My little guide on RGBTOHDMI installed on Classic, Plus, etc.

Mu0n

Active Tinkerer
Oct 29, 2021
570
529
93
Quebec
www.youtube.com
This is the video that inspired me to follow in his track (Adrian's Digital Basement) and install a RGBtoHDMI pi zero + hat + buffer board to first my Macintosh Classic 1, then to my Mac Plus and eventually to a SE/30 in an upcoming update to this thread.


Project page to RGBtoHDMI: https://github.com/hoglet67/RGBtoHDMI

Quick link to my full Mac Classic 1 RGBtoHDMI configurations (on the device): https://tinkerdifferent.com/threads...installed-on-classic-plus-etc.2475/post-24640
Quick link to my full Mac Plus RGBtoHDMI configurations (on the device): https://tinkerdifferent.com/threads...installed-on-classic-plus-etc.2475/post-24641
Quick link to my SE/30 RGBtoHDMI configurations (on the device): https://tinkerdifferent.com/threads...installed-on-classic-plus-etc.2475/post-25236

Specific board (hat board to the pi zero) I got to make sure I didn't gamble on something that strayed too far from what Adrian did:

I got the deprecated RGB 6/8 bit board here: https://github.com/hoglet67/RGBtoHDMI/wiki/Bill-of-Materials-(6-and-8-Bit-Boards) and had it made either with PCBWay or JLCPCB, I forgot which.

I also got the PC TTL buffer extender board, very important since it has diode chips to prevent the signals from returning to your mac:

For the CPLD chip that's used by the hat board, they were available on mouser or digikey back then when I sourced my material, no idea if it's still easy to get. Good luck!


Snapshot - 84.png


When you finalize the assembly, you'll need a small HDMI to regular HDMI converter and for the actual link to the wires that come out of my compact macs, I used a DB-9 (aka DA-9) connector, the same used for CGA / EGA PC monitors. You're just using 4 pins out of it. I used the great documentation in the above github page.



1679065145924.png

(older version where I had stripped soft wire ends that weren't very solid in the DA-9 connector pins)

1694011062429.png


You can find 3d printable cases out there, here's one I found quickly and seems to be available in March 2023:



Getting a Raspberry Pi in 2023 little offshoot guide:
-=-=-=-=-=-
For sourcing a pi zero, anything that's not a pico or pico W (rp2040) is hard to get, but NOT impossible. I was able to buy one in early 2022 and then the severe raspberry pi drought occured worldwide. It *IS* possible to buy some in 2023 as they are coming back in waves that sell out quickly with stores attempting to mitigate scalper activity. Here's the method:

1) you sit down with https://rpilocator.com/ opened on weekdays, properly set up to your preferences
2) you made accounts in advance in the stores you aim to buy from (ie Adafruit, PiShop, Sparkfun, etc)
3) you ACTIVATED 2FA capability in those websites as well and are ready to stay logged in for the week day dropdowns (read below)
4) you prepared IN ADVANCE a wishlist that you can add to your cart in 1 click (if supported, that's how I got a pi zero from adafruit US)
5) around 9-10 AM EST, some stores release 100 units oftentimes during some days of the week. There's no cemented pattern, you have to check it out many times during the course of several days to get a feeling. You can follow @rpilocator on Twitter or @[email protected] on Mastodon to understand those pattern, they post about drops as soon as detected.
-=-=-=-=-=-


The RGBtoHDMI in 1-bit mode uses 4 wires (hsync, GND, vsync and signal) and here's where I soldered my wires on my Mac Classic 1, on the analog board in cramped spaces near the microphone:

1691154523067.png

(view from inside the connectors, ie where the wires connect inside the cable.)


white to pin 4 = green 1 = "signal"
gray to pin 8 = h sync
violet to pin 9 = v sync
black to pin 1 = ground)
1694010981436.png

(revised "version" where I soldered male dupont ends for added robustness)

(as shown here, those 4 wires are soldered to the pin sides of a male DB9 connector, which itself is plugged into a female DB9 connector soldered on the RGBtoHDMI buffer TTL board)


Next up is where I soldered my wires inside my Mac Classic 1 - it's awkwardly on the analog board near the speaker. In hindsight, don't do this, use the same shove-inside the connector between analog and logic on the logic side. I did it this difficult way just to exactly reproduce Adrian's video back then while I was unsure of many steps.
1679064252500.png


Here's my configuration txt file for it
sampling=0,0,0,0,0,0,0,0,0,5,0,0,0,0,0,0,7,0,0,100,255,100,255,100,255,255,255
geometry=172,22,512,342,512,342,2,2,0,1,15667200,704,5000,370,1,0,0


Here's what I did for my Mac Plus, shoving exposed Dupont wires into the J connector (logic board side) for the cable that links the analog board to the logic board. They hold real solidly by friction and from being squeezed in. I'm not afraid they'll suddenly come out and short something.

1679064425683.png


Here's a better view of the cable sockets I used for the Mac Plus:

1694661278132.png



I did a YouTube shorts on it:

and here's my configuation file for it:

sampling=4,4,4,4,4,4,4,0,1,0,1,0,0,0,0,0,0,1,0,0,100,256,100,256,100,256,0,256
geometry=168,6,512,342,512,342,2,2,0,0,15667200,704,5000,370,1,0,0
palette=Mono_(2_level)
output_colour=1
output_invert=2
scanline_level=0
font_size=0
num_buffers=1


One day, I'll do my SE/30 as well, since I use it often for making MIDI stuff, it'd be great to have this very useful insurance against failing CRTs for the long run.



Gear I use to capture video:
I used the cheap HDMI capture usb stick that gives me a plenty good 1920x1080 @ 30 fps:

ideally, I could use 60 fps but then it started to become expensive and it's not that needed.


Here's a video where I explain how to connect it to a Mac SE/30:


Example image captures (click to see in full view without resizing dithering that ruins some of the patterns)

Screenshot 2022-06-13 12-02-43.png


Screenshot 2023-04-10 09-43-31.png


endgame.png
 

Attachments

  • 1691154615569.png
    1691154615569.png
    267.8 KB · Views: 214
  • 1691154696549.png
    1691154696549.png
    549.9 KB · Views: 208
  • titlescreen.png
    titlescreen.png
    154 KB · Views: 45
Last edited:

retr01

Senior Tinkerer
Jun 6, 2022
2,469
1
778
113
Utah, USA
retr01.com
Awesome, @Mu0n! Adrian's video inspired me to have my SE/30 send TTL video to an external display. :)

For the SE and SE/30, the process is the same except for where to tap in the video via wires or adapter to get the TTL video out to the RGB2HDMI. I have this PowerR TTL video adapter for the SE/30. From that, @Stephen created a TTL video adapter for the 128k, 512k, and the Plus. 🤓

Now, if only we could extend since the mirroring is the only option. 🧐

1679076426457.png
 
Last edited:
  • Like
Reactions: Paralel

retr01

Senior Tinkerer
Jun 6, 2022
2,469
1
778
113
Utah, USA
retr01.com
  • Love
  • Like
Reactions: Paralel and rdmark

KennyPowers

Active Tinkerer
Jun 27, 2022
243
286
63
Yeah, very basic. Check this out:

I found one of those in my SE, but it's inline with the analog board wiring harness instead of mounted on a PCB with passthrough connectors:

PXL_20230318_142527299.jpg PXL_20230318_142514464.jpg PXL_20230318_142459652.jpg PXL_20230318_142421983.jpg

Also found this thing in my Classic that serves a similar purpose:

PXL_20220328_211744529.jpg

I've been wanting to build an RGB2HDMI for awhile now to try these out, but I just now got my hands on a PI Zero. So, I'll be referring to this thread soon!
 

retr01

Senior Tinkerer
Jun 6, 2022
2,469
1
778
113
Utah, USA
retr01.com
I found one of those in my SE, but it's inline with the analog board wiring harness instead of mounted on a PCB with passthrough connectors:

Yes. That is the Power R model 2703.

1679161945277.png


Connectors are necessary due to the cramped space in the compact case. You already have the connectors ready and the video adapter in place in your SE, whereas I will need to find or build the right connectors to put that in my SE/30.

Also found this thing in my Classic that serves a similar purpose

Is that the Power R model MC-10? Does it have any labels anywhere?

1679161812828.png
 

JDW

Administrator
Staff member
Founder
Sep 2, 2021
1,249
1,112
113
53
Japan
youtube.com
@Mu0n, I saw your reply under this FB post by @Ron's Computer Videos today, which brought me back to this thread. I re-watched the Adrian's Digital Basement video you linked in your opening post and noticed that during his Crystal Quest game play, the display is stretched vertically. Note how the objects which should be round are not. They are taller than they are wide. So is it really pixel perfect in his video? Or is it pixel perfect but we can just correct for that vertical stretching by changing the height on the vintage Mac's analog board?

You mentioned on FB today that you've been using your setup for over a year, so you've no doubt seen this. Thanks.
 

Mu0n

Active Tinkerer
Oct 29, 2021
570
529
93
Quebec
www.youtube.com
@Mu0n, I saw your reply under this FB post by @Ron's Computer Videos today, which brought me back to this thread. I re-watched the Adrian's Digital Basement video you linked in your opening post and noticed that during his Crystal Quest game play, the display is stretched vertically. Note how the objects which should be round are not. They are taller than they are wide. So is it really pixel perfect in his video? Or is it pixel perfect but we can just correct for that vertical stretching by changing the height on the vintage Mac's analog board?

You mentioned on FB today that you've been using your setup for over a year, so you've no doubt seen this. Thanks.

I had to go back to his video to understand what you were talking about.

Here's his video where the URL timestamp will get you to a moment where you can see Crystal Quest:

Here's a still of that moment:
1690630715849.png


Here's one of my OWN videos playing Crystal Quest as well, featured on my channel. I used my Mac Classic 1 back then, so the comparison is extremely on point. I hadn't done my Plus at that time. Currently, the one active RGBtoHDMI I have is instead installed on one of my Mac Pluses. I have a free RGBtoHDMI floating destined for my SE/30.


Again, still of it:
1690630822965.png


As you can see, I avoided the problem altogether. I remember I couldn't make my device work with his settings exactly as is, I had to fiddle around. I don't know if the changes affected what I received as a video image. It's possible it's a difference in video capture equipment as well.

if you check his fiddling of the settings of the RGBtoHDMI during his video, the geometry seems to be very similar:

Mine:
1690631436788.png


His:
1690631611068.png


Also, his settings in Crystal Quest seem to get "tall" pixels after he made the switch to Main Menu/Scaling/Interpolate 4:3/Soft


Before the switch:
1690631661463.png


After the switch:
1690631714151.png


I did not make such a switch.
 

Attachments

  • 1690631446581.png
    1690631446581.png
    379.7 KB · Views: 34
Last edited:
  • Love
Reactions: JDW

Mu0n

Active Tinkerer
Oct 29, 2021
570
529
93
Quebec
www.youtube.com
On a related note, I sent Adrian a letter with a magnet of my channel icon & forum avatar (the "1Bit") along with a letter and a couple of QR codes linking back to my channel in general and a live playthrough of Dark Castle played through my RGBtoHDMI attached to my Mac Plus.

I mention it here since my letter talk about the fact that getting a RGBtoHDMI gave me the impetus to start a channel about black and white Macs, it is such a neat way to get a 100% clean video/still captures from that machine.

He came around to talking about it and showing it off in his secondary channel where he does his super-mini-mail-calls where he opens fan letters and gifts. The fact that so many eyes are trained on his every video absolutely gave me a significant influx of new visitors and subs to my channel. I describe it as a kind of mini-slashdot effect - and for those too young to know, slashdot was a hugely popular geeky news website around 2000-2004ish and whenever they posted any link of anything for people to check out, it would often overwhelm and crash whatever server was not prepared for the hordes of geeks all going at once. It's of course not quite like that since we're talking about youtube and my modest channel, but still.

Here's a link to his video with the proper timestamp taking you there directly:


My channel was sitting at 523 subs on the morning of July 27th. Since he posted that video on July 27th, I'm looking at 574 subs today on the morning of July 29th. This is despite having only posted one new video in July only on my channel.

Here's the Adrian "effect" visually:
1690632516676.png
 
Last edited:
  • Love
Reactions: JDW

Mu0n

Active Tinkerer
Oct 29, 2021
570
529
93
Quebec
www.youtube.com
Made some minor revisions and added pictures for the wires that go into the RGBtoHDMI.
Left to do: better picture of those same wires going into the Mac Plus J connector side.
 

Mu0n

Active Tinkerer
Oct 29, 2021
570
529
93
Quebec
www.youtube.com
I'm trying to install a RGBtoHDMI to my Mac SE/30 and I get an unstable image. Anyone else deal with this exact machine?
Taking the Classic profile I have that's stable on my Classic 1 and just flipping the polarity to H+V+ does not do the trick so far.

edit -
ok I'm an idiot. wire colors are hard to get right past midnight. I inverted hsync and vsync because I thought I could match colors between the SE/30 and my stuff still not done but on right path now
 
Last edited: