SC/MP introkit + KBkit =MK14 - UK Vintage Radio Repair and Restoration Discussion Forum

audiokit · 4th Jun 2023, 9:04 pm

It was some time ago since I posted but this does not mean there was no activity.
Some time agon I got the plan to make my second SC/MP kit but now I wanted to add the KBkit. I got myself a Novus 831 calculator just to see if there was anything needed to rebuild it. I did manage to connect the 831 with coloured flatcable to the introkit. Unfortunately some of the keys proved to be unreliable. The calculator did not need any modifications to show the start screen, so the 2 remaing calculator chips were left on the PCB. You also can see that if you watch Curious Marc's youtube video when he lifts the lid of his tin box.

So my new plan was to make a reliable keyboard with bubble leds to make it feel a bit like the real calculator.

I could see that the MK14 SCIOS-1 is exactly the same as the SC/MP KBkit ROM. To be sure I just programmed the SCIOS-1 bin file on the eprom of my kit and voila, it did run! So Curious Marc should not have typet in all the data to recover his MM5214 ROM.

To be sure the SC/MP introkit + KBkit were completely compatible, I loaded the SCIOS-2 and after connecting SENSE-A to ground. it worked just the way my MK14 does.

I add some pictures of my build hoping it will stimulate others to build these small single boards as well.

SiriusHardware · 4th Jun 2023, 11:27 pm

It's actually quite well known that 'SCMPKB' - the OS for the National Semiconductor Introkit + Keyboard and display - and the original / old OS for the MK14 are one and the same but since the MK14 was only really well known in the UK I would not necessarily expect CuriousMarc to know that, besides which he had a printout of the SCMPKB ROM code right there with the machine so the logical next step in the story was to take that code and type it into a programmer's editor, program a new chip, wire it in in place of the original PROM and see the machine spring to life.

It did occur to me a while back that it should be possible to run the 'new' / improved MK14 OS on a National Introkit + keypad and display, but you are the first one to ever try it as far as I know.

As it does work, it follows that coolsnaz2's modified version of SCIOS2 with the fast serial loader routine in place of the cassette tape routines should also work in the National Introkit + Keypad + Display.

Phil__G · 5th Jun 2023, 12:25 am

A work of art Benny! very nicely done.

audiokit · 5th Jun 2023, 5:58 am

Thank you both for the comment and compliment!

The next project will be with different boards that are modular all on Eurocard format (as the example I showed) and connected via a backplane.

The SC/MP + eprom will then be placed on the main card. At the bottom of this board will be the buffers to improve the fan-out. My intention is to connect the cards I made for the Elektor SC/MP in the intro kit/MK14 computer.

It is still possible to run MIKBUG in addition to SCIOS 1 and 2, if the eprom is changed. I have to test if the ROM/RAM connection from the KBd part has to be switched to ground again, that was the only thing I had to change to run SCIOS-1 but I did not try yet to run MIKBUG with this bridge in place. If not I will make a small switch to be able to run all three monitors.

Mark1960 · 5th Jun 2023, 7:00 am

I think you meant KITBUG, unless you are switching to 6800.

I was looking at the schematic for the sc/mp kit and introkit and I don’t see why they needed to add the data bus buffer. It’s also odd that it seems it only buffers data from the ROM and RAM to the 8060.

audiokit · 5th Jun 2023, 7:21 am

You are right Mark, i meant Kitbug and I am busy with different systems, switching names every now and then.
It is not sure that it was needed for the Keyboard kit. The edge connector gives you the possibility to add external cards and for that I think they did forsee the buffer.

Phil__G · 5th Jun 2023, 9:55 am

Be sure to use the Kitbug with the terminal bit 7 correction Benny.

audiokit · 6th Jun 2023, 10:57 am

Hello Phil. I allready used that one, I know you did a lot of efford to make this correction. Untill you made the new kitbug version, I always used the 7 bit protocol without issues.

SiriusHardware · 6th Jun 2023, 2:59 pm

Benny, how did you get the numbers and letters on the keys of your keypad? Did the switch tops already come with them printed on?

I have quite a few of those switches and they are very low profile with a nice action, but the keytops on mine are all blank with no legends.

Phil__G · 6th Jun 2023, 3:39 pm

Credit where it is due, it was Michael Haardt who documented the bit7 problem Benny

I was unaware of the cause at the time so my crude fix was a PIC chip in the serial line!

audiokit · 6th Jun 2023, 8:08 pm

Quote:

Originally Posted by SiriusHardware

Benny, how did you get the numbers and letters on the keys of your keypad? Did the switch tops already come with them printed on?

I have quite a few of those switches and they are very low profile with a nice action, but the keytops on mine are all blank with no legends.

I have a lot of them too and indeed most of them had a number printed on. I also had the A, B, C and D but unfortunately not the E and F. So I ordered some 3mm letters which still give me a problem for the Mem, etc keys.
I also found that some of the blank keys had 3 contacts to switch from one to the other.. They perfectly fit in the 2.54mm raster of a standard experiment board or a breadboard. If you need any, just let me know.
Benny

ortek_service · 19th Jul 2023, 1:49 am

Whilst recently at Bletchley Park's TNMoC, I did spot an original IntroKit on display - Maybe one of those previously discussed at the start of this (now closed) thread: https://www.vintage-radio.net/forum/...d.php?t=194874 - In these posts:
https://www.vintage-radio.net/forum/...4&postcount=16
https://www.vintage-radio.net/forum/...9&postcount=17
https://www.vintage-radio.net/forum/...9&postcount=18

This one had a 'SCMPKB-marked' Mask-ROM (/ OT-PROM?) IC.
And I've attached a photo of it (Inc. zipped-up copy, to not get compressed more) here, for reference.

SiriusHardware · 19th Jul 2023, 8:00 am

I'm sure there was an unbuilt Introkit (just the basic serial-comms Introkit, not with the keyboard and display) in a bubble pack near to that one on the occasion of my visit, but that was at least 2-3 years ago now.

Phil__G · 19th Jul 2023, 9:44 am

Thats right, above & left of Owens photo

ortek_service · 20th Jul 2023, 2:05 pm

Thanks for that photo, as well - can't believe I'd missed spotting that / taking a picture of it as well, but I only had a quick look whilst walking past to our Econet room and didn't get chance to go around the whole museum this time, that I'd probably done last time I'd been there for a special event in 2019.
So I'll have to lookout for it, next time I go again, to see if it's still there.

Phil__G · 20th Jul 2023, 6:06 pm

TNMoC is a superb collection but I found the staff sadly disinterested, unlike Cambridge CCH. I politely pointed out a mistake in their Sol-20 description and they werent in the least interested. I offered them some very rare 50+ year-old mags including Byte, Dr Dobbs, Interface Age, Kilobaud, etc but I was ridiculed for offering skip fodder. Really quite disappointed with them. I understand that they have to be selective, thats not the problem - it was the sneering attitude that got me.

ortek_service · 21st Jul 2023, 10:19 am

Maybe you were just unlucky with the 'staff' (all just volunteers?) you met, as the ones we met recently who organised the Econet LAN party, even laying on some free food, and seemed very enthusiastic.
And I've previously been on the tour / attended a valve workshop there- taught / run by colossus chief Engineer etc (who also gave some of the evening talks they used to run, often going to these).

4th Jun 2023, 9:04 pm	#1
audiokit Triode Join Date: Jan 2021 Location: Hulst, Netherlands. Posts: 47	SC/MP introkit + KBkit =MK14 It was some time ago since I posted but this does not mean there was no activity. Some time agon I got the plan to make my second SC/MP kit but now I wanted to add the KBkit. I got myself a Novus 831 calculator just to see if there was anything needed to rebuild it. I did manage to connect the 831 with coloured flatcable to the introkit. Unfortunately some of the keys proved to be unreliable. The calculator did not need any modifications to show the start screen, so the 2 remaing calculator chips were left on the PCB. You also can see that if you watch Curious Marc's youtube video when he lifts the lid of his tin box. So my new plan was to make a reliable keyboard with bubble leds to make it feel a bit like the real calculator. I could see that the MK14 SCIOS-1 is exactly the same as the SC/MP KBkit ROM. To be sure I just programmed the SCIOS-1 bin file on the eprom of my kit and voila, it did run! So Curious Marc should not have typet in all the data to recover his MM5214 ROM. To be sure the SC/MP introkit + KBkit were completely compatible, I loaded the SCIOS-2 and after connecting SENSE-A to ground. it worked just the way my MK14 does. I add some pictures of my build hoping it will stimulate others to build these small single boards as well. Attached Thumbnails

4th Jun 2023, 11:27 pm	#2
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: SC/MP introkit + KBkit =MK14 It's actually quite well known that 'SCMPKB' - the OS for the National Semiconductor Introkit + Keyboard and display - and the original / old OS for the MK14 are one and the same but since the MK14 was only really well known in the UK I would not necessarily expect CuriousMarc to know that, besides which he had a printout of the SCMPKB ROM code right there with the machine so the logical next step in the story was to take that code and type it into a programmer's editor, program a new chip, wire it in in place of the original PROM and see the machine spring to life. It did occur to me a while back that it should be possible to run the 'new' / improved MK14 OS on a National Introkit + keypad and display, but you are the first one to ever try it as far as I know. As it does work, it follows that coolsnaz2's modified version of SCIOS2 with the fast serial loader routine in place of the cassette tape routines should also work in the National Introkit + Keypad + Display.

5th Jun 2023, 12:25 am	#3
Phil__G Octode Join Date: Mar 2011 Location: North Yorkshire, UK. Posts: 1,119	Re: SC/MP introkit + KBkit =MK14 A work of art Benny! very nicely done.

5th Jun 2023, 5:58 am	#4
audiokit Triode Join Date: Jan 2021 Location: Hulst, Netherlands. Posts: 47	Re: SC/MP introkit + KBkit =MK14 Thank you both for the comment and compliment! The next project will be with different boards that are modular all on Eurocard format (as the example I showed) and connected via a backplane. The SC/MP + eprom will then be placed on the main card. At the bottom of this board will be the buffers to improve the fan-out. My intention is to connect the cards I made for the Elektor SC/MP in the intro kit/MK14 computer. It is still possible to run MIKBUG in addition to SCIOS 1 and 2, if the eprom is changed. I have to test if the ROM/RAM connection from the KBd part has to be switched to ground again, that was the only thing I had to change to run SCIOS-1 but I did not try yet to run MIKBUG with this bridge in place. If not I will make a small switch to be able to run all three monitors.

5th Jun 2023, 7:00 am	#5
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,298	Re: SC/MP introkit + KBkit =MK14 I think you meant KITBUG, unless you are switching to 6800. I was looking at the schematic for the sc/mp kit and introkit and I don’t see why they needed to add the data bus buffer. It’s also odd that it seems it only buffers data from the ROM and RAM to the 8060.

5th Jun 2023, 7:21 am	#6
audiokit Triode Join Date: Jan 2021 Location: Hulst, Netherlands. Posts: 47	Re: SC/MP introkit + KBkit =MK14 You are right Mark, i meant Kitbug and I am busy with different systems, switching names every now and then. It is not sure that it was needed for the Keyboard kit. The edge connector gives you the possibility to add external cards and for that I think they did forsee the buffer.

6th Jun 2023, 10:57 am	#8
audiokit Triode Join Date: Jan 2021 Location: Hulst, Netherlands. Posts: 47	Re: SC/MP introkit + KBkit =MK14 Hello Phil. I allready used that one, I know you did a lot of efford to make this correction. Untill you made the new kitbug version, I always used the 7 bit protocol without issues.

6th Jun 2023, 2:59 pm	#9
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: SC/MP introkit + KBkit =MK14 Benny, how did you get the numbers and letters on the keys of your keypad? Did the switch tops already come with them printed on? I have quite a few of those switches and they are very low profile with a nice action, but the keytops on mine are all blank with no legends.

6th Jun 2023, 3:39 pm	#10
Phil__G Octode Join Date: Mar 2011 Location: North Yorkshire, UK. Posts: 1,119	Re: SC/MP introkit + KBkit =MK14 Credit where it is due, it was Michael Haardt who documented the bit7 problem Benny I was unaware of the cause at the time so my crude fix was a PIC chip in the serial line!

19th Jul 2023, 8:00 am	#13
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: SC/MP introkit + KBkit =MK14 I'm sure there was an unbuilt Introkit (just the basic serial-comms Introkit, not with the keyboard and display) in a bubble pack near to that one on the occasion of my visit, but that was at least 2-3 years ago now.

19th Jul 2023, 9:44 am	#14
Phil__G Octode Join Date: Mar 2011 Location: North Yorkshire, UK. Posts: 1,119	Re: SC/MP introkit + KBkit =MK14 Thats right, above & left of Owens photo Attached Thumbnails

20th Jul 2023, 2:05 pm	#15
ortek_service Octode Join Date: May 2018 Location: Northampton, Northamptonshire, UK. Posts: 1,443	Re: SC/MP introkit + KBkit =MK14 Thanks for that photo, as well - can't believe I'd missed spotting that / taking a picture of it as well, but I only had a quick look whilst walking past to our Econet room and didn't get chance to go around the whole museum this time, that I'd probably done last time I'd been there for a special event in 2019. So I'll have to lookout for it, next time I go again, to see if it's still there.

20th Jul 2023, 6:06 pm	#16
Phil__G Octode Join Date: Mar 2011 Location: North Yorkshire, UK. Posts: 1,119	Re: SC/MP introkit + KBkit =MK14 TNMoC is a superb collection but I found the staff sadly disinterested, unlike Cambridge CCH. I politely pointed out a mistake in their Sol-20 description and they werent in the least interested. I offered them some very rare 50+ year-old mags including Byte, Dr Dobbs, Interface Age, Kilobaud, etc but I was ridiculed for offering skip fodder. Really quite disappointed with them. I understand that they have to be selective, thats not the problem - it was the sneering attitude that got me.

21st Jul 2023, 10:19 am	#17
ortek_service Octode Join Date: May 2018 Location: Northampton, Northamptonshire, UK. Posts: 1,443	Re: SC/MP introkit + KBkit =MK14 Maybe you were just unlucky with the 'staff' (all just volunteers?) you met, as the ones we met recently who organised the Econet LAN party, even laying on some free food, and seemed very enthusiastic. And I've previously been on the tour / attended a valve workshop there- taught / run by colossus chief Engineer etc (who also gave some of the evening talks they used to run, often going to these).