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View topic - Sega Keyboard (SK-1100)

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  • Joined: 05 Nov 2014
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  • Location: Auckland - NZ
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Sega Keyboard (SK-1100)
Post Posted: Fri Sep 20, 2019 12:30 am
Just for reference here are some photos of the SK-1100, which may be useful one day to some one.

More info can be found here

http://www43.tok2.com/home/cmpslv/Mark3/Sk1100.htm

Ive also attached the relevant circuit diagrams from above for reference too, just in case.

There is also a discussion below about the keyboard and detection of it.

http://www.smspower.org/forums/17648-SG1000PortDEWriteReadAtBootPattern

Interestingly the cable pins are bridged from top to bottom. Even though only one half of the pins are used on the expansion port, the contacts can be on either side of the expansion port and it will still operate.
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  • Joined: 05 Nov 2014
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  • Location: Auckland - NZ
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Post Posted: Fri Sep 20, 2019 1:25 am
Interestingly enough it looks like the rubber key membranes and the matrix contact board are probably the same as used in the SC-3000 ones. The only difference i can see is the power LED is not fitted and the reset key is removed. Im not sure if that key was a separate molding all together as it was yellow, or if it was just printed yellow at the same time as the key text.
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  • Joined: 28 Sep 1999
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Post Posted: Fri Sep 20, 2019 3:39 am
This is great stuff, I've never seen inside the keyboard before. Really looks just like the SC-3000 internals. Somehow I missed that it supported the tape interface too, that's a lot of value.

I wonder if we'll see a USB or PS/2 keyboard adapter in the future? :)
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  • Joined: 05 Nov 2014
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Post Posted: Fri Sep 20, 2019 4:26 am
Charles MacDonald wrote
I wonder if we'll see a USB or PS/2 keyboard adapter in the future? :)


I was wondering about attempting a PC keyboard for a laugh too. I guess the lazy way would be to use a micro to read a PS/2 keyboard and output that into a x / y grid that matches the sega keyboard, then feed that into the PPI chip.
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Post Posted: Tue Sep 24, 2019 12:36 pm
I started having a play with doing this from a ps/2 keyboard tonight. It might not be too difficult. I can read a keyboard in with a micro, which is half way there. Juat need to impliment a bunch of logic to drive the x/y grid and come up with a lookup table to tie it all together.

Is there merit to having support for the tape interface? I did a little bit of looking around and it seems fairly simple. Need to do a bit more reaearch with a scope to figure out exactly what goes on there tho.

The printer port probably has no real use, so might just leave that out.
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Post Posted: Sun Nov 17, 2019 8:01 am
Well.. i got a prototype going. Found some surface mount 8255 compatable chips. Theres a bit of programmable logic between that and a micro which then deals with the ps/2 keyboard. I added support for pause/restart too, making use of the nmi pin on the sms cart connector. Ive also got a d-pad mode working which turns off the console joystick ports and then emulates them with the keyboard arrows etc. Needs a bit more work yet but the concept works.

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  • Joined: 14 Aug 2000
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Sega Keyboard (SK-1100)
Post Posted: Sun Nov 17, 2019 11:50 am
This is way cool. Bloody kiwis and their ingenuity :)
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Post Posted: Mon Nov 18, 2019 10:24 am
Amazing work Wasup!
(Count me in if you end up making a small batch ;)
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Post Posted: Mon Nov 18, 2019 9:35 pm
Bock wrote
Amazing work Wasup!
(Count me in if you end up making a small batch ;)


Sure thing :)

I still need to look at the tape interface portion of this and see if i can get that working too. Its got a small custom part that sits between the ppi and the tape jacks. I need to scope that out and see what it actually does. Not sure how useful the tape interface really is just it would be nice to get going for the sake of it.
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  • Joined: 04 Jun 2020
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Post Posted: Thu Jun 04, 2020 12:50 am
Well this thread was a nice surprise during all my research. Did you ever make any more progress on this? Not to sound like an armchair hardware hacker, but this replicated keyboard controller could be put to use as an internal mod like the internal 3D glasses mod. Add jacks for the PS/2 keyboard, tape drive, and parallel port, and you've got a certifiable Master FrankenSystem.

If one of the other posts on here is any indicator then it shouldn't conflict with the FM sound board either.

Referring to one of your other posts this would enable the use of the Mark III link cable (or homemade equivalent). At the very least it sounded like you got some sort of goofy hacked keyboard setup working.

Call me crazy, but if you add all these mods to both a VDP1 and VDP2 console, then add an Everdrive, then every game should be playable one way or another, right? Might require some hacking to get some of the card games to work, same for region-lock issues, but VDP1 enables the Japanese version of Ys and the VDP2 grants access to the 224-line mode Codemasters games. The often-cited VDP guide mentions Ys and the Codemasters games are listed in several other guides elsewhere. Might need a region switch, 50/60 Hz switch, and a few other things, but add four controllers worth of electronics and you can then almost justify two consoles since you would be able to play one ancient combat flight sim in multiplayer on both :P

Any foreseeable hurdles to making this a reality? Are any of the electronics for the tape drive or parallel port hard to source without destroying a working SK-1100?

I've got links to the various posts I cited above, but I can't add them without approval.
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Post Posted: Thu Jun 04, 2020 3:12 am
I got to a point where i built 2 working units to try and get f16 working in multiplayer mode but couldnt get it going. You can chose multi player then select to be player 1 on one console and player 2 on the other console but it seemed to be waiting for something to happen at that point. If you press button 1 or 2 one of the consoles would start the game and the other seemed to freeze. I kinda ran outa time to look at it further and put it to one side for the moment.

I had plans to combine this with other things i worked on to make an awesome adapter for mk iii compatability.
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Post Posted: Sat Jun 27, 2020 5:14 pm
This is great! If you ever reach a point of wanting testers or buyers I am interested. I have the original keyboard but would love a way to get Sega BASIC running on "export" machines with a keyboard attached somehow
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Post Posted: Mon Jun 29, 2020 1:04 am
bsittler wrote
This is great! If you ever reach a point of wanting testers or buyers I am interested. I have the original keyboard but would love a way to get Sega BASIC running on "export" machines with a keyboard attached somehow


I got my sk1100 working on a master system. The master system bus is just missing the /kbsel signal which you can make with a bit of external logic. I had timing issues with disabling the internal controller ports though.. so it was a bit touch and go but the general idea worked.

It would be nice having it on a game gear with tv out and then patching the colours properly so it looks more reasonable.
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