good one, but not perfect enough for me. Oven heating induced bubbles in the Plex was the problem. To-do on that project is a more conventional heating element setup with drop down Plexi frame.

Had great fun pushing the worst failure to the max! Meet the Chernobyl Classic. A Twin Slot TAKKY inverted into ZFP HDD sub-basement. :ROFLMAO:

Chenoble_Classic-Twin_Slot_TAKKY.jpg
 
  • Wow
Reactions: Stephen

Trash80toG4

Active Tinkerer
Apr 1, 2022
910
260
63
Bermuda Triangle, NC USA
LOL! Glad you like it. It's the one machine in original case I have that's got room for the A/B/C Riser if I switch the 6500 board out for 6400. That started back in 2010. All pics went the way of the great pixel robbery, but for the few I'd documented of its previous incarnation with 10" Color VGA Monitor, mostly inside. Case extended with rear of monitor's case. It was my very first BenchMac, if only progressed to the Monitor stage for shiggles and gits.

MacintoshClassicIIIColorTVp™ Hack

It was intended to be a rotating three way Projector setup: CRT face, vertical gameplay on ceiling and rear projection for movies/enlarging artwork.

One day . . .
 

JDW

Administrator
Staff member
Founder
Sep 2, 2021
1,577
1,373
113
53
Japan
youtube.com
So it would seem almost all problems have been solved but the biggest one — reflections. The stock CRT is anti-reflective. I've seen photos of people who cut the front off a dead CRT and mount an LCD behind that, which is really neat, but that skill goes beyond what most people would likely be capable of doing.
 
  • Like
Reactions: phunguss

-SE40-

Tinkerer
Apr 30, 2022
420
166
43
The Netherlands
pin.it
I've seen photos of people who cut the front off a dead CRT and mount an LCD behind that, which is really neat
Quite some options….
ive found the crt conversion indeed the nicest…
.but restricted to an 8” display.
To chop the CRT, Ive initial used a conventional glasscutter, but found lateron this diamond flex cutterdisc to be the best way to get to the goal.
Its amazing, and not so hard to use as you may think. Just hold yourself to the safety measures. Experiment on some bottles before cutting the CRT.
(but you still need a defect CRT)

IMG_6704.jpeg
 

Attachments

  • IMG_2537.jpeg
    IMG_2537.jpeg
    970.3 KB · Views: 27
  • Like
Reactions: naruse and JDW