Re: MK14 Programming Interface
 

So something like this?

Re: MK14 Programming Interface
 

Looks OK, although I think the 'ampersand' and 'caret' shifted characters need to be swapped over.

On the keyboards I find lying around here, shift-6 is 'caret' and shift-7 is 'ampersand' - if you are buying key sets which are already legended, or two sets, one legended and one not, it helps if your chosen key layout matches as many of the off-the-shelf legended keys as possible.

Re: MK14 Programming Interface
 

Looks really great we are also missing / : ; ? and @ from having a home.

If we do use SHIFT for some Control Characters it should be the ones most likely needed and move off other functions if we can where they conflict.

If we cannot get custom keycaps then maybe where the other characters are is relevant as well for muscle memory e.g. . and , are next to N and M on most keyboards so would be on them with < > being on H and J as shifted. By that logic : and ; and maybe @ would be on JKL etc....

Not really worried as there is no way to decode other than a lookup table anyway so preserving anything except what makes it easy for humans will be pointless.

Re: MK14 Programming Interface
 

OK just built the PCB up and it works - had one fault that 'e' the Column for 3 and D did not work - I had to flow a lot of solder through the hole so maybe a board fault - something to watch out for but, easy to find with key14 trying various keys!

The connector I had did not have the top pin to wire through Ground though so no reset available. But make a neat job I think with no need for flying leads - no use on the Triton or the JMP board but, suits me for this specific use.

Attachment 238967

Re: MK14 Programming Interface
 

Bit late to suggest it now but as there are two unused connections in the middle of the connector you could perhaps have removed one of those and moved it to the top (0V) position. Looks neat though.

I think Slothie plans, in the event of a Rev 1.1, to make the MK14 keypad connections edge-connector 'fingers' so that any double sided 0.1" connector can be soldered onto the edge of the board.

Re: MK14 Programming Interface
 

I guess that's code for 'So when do we get the version with 15 optos?' ;)

Re: MK14 Programming Interface
 

I suppose it wouldn't be hard to make one that will operate a 10x4 matrix, with the extra reset opto, and people could fit whatever optos they require.
How big a matrix do you need for the Triton?

Re: MK14 Programming Interface
 

Only 8x1 as it loads full ASCII characters - I suspect that might be common on older machines.

Re: MK14 Programming Interface
 

So that means you need either 8 column optos or 8 row optos - maybe both, if you don't know in advance whether the target system needs to pull the lines up or pull the lines down.

Also the polarity matters, so you need to cater for the possibility that the target system might have a large number of driven lines and a small number of read lines, or a small number of driven lines and a large number of read lines.

It might also be useful to have up to two additional undedicated optos (like the reset opto, the output of which is not specifically connected to anything) - these would be for connecting straight across the CTRL and SHIFT keys on an alphanumeric matrix keypad, so that the uploader could press one of these keys at the same time as pressing any other key on the keyboard via the more usual row / column joining method.

Re: MK14 Programming Interface
 

If I were to make a full 40 key keyboard we might need a full uploader... just saying!

You could use the existing uploader PCB if you fitted only U2..U9, connected the keyboard to the column lines, fitted pull-down resistors to the columns and connected the common track between the optos (e.g. Pin 3 of U10) to +5v of the Triton. You could probably use the reset opto to provide the strobe in a similar manner. But I suppose after you've butchered the PCB that much you could have done the same on stripboard!

Re: MK14 Programming Interface
 

Sounds good but, adds a lot of complexity - I just used some pullups on the little adapter board for the Triton - I used one of the Optos to source current and left three unused. I think we discussed how we could do it for things like the SCRUMPI and I am about to tackle it for the Cosmac Elf and also the 77/68 that has just joined the project pile.

Re: MK14 Programming Interface
 

To cope with any likely alphanumeric matrix keyboard I think 8 column + 8 row optos, one lot of 8 with emitters and one lot of 8 with collectors connected to a common interconnecting rail as per the current 4 + 8 of the present Pi-uploader - turn on one of the column optos and one of the row optos to press any single key in a matrix of up to 64 keys, and also at least two undedicated optos to hard-connect across the row / column intersection of CTRL and the row / column intersection of SHIFT so that the interface can press either of these keys by energising a single opto at the same time as it is energising a pair of optos to press any other key. That's still only 18 optos / GPIO pins and the same circuit could still be used, with appropriate GPIO / opto mapping, for the Pi-uploader.

For Triton or other computers expecting 8-bit parallel input from the keyboard just use the 8 row optos or 8 column optos (as appropriate) and one of the undedicated single optos for the strobe.

One interface to rule them all.

Re: MK14 Programming Interface
 

Hi all been a while since I've been here - but the MK14 has now come to the top of my project list again.

Would like to replace my veroboard version of the keyboard programming interface so is there any PCBs left? and is the design files available for changing - i.e. to plug into the Arduino interface.

Re: MK14 Programming Interface
 

I do have a number of PCBs left over.... If you want to send me a self addressed and postage paid padded envelope DM me and I'll give you my address and send you one for free!. The envelope will need to be big enough to take a 80mmx60mm pcb with postage for a weight of ~40g. Unfortunately at the moment I am not in a position to get to the post office to post items but I can get them dropped off into a postbox!

Re: MK14 Programming Interface
 

To answer the other question I haven't got the design files on a public server at the moment, but if there is interest I could put them on bitbucket.

Re: MK14 Programming Interface
 

Slothie's PCB will work perfectly nicely with an Arduino if you fit 2 x 20 upward facing male pins in the place intended for the Pi connector and use female to female DuPont leads to connect the board to to the male pins of an Arduino - or indeed a Pi Pico - instead of a Pi.

Re: MK14 Programming Interface
 

Oops - correction to the above, the connections on the Arduino are female of course, so you would need male to female DuPont jumpers, not as per previous post.

Re: MK14 Programming Interface
 

just one minor thing with the PCB, I noticed that pin 1 of the opto-isolators isn't all that clearly marked.
Normally I would make pin 1 a square pad, but I seem to have forgotten to on this board.

Pin 1 is indicated by the barely visible silkscreen "dogleg" next to the pin, which is top right on the horizontal row of 9 isolators and bottom right on the vertical row of 4 isolators. (see pic)

Re: MK14 Programming Interface
 

Hi

thanks for the PCB and for the details of where pin 1 is for each of the opto-isolators,

I gather P2 is designed to allow use of either "flying leads" for the original MK14 or direct connection for the newer ones - where reset is taken to the edge connector.

Cheers
David

Re: MK14 Programming Interface
 

Yes, for the Issue IV put jumpers across, others will need flying leads to clips to attach to the reset capacitor as below.