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Old 20th Jul 2021, 3:47 pm   #1
Slothie
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Default MK14 Programming Interface

I just built one of Siriuses Programming Interfaces using the send14 program here and it all seems to be working! I suppose now technically my MK14 is connected to WiFi!
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Old 20th Jul 2021, 4:05 pm   #2
Timbucus
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Default Re: MK14 Programming Interface

Oh cute - did you design a PCB in the end?
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Old 20th Jul 2021, 4:06 pm   #3
SiriusHardware
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Default Re: MK14 Programming Interface

You didn't have to fettle any of the time delays? For some some reason most people do. I'm guessing your issue VI has a VDU friendly 4.00Mhz crystal, which should theoretically make it even more sensitive to programmer overspeed - or maybe you currently have a 4.43MHz crystal fitted?

When you come to connect OrtonView the system slowdown caused by OV will mean that you will have to throttle back the keying speed of the uploader a little bit, unless you take pains to disable OV during uploads.

I see you've used a direct connection to the reset input (only available on your issue VI) for maximum neatness.

Did it 'Just work?' If so, yet another triumph for your board designing skills.

Last edited by SiriusHardware; 20th Jul 2021 at 4:13 pm.
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Old 20th Jul 2021, 4:11 pm   #4
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Default Re: MK14 Programming Interface

I was going to say that if you plan to use OrtonView, you'll need to round up and fit the additional RAM but of course I'm forgetting that your version of OrtonView already has a VDU friendly 1.5K of RAM on it.

Some of the 'Legacy' software for the VDU was designed to run in I/O RAM with both the main and 'extra' RAM used as screen RAM, so it might be an idea to fit it anyway.
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Old 20th Jul 2021, 4:47 pm   #5
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Default Re: MK14 Programming Interface

Quote:
Originally Posted by Timbucus View Post
Oh cute - did you design a PCB in the end?
The PCB is a cobbled together thing that started life as a protoboard layout and was turned into a PCB. If I was doing it again I would make a number of changes, like using the edge connector footprint like I did in the Ortonview instead of a dupont header with cables so I could just solder the edge connector on to the circuit board, and the Pi Zero W hangs over the edge of the board so you can't put in a securing bolt, and its a bit of a squeeze to get the optocouplers under it to fit because they are close to the Pi connector..... But it all just fits and it worked.
Also the GPIO connector is soldered onto the bottom of the Pi Zero, so using a ordinary Pi would be hard, although you could probably do something with a ribbon cable and a couple of IDC connectors to get around that if you are careful with the pin mapping and orientation of the connectors.

Quote:
Originally Posted by SiriusHardware View Post
You didn't have to fettle any of the time delays? For some some reason most people do. I'm guessing your issue VI has a VDU friendly 4.00Mhz crystal, which should theoretically make it even more sensitive to programmer overspeed - or maybe you currently have a 4.43MHz crystal fitted?

I see you've used a direct connection to the reset input (only available on your issue VI) for maximum neatness.
.
No, I left the time delays as standard. I am using a 4.43MHz crystal too. Guess I was lucky! I used the "key14" program to test all the keys worked, then tried send14 with the slothie.hex file. I discovered that the checksums put into the file (probably by my bin2hex program) were wrong, so I had to (temporarily) disable the checksum check in send14.py but I'll redo the checksumming properly and re-instate the check in send14. With permission I might even tinker with send14 to add some option arguments for timing etc.

The reset connections are brought out to a 4 pin header (which I've had to make right angle because it sits under the Pi ) so you can either jumper it with a couple of links like I have or connect 2 dupont style female connectors connected to croc clips if you dont have an Issue VI.

As for the I/O Ram, as I was typing this it occurred to me it would be easy to make a small board to take a couple of 2111/4 RAM chips that plugs into the RAM/IO socket and gives an extra 256 bytes for people without an 8154 (assuming you don't need the I/O)....!

If I can manage to find a way to get stuff posted to people (tricky at the moment due to being in a care home) I can post a board to anyone, as I accidentally got 15 made which is about 14 more than I need. If I work something out I'll announce it here. As I say its not perfect at all but was done quickly because I got the chance of some free PCBs!
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Old 20th Jul 2021, 5:31 pm   #6
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Default Re: MK14 Programming Interface

A few points arising:

The fact that you've used a wired connection rather than a 'hard' one for one connection accidentally makes the PCB equally JMP-replica-compatible - you just need to make the connections differently at the MK14 key connector end.

I suppose If you'd made the layout direct one-for-one compatible with the 'Legacy' layout seen on original MK14s, Martin issue V replicas and your own issue VI you would still have the option of soldering wires to the edge connection on the interface PCB and taking them to an edge connector wired as per JMP connection order.

My prototype also has the 40-way connector coming out of the bottom of the Pi Zero - since they are usually supplied minus the 40-way male connector it's up to you how to solder one in, but I agree that the form factor chosen makes it slightly harder to use a 'big' Pi which will have the 40-way male connector already fitted and pointing upwards. My solution there was to fit a 40 way male pin connector to the opto PCB, pointing upwards, and use a short ribbon cable with 2 x [2 x 20) female connectors on the ends to connect the opto interface to any standard 40 pin Pi including a zero with the pins fitted pointing upwards.

If you do a V2 consider redesigning it as a 'hat', Raspberry's equivalent of the Arduino 'shield', so that it will fit directly on top of any Pi. If you want to get it into the same form factor as a Pi Zero though, it might have to use SMD versions of the optocouplers.

As regards the send14 'support software' I have stated several times in the past that the project is public domain and that anyone is free to improve it in any way they like - I would love to see a GUI version of send14 but I just can't get interested in TkInter for long enough to do anything with it.

Let me also state for the record that I would be perfectly OK with you selling these opto interface PCBs either as bare boards or kits, in fact I would appreciate the opportunity to buy one myself.

Re: the problem with checksum verification not working, does the uploader load the included Message.Hex and Moonland.Hex files OK? It's not impossible that I might have broken something else when I fixed the 00 checksum bug a revision or so ago.
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Old 20th Jul 2021, 5:44 pm   #7
Slothie
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Default Re: MK14 Programming Interface

Quote:
Originally Posted by SiriusHardware View Post
A few points arising:

Re: the problem with checksum verification not working, does the uploader load the included Message.Hex and Moonland.Hex files OK? It's not impossible that I might have broken something else when I fixed the 00 checksum bug a revision or so ago.
Yes, every other hex file is fine with it. Its definitely a bug in my bin2hex because I tried a different binary file and the checksums were wrong in that one too!

I'm going to see if can get some kind of cheap laser printer, then I can buy postage online, print it out and put packages in the postbox and won't need to get to a post office. Then I will be able to send out PCBs etc! I had a quick look on ebay but nothing grabbed my attention. I might be able to connect to one of the homes printers which will be less convenient but might be an option....

Last edited by Slothie; 20th Jul 2021 at 5:48 pm. Reason: Postal
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Old 20th Jul 2021, 6:05 pm   #8
SiriusHardware
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Default Re: MK14 Programming Interface

If we were to do it old-school and send you some self addressed and stamped padded envelopes, could that work?

From what you say your residence does have a postbox for outgoing mail provided you can find a way to stamp, address and package it?
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Old 20th Jul 2021, 6:30 pm   #9
Slothie
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Default Re: MK14 Programming Interface

Well I can get the staff to drop post off at the post box, I think I also get close to a postbox when I go out for a walk with one of the carers from time to time, so yes if I had some post paid padded envelopes then I could send them. presumably that would depend on weight, but a PCB or 2 isn't much...
I think any post that gets sent out usually gets dropped in the box by the manager here, so if there's not too much I can get away with giving to them
I'm sure it can be worked out!
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Old 20th Jul 2021, 6:48 pm   #10
SiriusHardware
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Default Re: MK14 Programming Interface

From your point of view / the residence's admin point of view I think probably one thick package outgoing from you and then distributed onwards by one of us would be the easiest arrangement for you.

Tim probably thinks I'm about to volunteer him for the job, but I would be happy to do this. I would suggest waiting until the OrtonView PCBs also turn up and in the meantime maybe we can gather expressions of interest which can be converted into a guesstimate of outgoing weight / cost.
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Old 20th Jul 2021, 7:10 pm   #11
Slothie
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Default Re: MK14 Programming Interface

That sounds like a plan. I'm going to need 2 of the 5 Ortonviews so there are 3 up for grabs and up to 14 programming interface boards !!
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Old 20th Jul 2021, 7:20 pm   #12
SiriusHardware
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Default Re: MK14 Programming Interface

I (Sirius) would definitely like one OrtonView PCB and one programming interface PCB.

Mark1960, if you want either / or, it will not be a problem sending them to Canada. The least we can do after all your help in the epic PET repair thread, and for keeping us entertained with your leading edge SC/MP projects.
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Old 20th Jul 2021, 7:38 pm   #13
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Default Re: MK14 Programming Interface

Same here - one of each and happy to be volunteered if needed.

As regards the JMP compatibility I just added three more opto isolators and modified the code to use the correct ones... That made it more flexible when I did the Triton as I needed more lines and also to simulate the 40 key keyboard they were proposing...
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Old 20th Jul 2021, 7:49 pm   #14
SiriusHardware
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Default Re: MK14 Programming Interface

I can't help but wonder what Slothie intends to do with two VDUs... a dual-screen MK14...?
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Old 20th Jul 2021, 9:11 pm   #15
Slothie
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Quote:
Originally Posted by SiriusHardware View Post
I can't help but wonder what Slothie intends to do with two VDUs... a dual-screen MK14...?
Its really just contingency for when I break one of the boards, lift a track, set light to something with a short.... So if I get it working first time there might be another up for grabs!

There will almost certainly be a V2 board for people feeling left out and when I get feedback on what bits need changing or improving.

I cant imagine how the bus arbitration would work for a dual screen Ortonview.....maybe thats a subject for Marks expertise!
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Old 20th Jul 2021, 9:15 pm   #16
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Default Re: MK14 Programming Interface

Quote:
Originally Posted by SiriusHardware View Post
I can't help but wonder what Slothie intends to do with two VDUs... a dual-screen MK14...?
Its always good to have at least one spare as it makes it less painful to hack the first one during development.

If nobody else wants the third spare orton view pcb then I would be interested, but please give priority to anyone else in uk first.

Not so sure about the loader as I donít have a Pi and my opto couplers are 6 pin, but it probably wouldnít increase postage to include one and
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Old 20th Jul 2021, 9:26 pm   #17
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Default Re: MK14 Programming Interface

Quote:
Originally Posted by Slothie View Post
I cant imagine how the bus arbitration would work for a dual screen Ortonview.....maybe thats a subject for Marks expertise!
Iím still not sure if I can get the bus arbitration to work with a single orton view and multiprocessor. Simple enough to put an OR gate between NENIN from orton view and NBUSRQ to provide NENIN to the SCMP, but not sure about the effect on ILD and DLD.
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Old 20th Jul 2021, 9:33 pm   #18
SiriusHardware
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Default Re: MK14 Programming Interface

Quote:
it probably wouldn’t increase postage to include one and
..I think there was a glitch in The Matrix there.

The same interface PCB can be wired to an Arduino or almost anything with 13 output port pins (ie, medium range PIC?) as long as the port pins have enough current sink capability to drive LEDs.

DeltaAlpha52's Arduino 'fork' of the uploader uses more or less exactly the same interface circuit.

Go on, you know you want to. It makes a world of difference to be able to fire code into the MK14 in a matter of seconds, they're so much more fun to play with when you can do that.
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Old 20th Jul 2021, 9:56 pm   #19
Slothie
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Default Re: MK14 Programming Interface

Yes, it does use 4 pin optocouplers, the type I used were PC817 (Or LTV-817/EL817...) because they were cheap on eBay
I might try wiring one of my boards to a Pi Pico because thats 3.3v as well and runs Micropython...
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Old 20th Jul 2021, 10:12 pm   #20
SiriusHardware
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Default Re: MK14 Programming Interface

I have a Pico too but haven't done much with it as I would rather programme it in 'C'- they haven't got the working environment for that language set up very well yet, although there is a script which sets everything up on the (Linux Computer) Pi if you don't mind using that as your main development machine. I really wish they had not used the 'Raspberry Pi' brand name for the Pico. The Arduino IDE is supposed to be bringing in support for the Pico as well as a few other PCBs which will use the same microcontroller.

My impression (unconfirmed) is that the Pico has quite a lot of onboard RAM and is also very fast so you could do something like the MK2 Arduino version (which currently uses an external SRAM as a serial buffer) but try using the internal RAM on the Pico instead.

If just not having the right optocouplers is an issue for Mark, fear not, I can easily populate the opto positions (if desired) by soldering SMD versions to the through hole pads on the upper side of the PCB - wouldn't add much to the weight and I have more than enough of them lying around at work.

As regards 3.3V vs. 5V drive, the optocoupler LEDs are 'lit' for such a short time during each key press that running them from 5V through 330R doesn't stress them much, so I did not bother to change those values for the Arduino version. The reset opto is lit for longer, but only rarely.

Last edited by SiriusHardware; 20th Jul 2021 at 10:19 pm.
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