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General comments and SC/MP [message #7070] Sun, 09 February 2020 08:57 Go to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
I've only just joined this forum and I am already struck by the very high standard of work being done by the members of this forum.

I'm a stick in the mud and I've resisted new stuff, but look at what has been accomplished using FPGAs!

Amazing.

I just want to ask if there are any SC/MP enthusiasts out there? I ask because this under-powered microprocessor has a special place in my heart. It was the first micro I learned to code for, and I spent many an hour at uni finding the Dr Dobb's article on National's Industrial Basic Language (NIBL) and then entering the hex into an ancient Burroughs computer to blow four 2708s.

I'm still living in 1979 and Martha and the Muffins are on the radio Smile

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Re: General comments and SC/MP [message #7071 is a reply to message #7070] Sun, 09 February 2020 12:01 Go to previous messageGo to next message
kman is currently offline  kman
Messages: 45
Registered: February 2019
Location: Germany
Member
Hi,
I've started with a SC/MP-I system (LED-Display and hex-keyboard) in 1978 too. At present I do not have anything from these ancient days any more. So, what are your intensions to do with this cpu ?


Cheers
Kurt

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Re: General comments and SC/MP [message #7072 is a reply to message #7071] Sun, 09 February 2020 13:17 Go to previous messageGo to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
Hello Kurt,

I wanted to get back into the SC/MP about 13 years ago. I looked around on Ebay for a second hand Mk14 (a popular SC/MP kit here in the UK) but I was shocked at the prices. Even a bare SC/MP IC seemed ludicrously expensive. So I wrote a cycle-perfect emulation of an SC/MP on a PIC microcontroller, and made myself an Mk14 (or at least something very close to it Smile

My latest machine has a 20MHz PIC16F877-20/P emulating a 4MHz SC/MP. I've got NIBL in EPROM and 24k bytes of SRAM (a 62256). The emulation includes all processor flags.

For a while I thought about making the machine from late-70s parts but decided that'd be expensive. I'd need a rack chassis! 24k bytes of SRAM was multiple cards back then!

My main motivation for making this NIBL machine (I've already built several) was to add some support routines in ROM, including an assembler, which I've been developing these past weeks.

I just wondered if there'd be any interest in this machine...?

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Re: General comments and SC/MP [message #7076 is a reply to message #7072] Mon, 10 February 2020 15:33 Go to previous messageGo to next message
djmartins is currently offline  djmartins
Messages: 40
Registered: February 2018
Member
I have no doubt there will be people interested in the machine and how you did it all.
They sold a lot of those boards back then so surely at least a few people want to reminisce like you.
We live in golden times indeed where you can emulate machines that costs tens of thousands with $5 boards.
I was just messing with PCjs, a javascript emulation of a PC and other machines that runs on most web browsers
but I am not sure it will run on Netscape Navigator!
Here is a link to that, while off topic, some here might enjoy:
https://www.pcjs.org/
if not mods can edit my post.....

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Re: General comments and SC/MP [message #7080 is a reply to message #7072] Mon, 10 February 2020 20:10 Go to previous messageGo to next message
kman is currently offline  kman
Messages: 45
Registered: February 2019
Location: Germany
Member
Hi,
to simulate a SC/MP with a PIC is amazing. I've searched ebay and was astonaged about the unrealistic pricing for 1 chip. The cheepest offer was $15,-- (China) the most expensive €95,-- (GB). I gave China a try for 1 chip - that is feasable. Regarding the assembler, there is already one for PC that can do the job: AS-1.45. This piece of software knows a lot of cpu's. SC/MP-I/II & -III amongst all the others. There is a web site that hold some information about NIBL and others. For me it should be possible to build a SC/MP-system using my multicomp board. Needed is only a small pcb carrying the cpu and some level-convertes to connect it to the FPGA - as you already said: golden times... Seeing NIBL running again (at 1200Bd), fascinating !

Regarding the PCjs web-site: fascinating. Even the speed of these old hardware seams to be simulated. From nowadays point of view I do not understand how it was possible to work on these boxes: they boot..and..boot..and...

cheers
kurt

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Re: General comments and SC/MP [message #7081 is a reply to message #7080] Tue, 11 February 2020 05:50 Go to previous messageGo to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
Okay, I'll post details just as soon as I've tested the code I've written.

I've used the AS assembler of Alfred Arnold and team for SC/MP code development many times. It's a brilliant concept (versatile multi-processor support).

A 20MHz PIC emulating a 4MHz SC/MP sounds like an accomplishment - until you realise there's something like a 50 fold difference in MIPs (5 compared to about 0.1). So it's not really so amazing! The 'add extension' ADE instruction proved the most critical!

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Re: General comments and SC/MP [message #7084 is a reply to message #7081] Tue, 11 February 2020 08:24 Go to previous messageGo to next message
gkaufman is currently offline  gkaufman
Messages: 186
Registered: October 2015
Senior Member
I'm also interest in hearing more about your SC/MP project.

I'd love to see the original circuit board re-created, as I have a few INS8060's lying around...

- Gary

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Re: General comments and SC/MP [message #7085 is a reply to message #7084] Tue, 11 February 2020 08:40 Go to previous messageGo to next message
djmartins is currently offline  djmartins
Messages: 40
Registered: February 2018
Member
https://sites.google.com/site/gogleoops/home/sc-mp-ii-max

^^^^^^^^^^^^^^^^^^^
Not original but takes your chips...

https://www.pcbway.com/project/shareproject/Miniscamp_II_mai n_PCB.html

[Updated on: Tue, 11 February 2020 08:46]

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Re: General comments and SC/MP [message #7086 is a reply to message #7085] Tue, 11 February 2020 09:49 Go to previous messageGo to next message
kman is currently offline  kman
Messages: 45
Registered: February 2019
Location: Germany
Member
attached the original Elektor design: SC/MP-II CPU-Board w. NIBL-Interpreter

cheers
Kurt

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Re: General comments and SC/MP [message #7087 is a reply to message #7086] Tue, 11 February 2020 11:16 Go to previous messageGo to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
Originally, NIBL ran in page 0 (0x0000-0x0fff) but Elektor was already using this page for their monitor (Elbug...?Wink. They had to relocate NIBL to page 1 (0x1000-0x1fff), which I expect kept someone up late at night Smile

Well, I've got my new code running in the hardware today (previously running in a PC emulation). Things never go smoothly, do they? Working now though - I succeeded in saving a two line program to cassette and reloading it to another page. I'll try out the assembler tomorrow.

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Re: General comments and SC/MP [message #7097 is a reply to message #7070] Fri, 14 February 2020 15:38 Go to previous messageGo to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
Here's the write-up and source files for my NIBL computer.

I wish I'd thought to do this forty years ago!

[Updated on: Fri, 14 February 2020 15:59]

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Re: General comments and SC/MP [message #7098 is a reply to message #7070] Fri, 14 February 2020 15:41 Go to previous messageGo to next message
kareno is currently offline  kareno
Messages: 19
Registered: October 2019
Junior Member
...and of course you'll need a sticker to advertise the processor it's using!

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Re: General comments and SC/MP [message #7099 is a reply to message #7098] Fri, 14 February 2020 16:18 Go to previous messageGo to next message
djmartins is currently offline  djmartins
Messages: 40
Registered: February 2018
Member
Perfect sticker!

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Re: General comments and SC/MP [message #7100 is a reply to message #7085] Sun, 16 February 2020 18:01 Go to previous messageGo to next message
gkaufman is currently offline  gkaufman
Messages: 186
Registered: October 2015
Senior Member
I've built up the first board - it works reasonably well, but the use of a Dallas memory backup/ram isn't my favorite approach. I would have preferred a more standard Eprom/Ram.

- Gary

djmartins wrote on Tue, 11 February 2020 08:40
https://sites.google.com/site/gogleoops/home/sc-mp-ii-max

^^^^^^^^^^^^^^^^^^^
Not original but takes your chips...

https://www.pcbway.com/project/shareproject/Miniscamp_II_mai n_PCB.html

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Re: General comments and SC/MP [message #10846 is a reply to message #7100] Thu, 12 September 2024 15:29 Go to previous message
phil_g is currently offline  phil_g
Messages: 31
Registered: November 2020
Member
Bumping this thread as a lot has happened on the SC/MP front since 2019. Sadly Karen is no longer with us, but I took
a particular interest in her designs and continued development & bugfixes. There are design updates to the PICL, PIC14,
and Karens 2019 design mentioned above which I've called the KO2019. We also have full-house SC/MP systems with the
KitbugPlus monitor, NIBL-E, PAGE3.SYS, NIBL-FP and the NIBL-E Toolkit. If you're interested in the SC/MP or Karens PIC
emulations please take a look at https://philg.uk on the SC/MP and the PIC-emulated SC/MP pages.

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