Anyone have a MacCharlie keyboard unit?

Tashtari

Tashtari

Tinkerer
Oct 13, 2022
52
74
18
This is probably a long shot considering how rare MacCharlies are, but... I find myself curious about the keyboard unit that came with them. If it plugged into the Mac's keyboard port (the one with the 4P4C phone handset-type jack), it's one of a very small number of devices that did, and maybe the only third-party one? It'd be great to document for posterity and cloning purposes what its model number response and key codes are. Anyone out there happen to have one?
 
eric

eric

Administrator
Staff member
Sep 2, 2021
1,101
1,821
113
MN
bluescsi.com
DosFox was just showing off his MacCharlie on Discord - pinged him a link to this thread.

Edit: he does not.
 
Last edited:
Trash80toG4

Trash80toG4

Active Tinkerer
Apr 1, 2022
1,109
320
83
Bermuda Triangle, NC USA
Tashtari said:
I find myself curious about the keyboard unit that came with them. If it plugged into the Mac's keyboard port (the one with the 4P4C phone handset-type jack), it's one of a very small number of devices that did, and maybe the only third-party one?
Click to expand...
Not the only one, but could be one of only two? I've got both the platinum ADB and beigy phone plug versions of the datadesk MAC-101.


Really curious to see an in depth look at the MacCharlie board. It was a surround for Apple's KBD.


MacCharlie_keyboard_complete.jpg


Steve Jobs' accursed mouse use enforcement KBD abomination . . . no cursor keys! At least the MacCharlie provided NumLocked PageNav capability.
 
Tashtari

Tashtari

Tinkerer
Oct 13, 2022
52
74
18
Cool, looks like it did plug into the keyboard port... most likely the keypad functioned like the separate M0120 keypad for the 512k/128k since it has that keypad's symbols printed on it in red, but the function keys are a mystery.
 
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
I recently acquired a MacCharlie with the keyboard extension, and I've been talking to @Tashtari about figuring out how it works. However, I've identified TEN bad key switches on it (no continuity across the pins when pressing the key). I know I can just manually short a key when eventually analyzing the protocol, but I'd really like to get this fully working. The keyboard extension appears to use the same long-stem ALPS switches as the M0110 and M0110A keyboards:

PXL_20250922_165442369.jpg PXL_20250922_165508434.jpg

Realistically, I probably need 11 or 12 of these switches in case any others decide to go. Unfortunately, they're currently going for around $20 EACH on ebay. That means it would be cheaper for me to just buy and gut an entire M0110 keyboard, but I don't want to destroy a keyboard if I can avoid it. I guess I'm wondering if anyone has some of these switches or a beater/keycap-missing M0110/M0110A laying around they'd sell me cheap A nice person on discord found me some sanely-priced key switches, so nevermind :) Also, I just powered on the MacCharlie itself for the first time connected to my 128K, and it POSTed fine and tried to hit the floppy drive, so now I just need to make a DOS boot disk for it and see if the drives are functional...

PXL_20250922_192425387.jpg
 
Last edited:
  • Like
  • Love
Reactions: JDW and bakkus
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
snuci said:
Congrats and good luck. If you need an image of the MS-DOS disk that came with the MacCharlie, let me know.

EDIT: I posted archives of the diskettes I have here: https://vintagecomputer.ca/files/Apple/Macintosh/Dayna_MacCharlie/
Click to expand...
Thanks! I'd already found the software here and got it booting into DOS 3.10, but it looks like you have a couple things that site doesn't have (y)

1759262446905.png 1759262466323.png

I've been working on replacing the bad key switches in the keyboard extension, and the TLDR is that I was eventually successful. The PCB is extremely cheap and the pads/traces lift if you breath on them. I did lift a few removing the bad switches (something I almost never do) and had to bodge around them. Then it would work very intermittently, which ultimately turned out to be because of a combination of problems. First, the cord from the extension to the M0110 connects to the PCB with a removable connector that I never could get to reliably make good contact on all 4 pins. So, I just soldered the 4 wires directly to the PCB. It was still working seemingly randomly after that, and I finally noticed that the P8748H microcontroller in the keyboard extension was only getting ~4.2v when the datasheet says it needs at least 4.5v.

1759262817471.png

The microcontroller running on fumes would explain it working intermittently. I checked the 5v at the Mac's floppy port and was only getting 4.76v with no peripherals connected. I tweaked the pot on the analog board up to 5.1v, and now the extension and attached keyboard seem to work reliably. So, if anyone else has the keyboard extension and it isn't working (but a standalone M0110 or M0110A works), check your 5v first! Now to reassemble the extension and put this whole thing together :)
 
  • Like
Reactions: snuci
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
snuci said:
Very nice to see another one running. Do you have the bottom tray that the MacCharlie and Mac sit on? Looks a little low or the keyboard is propped up.

Congrats!
Click to expand...
I don't have the bottom tray, but I 3D printed some risers for under the Mac's feet to raise it to the same height it would be at if sitting on the tray. That's why the Mac and MacCharlie line up vertically in my picture. When you have the tray, I believe the MacCharlie unit itself is still sitting directly on the desk on its rubber feet. At least that's the impression I got from this video. I did leave my contact info with the seller in case they come across the tray at some point, but I'm not optimistic.
 
S

snuci

New Tinkerer
Mar 10, 2023
17
13
3
vintagecomputer.ca
You're right. The "teeth" on the right of the tray fit tightly into the bottom of the MacCharlie so it almost becomes one piece. The Mac then sits on top of it. If you want dimensions, I could measure it. I also have a second MacCharlie that is missing the tray but it also is not working. Tried a couple of times to fix it. It's very difficult when you essentially need a Macintosh to act as a terminal to talk to it. If the MacCharlie doesn't talk, it's hard to see where the issue is. BTW, that's my video. It's far too long but I tried to be thorough so I could remember some of this stuff :).
 
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
snuci said:
You're right. The "teeth" on the right of the tray fit tightly into the bottom of the MacCharlie so it almost becomes one piece. The Mac then sits on top of it. If you want dimensions, I could measure it. I also have a second MacCharlie that is missing the tray but it also is not working. Tried a couple of times to fix it. It's very difficult when you essentially need a Macintosh to act as a terminal to talk to it. If the MacCharlie doesn't talk, it's hard to see where the issue is. BTW, that's my video. It's far too long but I tried to be thorough so I could remember some of this stuff :).
Click to expand...
Thank you! That video was very helpful! I just wanted the Mac and MacCharlie to line up properly, and I think I worked out that the Mac needed to be raised 16mm to make that happen. So, I just printed four quick-and-dirty risers for the Mac's feet to sit on:

riser.png

My printer isn't big enough to print an entire tray, but if you're able to create a reproduction STL of the actual tray, that would be awesome! I doubt the "teeth" would be strong enough to allow picking up both systems together, but an accurate model of the tray would still be cool to have :)

To "un-hijack" this thread, I've been talking to @Tashtari, and they're going to send me some equipment to help reverse-engineer the keyboard extension protocol.
 
S

snuci

New Tinkerer
Mar 10, 2023
17
13
3
vintagecomputer.ca
If I can help, let me know. I did have one of the keyboard extensions open but unfortunately, I don't have any pictures. If there was firmware in it, I didn't save it either. I do have the other ROMs inside the MacCharlie but not the keyboard firmware, if there was a ROM in it.
 
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
snuci said:
If I can help, let me know. I did have one of the keyboard extensions open but unfortunately, I don't have any pictures. If there was firmware in it, I didn't save it either. I do have the other ROMs inside the MacCharlie but not the keyboard firmware, if there was a ROM in it.
Click to expand...
The keyboard extension doesn't have a ROM in it, but it does have a P8748H microcontroller in it as pictured in this post above. I don't know if there's a way to dump the microcontroller's programming:

PXL_20250920_183539877.jpg

Here's a picture of my MacCharlie's mainboard. As you can see, I have V3 of the Charlie ROM and V2 of the Emily ROM:

PXL_20250916_200710545.jpg

The Emily ROM seems older than the V4 dump you have on your site.
 
S

snuci

New Tinkerer
Mar 10, 2023
17
13
3
vintagecomputer.ca
I have not tried to mess with 8748s but it does have 1K of programable ROM and I do have a programmer that will do 8748s. I could see if I have another 8748 for testing and see how/if it works. I'd hate to try it on a MacCharlie 8748 without testing it first.
 
K

KennyPowers

Active Tinkerer
Jun 27, 2022
317
354
63
snuci said:
I have not tried to mess with 8748s but it does have 1K of programable ROM and I do have a programmer that will do 8748s. I could see if I have another 8748 for testing and see how/if it works. I'd hate to try it on a MacCharlie 8748 without testing it first.
Click to expand...
Ya, I'm not going to let this one be the guinea pig 😳 Do you remember the part #'s of the ROMs on the mainboard?
 
You must log in or register to reply here.
Top Bottom