MK14 Programming Interface

[SiriusHardware]

Uploader PCBs (along with Ortonview PCBs) have just gone in the post to Tim and Mark today, Saturday.

Mark, sorry but I did not get the opportunity to fit optos - had they arrived a day earlier I would have taken yours to work and populated it with the TLP185s which we have in abundance there.

[SiriusHardware]

Thinking about making send14 configurable in a more friendly way, we could make it so that any 'switch' command issued when send14 is run creates a config file which is always looked for first when the program starts, so

If no config file found and no optional switch commands issued, run using the settings embedded in the program.

If switch command issued and no previous config file found, create a new config file with all settings including the new setting saved in it and apply the switch command setting for this run

If there is an existing config file and there are no switch commands issued, run using the settings found in the config file.

If there is an existing config file and there is a switch command issued, update the config file with the new setting and then run using the new setting.

The point of this is that it lets you issue switch commands on a one-shot basis, after which the program continues to run in that mode until you issue another switch command so you don't have to remember to type e.g 'send14 moonland.hex OS=old' every time you run it. After the first time, the config file will 'remember' that your preference is to run in Old-OS mode.

Examples of parameters we might control in this way:

-OS output mode (Output keypresses as required by the old or new OS)

-Speed parameters, either singly or as a set

-Standard MK14 or JMP MK14 (only for use with opto interface with more optos than the current one has)

-VDU inactive / active (Increase all timing values by x% when an active VDU is connected).

-4.00MHz / 4.43MHz (select between two sets of timing values, one optimised for 4MHz machines, the other for 4.43MHz machines).

[Timbucus]

If you do that then it becomes easier to have a profile that changes all parameters as at least several of those items are different per machine so you could do send14 -P1 and that just saves that profile to DEFAULT and uses it from then on - so you can edit it - so you could store known profiles in the release but, still make it easy for people to tweak locally if they need without editing.

[Timbucus]

Obviously as you say send14 will create default if there is not one of the most likely.

[Mark1960]

Originally Posted by SiriusHardware

Uploader PCBs (along with Ortonview PCBs) have just gone in the post to Tim and Mark today, Saturday.

Mark, sorry but I did not get the opportunity to fit optos - had they arrived a day earlier I would have taken yours to work and populated it with the TLP185s which we have in abundance there.

No problem, fairly sure I can get suitable optos from a local shop here.

[Timbucus]

From OrtonView thread --

Originally Posted by SiriusHardware

Tim, when you get a bit of time would you be kind enough to draw a sketch of your Plus-three (optocouplers) interface so I know which extra GPIO pins you used for which of the extra three, and which three connections on the MK14 edge connector the extra opto go to? I would guess you left the original thirteen routed as found and just added the others in to the gaps, but maybe not.

Is this what you want?

[Slothie]

Hmm interesting. Seems like a PCB with this layout would be easy, just not fit the col 7 & 8 optos if you don't need them, then change the pin mapping in the software to suit the kind of board you are connecting to.

[Timbucus]

I also needed the extra optos to allow me to use them as pull downs for a resistor pack in my Triton adapter as I use the same board with a small conversion PCB to type ASCII into it - this would also work with things like an Apple 1 etc.

[SiriusHardware]

Ref #46, exactly so. Since you (Tim) have already made yours as per that diagram, that can be the new standard opto interface diagram on which Slothie can base his V2 uploader PCB, should he get to the point of doing one.

We'll then make a new 'mainstream' (V2?) version of send14 which can work with both standard and JMP edge connections through the same 15-opto interface.

I think at that point we'll ask for the original thread to be reopened so it can all be put into one chronologically linear thread, similar to Slothie's epic 'MK14 schematic revisions' thread.

[SiriusHardware]

Progress: (Attached).

Just need to make up the connecting cable + plugs for each end. I have to say this PCB makes the interface an absolute doddle to build, thanks, Slothie. There's no excuse for anyone not to make one now.

As you can see I used SMD optos because I have whole reels of them here but it would no doubt be even quicker to build with DIP optos, the SMD ones have to be positioned quite precisely so each leg just reaches the nearest pad.

[Timbucus]

Looks very neat Sirius - I have SMD ones anyway on order - pressed submit before reading post so will need to do the same...

PCBs have arrived today - Thanks both. I was missing many bits though for that and the Ortonview (three types of PCB mount phono I have - none fit!) so Farnell order just sent for everything I do not have.

[Slothie]

Lucky the SMD Optos have the same pinout! Might try a "dual footprint" on future boards if I make one, as I noted the SMD optos are easier to find and usually cheaper.

I see that you chose to link over the reset jumpers, I suppose its still usable on your original with an appropriate cable.

[SiriusHardware]

I see that you chose to link over the reset jumpers

I'm intending to dedicate this one to the issue VI which is the MK14 I use 98% of the time now. My original MK14 is more or less 'retired' now because the issue VI is just so much more usable and it isn't a valuable historic artefact like my original issue II is.

The old machine will still be wheeled out and powered up from time to time, I'm very, very fond of it but I don't want to stress it out any more than necessary. For programming that, I have my original vero prototype of the Pi uploader or the Arduino version I built, both of which have the reset output on flying clip leads.

[Slothie]

Well its going to make writing that moon landing program you prototyped easier having a dedicated uploader once you get the Ortonview working...

[SiriusHardware]

Actually, I thought Tim was going to do a full-on MK14 Text Adventure which ingeniously uses a serial EEPROM to hold all of the map, location texts, objects, vocabulary and possibly even location graphics as per 'The Hobbit'. That right, Tim?

As we still don't have an official or agreed keymap for a QWERTY keyboard, we could maybe bit-bang comms for a PC PS/2 keyboard.

[SiriusHardware]

The screen printing for the 40-way connector indicates that the connection is for a Pi-Zero. Out of the box, the Pi Zero doesn't usually come with anything soldered into the GPIO port pads so the fastest and easiest way to dedicate one for this purpose is to solder a 2 x 20 (40 way) female IDC PCB connector to the underside of the Zero / Zero W. (image 1).

However you can actually connect the interface to any 40-pin Pi which has male pins fitted and pointing upwards, including a Pi Zero or Pi W, by using a short one-to-one female to female extension lead (image 2).

Although I usually use a Pi Zero W, I have also tested the interface and 'support software' on a Pi 3 connected as shown in the second image.

Taking things further, if you don't mind writing or adapting software yourself you can also use some other microprocessor or logic device to drive the interface, as long as it can output either a 3V3 or 5V0 common supply, and as long as its individual I/O pins can sink enough current to 0V to power one LED each. When the interface is operating, no more than two of the 13 optocoupler LEDs are ever powered at the same time.

[Slothie]

I forgot to actually say that I soldered the connector to the underside of the Pi Zero.

I have also been thinking about making a board to adapt it to a Pi Pico I just have other things to do at the moment!

[Slothie]

I like the idea of connecting an SPI EEPROM to the flag and sense pins so you can do a slideshow drawing from the EEPROM. I like the idea of a text adventure with "canned" graphics too. It would have to be fairly simple I guess!

[SiriusHardware]

Well, Tim is a genuine text adventure Grue... er, I mean... Guru... and also a bit of an SC/MP nut so it's hard to imagine anyone better equipped to try.

Problem is, like you, he always seems to have far too many plates spinning. We'll probably have to let him repair that Heathkit machine first.

[Timbucus]

Originally Posted by SiriusHardware

Actually, I thought Tim was going to do a full-on MK14 Text Adventure which ingeniously uses a serial EEPROM to hold all of the map, location texts, objects, vocabulary and possibly even location graphics as per 'The Hobbit'. That right, Tim?

As we still don't have an official or agreed keymap for a QWERTY keyboard, we could maybe bit-bang comms for a PC PS/2 keyboard.

I will get right on it, after the PICL, COSMAC ELF, Ortonview, PI Uploader, SOFTY, Triton 2708 EPROM programmer software ROM and getting the Triton's case made and installed, Fixing the H9, Finding the IRQ Bug on the H8 - I have yet to build my Acorn System 1 or ZX80 as well. There is a 77/68 on its way (as my 6800 system instead of the System 68 I was building so I can have a Rack Scrumpi as JMK originally envisaged it) and I need to get Phil's QuidBoard working for my Z80 uP dev unit. Then we have reverse engineering the Scrumpi 3 video (via an adapted OrtonView to simulate it) and building a real one and developing the extended Network/Serial driver for the Next in time for launch of KS2. I also need to finish the Dragon 32/64 upgrade that has the 80 column card in it and get the lowercase rom running. Then there are all the repairs like my BBC, several Spectrums and no end of other stuff...

I still think a real scanned keyboard addon on the port is the best though as it will be authentic to the time - they must have had a prototype.

I recently game across a quite advanced adventure game from 1978/9 on the KIM-1 that only used the Hex Keypad and normal display - having limited verbs basically - far more then the Maze game from Compliment and Add as actually what you suggest may be possible - descends into another rabbit hole muttering "no time", "no time"