iMac Plus First look, What do you think?

[GeekyBit]

So what is this?

Well there are a lot of Mac Plus Logic boards out their. Often times the cases and even more often the CRTs are bad or don't work. Sometimes they can be fixed but not always. People Really want the Mac Plus and Mac 512k/128k and the can't get them because they are too pricey, but the logic boards are cheap.


So here is my idea. I want to make and sell a fully 3d printed Case that slim-lines the Mac Plus form factor. The idea is this would use a LCD screen instead of the CRT. It would need need a Custom PSU solution. Then Things I would like to get in there is an internal SCSI Hard drive slot for say a BlueSCSI or even an old Hard drive.

So let me know what you all think If you like it, I will see what I can do about making it.

 

[reallyrandy]

I love it. That being said, I think some serious engineering would have to go into the PSU and the Logic board connection to the LCD. The mechanics of it (wiring, case dimensions, etc.) would be the fairly easy part.

Has anyone here wired a Plus logic board to an LCD?

 

[GeekyBit]

I love it. That being said, I think some serious engineering would have to go into the PSU and the Logic board connection to the LCD. The mechanics of it (wiring, case dimensions, etc.) would be the fairly easy part.

Has anyone here wired a Plus logic board to an LCD?

There have been a few how have gotten LCD to work @Stephen Said he is working on an LCD solutions in general ... I know the power supply will be the big thing but I know @Androda is good with those so I may pester him with that... I am helping him with a 3d print for a PSU he is working on right now.

There are a few ways to get the video out that people have tried.

One of the other things I think I will do with this is try to make it Semi universal so it can take a Mac 128k - SE/30 Board .... Since that should add too much extra work and will make this thing that much more General purpose. That would complicated the PSU issues though.

 

[RetroTheory]

Oh great idea , on the PSU side , the Meanwell RPT-60B PSU would have the +5V,12V and -12V
For video, the pi based RGB2HDMI (https://github.com/hoglet67/RGBtoHDMI) can do that
And as a Pi it can do double duty as a retro station with the swap of an SD card.

 

[RetroTheory]

Can a -5V rail be added to something like the Meanwell 60B?

You could add a 7905 regulator to the -12V rail to get -5V, however the RPT 60A version has -5V,5V and 12V if -12V was not needed

 

[RetroTheory]

I apologize but I'm a bit of a novice when it comes to electronics on this level. Does the Mac require a -12v ?

The Mac Plus requires 5V for logic things, +12V for floppy, and -12V for serial.

 

[RetroTheory]

In newer Macs yes , -5V is for serial

 

[JDW]

I voted Yes for the concept, but how would the LCD work, since you wouldn't be able to find an LCD in the native 512 × 342 pixel resolution, and going to a higher resolution would present some undesirable issues?

Also, if it has a real working floppy drive inside, it would need to be an old Sony 800K drive to retain 400K and 800K floppy disk compatibility.

And finally, taking a wild guess, what would a ballpark price be for such a kit?

 

[reallyrandy]

I'd really like to see a regular Plus with an LCD and a smaller, flatter PSU without flyback and all the stuff you need to drive a CRT as a working proof of concept. If that could be done successfully, then this project could launch with confidence.

You could always leave out the floppy and use an external in order to keep the housing as small as possible. Now, what would really be cool is if there was a built-in serial to ethernet port converter and a spot for an internal SCSI SD. Then the floppy wouldn't be nearly as important.

 

[sfiera]

I thought -5v was for the serial. Now I’m confused.

The Mac Plus does use -5V for serial, but the analog board doesn’t supply it. The analog board supplies -12V, and the logic board has a 7905 voltage regulator at Q1 that generates -5V from -12V.

 

[mg.man]

Just a thought... should this be the "iPlus"?

if it has a real working floppy drive inside, it would need to be an old Sony 800K drive to retain 400K and 800K floppy disk compatibility

Don't the "Sony" 2M (1.44Mb) drives work with 400k disks? Isn't the issue IWM vs SWIM? Don't the "2M" Sony's behave as 800k when attached to an IWM-only logic 'board? AFAIK, the only difference between 400k / 800k is single vs. double-sided. Of course... the original 400k drives "sound" so much cooler!

Something else... why not (assuming you go Sony 800k / 2M floppy) have the drive horizontal - making the base a little thicker to accommodate...

 

[mg.man]

you wouldn't be able to find an LCD in the native 512 × 342 pixel resolution

Didn't Adrian (of "basement" fame) use a RGB2HDMI and double the pixels? 512 x 2 = 1024 and 384 x 2 = 768... 1024 x 768... sounds familiar?

 

[mg.man]

Oops... 342 not 384... hmm... I still think he did something with "doubling"?

 

[sfiera]

Assuming sufficient wattage, sure. To run a Mac Plus logic board without an analog board, those are the three voltages you need to provide.