SC/MP National Industrial Basic Language (NIBL) Retro

[Phil_G]

Hi Martin, if you fancy an easy option at reasonable cost, there is a kit:
https://www.budgetronics.eu/nl/bouwpakk ... a-25922-20
No connection, just some other pic enthusiasts
Cheers
Phil

[Martin]

Thanks Phil,

I'd seen that kit, but wondered about VAT/import duty/handling charges being added, as it's coming from the Netherlands. I've ordered one now though.

I might still try to build one up with the larger 16F877A chip - I've got most of the bits hanging around, just need to obtain some seven segment displays.

If I get into the Scamp stuff, I might try to program an emulation on a Raspberry Pico - that would be capable of running blazing fast (for a Scamp), but I'd have to include a 'turbo mode' on/off switch, so it could still run at the correct speed for serial communication and other time-critical operations.

[Phil_G]

The 877 version is better cos it has the emulated Flag outputs and sense inputs, missing on the 876 version.
Unforch I dont have a spare PCB but I do have Philipou83's gerbers, they're on my sc/mp page under the heading
"Karen Orton's PIC14 - a Science of Cambridge MK14 clone:"
Actually if you do order a batch, I'd buy one from you as I dont have a spare for that project
Latest PIC14 firmware is there too, same code for either version
Cheers
Phil

[Martin]

I've ordered 5 of the 877 board, and 5 of Simon's 876 board. Both in purple!

I'll let you know when they arrive. The smaller ones cost me about £4.50 each, and the larger ones just over £6 each.

If you know anyone else who wants one of either type, let them know I've got some on the way...

Edit. I should have checked before ordering. Philoupat's (877) board is laid out to take the vintage Antex SK-3-307 9-digit 7-segment calculator display module. I'm going to have to make an adapter board to unscramble its 17 pins to suit more modern (and cheaper) displays. I think I'll go for eight separate 0.28-inch 7-segment displays.

[Phil_G]

No its ok we use a display board that takes these displays: https://www.ebay.co.uk/itm/265676476236
Chris Oddy does the display PCB, free with any other purchase, about halfway down this page:
https://www.theoddys.com/acorn/shop/mk1 ... _shop.html
The SIP pinout is standard, most old common cathode calculators Texet etc fit. Note the very left pin isnt used.
Its usual to fit a header so the display can be unplugged.
I use the same display PCB & 7segs on both my 'genuine SC/MP' MK14 repros:

[Martin]

Oops. I'd already designed and ordered this monstrosity before I saw your post.

But perhaps it's just as well, because I'd already ordered some of the correct size for that (0.28-inch) 7-segment displays.

The board is 104mm wide by 25mm high. So wider than the Mk14 itself - the PIC version anyway, and I guess the vintage one too. I'll bend the header pins so it sits at a comfortable angle to the main board for viewing - I don't think it will clash with any other components or connectors - but I could always raise it up higher if necessary.

It was a cheap board, so I've ordered twenty of them - just in case any venerable Mk14 programmers with ailing eyesight might want one!

[Timbucus]

My eyesight is pretty poor - large displays are really useful when running demos of the MK14 so I do the same as Phil. I may take you up on an even bigger one as well..

[Martin]

No problem Tim, once the bits have arrived (it might be after Christmas now, for some of the components from China) I'll build some display modules and post some pictures/YouTube videos of them working in this thread.

Then I can post one to you, and to anyone else who wants one.

Do most people have a 19-pin display socket on their Mk14, and male header pins on their display board, or vice versa?

[Phil_G]

Mine are sockets on the PCB, pins on the display.
I'm not sure if Trevor Hamblett ever posted his display gerbers, or if its just an agreement with Chris.
It does make a very neat job with .28" displays.

Incidentally Martin, did you see Karens Appollo "DSKY" version of the PIC14?
https://www.vintage-radio.net/forum/sho ... post884338

[Martin]

All the bits arrived, and I got them working.



I forgot to peel the protective film off my 'Big Display' 7-segment LEDS before I filmed that. It's easily the clearest one to read in real life, though it doesn't look like that in the video.

For the Philoupat design I swapped out the BC547 NPN transistors (common cathode display drive, and keypad column select) for N-channel MOSFETs after reading Karen's comments about display ghosting when running some programs - and her recommended fix of fitting 10nF capacitors across the base resistors to make the transistors switch faster. The FETs switch really fast, and there's no need to fit base resisitors - I just fitted wire links.
Simon Merrifield's design has a ULN2803 Darlington driver chip in place of the transistors, and I built the Budgetronics kit up as supplied with the standard BC547 transistors and no 'base capacitors'.

Let me know what bits you'd like, guys. I've got 4 spare PCBs for each of the Simon Merrifield and Philoupat designs, and 19 spare 'Big Display' PCBs. I also have enough 7-segment displays, FETs, chips, etc. to build up some short kits, or assembled boards, if that's what people want. I'll work out some prices if there's any interest. I'm not looking to make any money from these - just recover the cost of the parts.