Hello everyone,
I would like to use my old IIe-compatible motherboard, which I used to run with an external II+ keyboard, in an IIe case.
The original IIe has a 24-pin keyboard ROM, but this motherboard has a 28-pin socket. What kind of EPROM is used there? I assume the content should be Keyboard-German-341-0151-A-2716.bin.I would be grateful for any information.
Best regards,
Wolfgang
Most likely 2764. Do you have the make/model of the motherboard? You might be able to find it on the reverse side.
IIe_comp_back.jpeg
If you are putting a 2716 ROM image into a 2764 ROM chip, make sure to create a new ROM image where the original repeats 4 times. Don't just leave the rest blank.
If it's still not working, try filling the 2764 with completely random data. This will allow you to test that everything is working and that the 2764 is indeed the right chip to use. The keys will not correspond to the correct characters, but pressing the same key should always produce the same character on the screen.
That's how I did it, if I remember correctly. I expressed myself unclearly, sorry.
That's a good tip. I'll give it a try. However, I don't think I'll have time this year, but I'll let you know as soon as I've tested it.
Thank you very much for your help and Merry Christmas.
Wolfgang
In case the random data produces results, there is a test ROM image and a program by S.Elliott you can try that should help you figure out the mapping and make your own custom ROM with the correct mapping. I did this 3 years ago when I wanted to use the keyboard encoder from my Apple II+ in my Apple IIe.
You can find it in this post: https://www.applefritter.com/comment/99793#comment-99793
The Mainboard has a keyboard controller installed. It does not need a keyboard rom since it is integrated inside the keyboard contrller. You simply connect the IIe style Keyboard to the connector besides the keyboard controller. These clone-mainboards are a one-fits-all solution and were designed to be retrofitted into a II+, IIe or clone-case.
-Jonas
It is quite possible that this motherboard doesn’t need a keyboard ROM if connected to an Apple II+ keyboard, which already has a keyboard controller (the AY5-3600-931) with the Apple II+ specific mapping inside the chip itself. However, when used with an Apple IIe keyboard it definitely needs a ROM chip, since the AY-5-3600-PRO's internal mapping is generic and the keyboard ROM is required to remap it to the keyboard of the Apple IIe.
I used to run the motherboard in an external IBM-style case with an external Apple II+ keyboard. I implemented the Apple keys via the joystick.
But the old case has been disposed of and I want to run the board in an IIe case with a corresponding keyboard.
I'm guessing jumpers X5-8 are used to select EPROM size. Might work. with 2716 installed into lower portion of socket.
More likely that it can't use a keyboard ROM if connected to an Apple II+ keyboard. The reverse side of the motherboard suggests that the LS374 is fed from both the keyboard ROM and the LS373 transparent latch from the Apple II+ keyboard socket.
It looks like the circuit can have an LS373 installed or a keyboard ROM installed, but probably not both at the same time. If it was my system, I would use a continuity meter to test if the outputs from the LS373 are interconnected with the outputs of the ROM socket. If any of pins 2, 5, 6, 9, 12, 15, 16, 19 at the LS373 are interconnected with any of the pins 11, 12, 13, 15, 16, 17, 18, 19 at the ROM socket, then both sockets cannot be populated at the same time. (ie: the LS373 must be removed if a keyboard rom is installed)
You are right. I have an identical mainboard that has (on closer inspection) seemingly another keyboard controller in the "3600-pro" socket and no keyboard rom. It works without problems and even has makros (on the keycaps of a IIe style keyboard) that work as well. My keyboard controller has the markings removed with sandpaper. I was a bit thrown off because my IIe clone keyboard works without a rom.
I may have another of these clones-mainboards somewhere. I once bought a batch of these boards from italy. Some had defective STK MMU or IOU clone chips and i got 2 or 3 running after swapping parts around. The defective STK-chips were sent to someone who wanted to decapsulate them. I have not heard back from them, though.
Please excuse the long break; unfortunately, I have only just been able to look at the motherboard.
You are correct, some of the pins listed for the LS373 were connected to pins on the ROM socket.
I removed the LS373 and, as suggested by jeffmazur, inserted a 2716 into the socket. I was unable to make any entries with the connected IIe keyboard. Only the Apple keys, Control and Reset keys worked, which ran a self-test.
I then burned the keyboard ROM twice in a row into a 2732, but that didn't work either. I had deleted the 2764 in the meantime, so now I can't reprogram it. I've ordered a new one.
When I plug a PS/2 adapter into the keyboard connector with an empty keyboard ROM socket, I can type without any problems when the LS373 is inserted. However, since I want to install the motherboard in an IIe case, this is not an option.
Thank you very much for your help and patience. I am now waiting for a new 2764.
Wolfgang
Hello,
I have the exact same motherboard in front of me.
It was working very well when for some reason it stopped booting.
I have now a random image on the screen with several beeps after a while, which means that the board does no longer detect the standard keyboard connected via the 16 pin dual in line socket.
Still trying that fix that issue that came up suddenly.
Just in case, here is a very synthetic description of the board made by JK and found on the asimov repository.
I have extracted the data related to that board.
https://www.applefritter.com/files/2026/04/28/APPLE-IIe_CLONE_JK_MOTHERBOARD.pdf
Yves
OK, I have found the issue.
Not sure why that problem appeared years after having used that computer without that mod.
The problem when you use a standard Apple II Plus keyboard with that motherboard (65C02 processor and Apple //e enhanced ROM) is that you need to pull down the Open Apple and Closed Apple signals from J17 keyboard connector to the 74LS251 multiplexer pin 3 and 4.
Otherwise there is no keyboard detection and the Apple IIe falls into a diagnostic mode.
The resistors pointed with a red square on the keboard matrix schematic needs to be added.
MOD_MB_AAIIE_JKCLONE_FOR STD-KBD_DETECTION.jpg
I did that mod on the JK clone motherboard and immediately my Apple IIe Enhanced was up and running again with the standard keyboard connected to the 16 pin connector.
MOD_FOR_KEYBOARD.JPG
Hope it helps.
Yves
The Open Apple and Closed Apple keys have the same functionality as Button 1 and Button 2 of the joystick. Maybe before you always had a joystick plugged-in?
I just stumbled upon this thread and am very late to the party, however that motherboard looks exactly the same as the motherboard in my Redstone Apple //e clone that I restored about 8 years ago:
https://youtu.be/m_-eu9YHbsk?si=jhziaec1ZkcPE-5X
I don't know if the motherboard was made by Redstone or if they simply used an off-the-shelf Taiwanese clone board. If I was to take a bet, from what I've read online (and there isn't a lot!) I think Redstone may have manufactured these boards and put them into various cases (some look like IBM AT style cases).
If you need any ROMs dumped or whatever, just let me know - the Redstone is still running great (I only tested it a couple of days ago).
Cheers,
Mike
You got it! Amazing!
Yes, I have disconnected the joystick .
I have never been a game player so I did not know why there was a joystick connected to my old Apple //.
Mystery solved. Thanks.
Yves
What a beast and what a resurrection.
I have bats and starlings' nests in my attic, and I was wondering what's in yours? :)
Yes it's the same board in revision B instead of D. You have a prototyping area on the keyboard side.
And yes, there was also a joystick hidden inside.
I had forgotten that it was the joystick that allowed us to use a standard keyboard.
Thanks for sharing your video.
Yves
I bought the Redstone from eBay in the condition it was shown initially in my video. I have no idea as to where it had been stored prior to me getting hold of it, but it must have been in a barn/shed as it was in a really bad way (full of spiders, dirt, rust, etc).
Hi Mike,
That’s exactly the motherboard I’m having trouble with. I watched your excellent repair video. I noticed the following: When the keyboard is connected to the blue keyboard connector in your setup, the chip to the left of the LS373—which is a TCK448 on mine—isn’t plugged in. That might be why all my attempts failed. It would be a great help if you could send me the contents of your keyboard ROM. And if you could let me know how the jumper is set on JP1 and whether jumpers JP2 and JP3 are closed.I would really appreciate that.Thanks in advance
Wolfgang
The timer 555 is probably not well studied in Germany?
Actually it is the poor motherboard that is having trouble with you. It was workig fine. Don't trouble the trouble until trouble troubles you.
Hi Wolfgang,
It might take me a few days, as I will need to get the Redstone on the bench and tear it down to get the keyboard ROM out. I will also take close-up photo's of the jumpers that you were interested in.
I will post back once I've had a chance to do the above.
Cheers,
Mike
Hi Mike,
That's very kind of you. I'm really looking forward to it.
Best regards
Wolfgang
Do you think the EPROM contents would help? I was watching this topic in which for the past almost half a year the majority of applefritter resident experts gave their advices. I knew the correct answer, but being banned several times on this very forum (I don't count the accounts I had here, it doesn't matter) I am reluctant to help. Maybe owad would help instead of lying my last ban was for a month or two (it was in fact permanent)? I doubt he will. I have a rule - the overall/mean competency level of any given forum is in inverse proportion to the forum's censorship level and rarely overtakes the competence level of the moderator/owner himself. You have to choose.
Had you asked me in another forum, I would have vectored you in the right direction immediately.
Anyway, I am probably making an exception one last time and will help. No matter what jumpers you set, or whatever EPROM you install, the motherboard, as pictured, will not work with a //e keyboard. Why? The answer is in your pictures Wolfgang that you posted some half a year ago. Look at them? Look at the solder side wiring to the keyboard controller. Then look at the datasheet of the keyboard controller you installed in the socket. That controller does not belong to this motherboard and the PCB is wired for a different keyboard controller. Maybe you are still in doubt? Look at the power tracks to pin 1, pin 5 of the keyboard controller. Now look at the datasheet of the chip you plugged in. Too pity this deceiving picture of yours cannot be easily removed, now all the AI plague will repeat and amplify your deception, and decades after your post people with such motherboard will be misled the PCB was designed to work with the pictured keyboard controller. I hope they will use their brains more efficiently and will figure out the problem much faster. I am no longer disappointed by Germans.
No future human or AI will be misled, if a simple explanation is provided such as: the KB3600-PRO is the correct keyboard controller with the correct pinout for this motherboard.
KB3600-PRO.png
Source: https://www.youtube.com/watch?v=m_-eu9YHbsk&t=899s
OK, so it turns out I dumped all the ROMs back in 2017 when I was doing the restoration:
Also, here are some better pics I took of the motherboard back then also (it should show you chips, jumper settings, etc):
20171014_191404.jpg
20171014_191549.jpg
You'll notice that the ROM chips are missing, as I must have been creating the ROM dumps when these photo's were taken. :-)
I have more photo's if there is anything else in particular you need to see.
Cheers,
Mike