22nd Jun 2020, 12:56 pm | #41 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
Posts: 1,287
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Re: SC/MP timing and microcode information
I bought a set of five SC/MP 2 chips from china that were only marked with "INS8060" and a datestamp in the early 80s so looks may not be a reliable indicator. 4 of the 5 chips i received worked fine in my MK14 with only 1 doa. I didnt pay much for them. Looking at the legs of the chips I would imagine they are equipment pulls because they seem to have traces of solder on the legs - perhaps they were some kind of second source rather than original NS chips.
I bought one from a seller in Spain which wad nicely marked and works and is rhe one currently in my 1.0 prototype, and it is a 1980 chip i think so if its early chip you should look for the white vertical bar, and Isp8a-600 ins8060 markings with a NS logo as per attached stock photo. |
22nd Jun 2020, 1:37 pm | #42 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
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Re: SC/MP timing and microcode information
Thanks for that. There seems to be a variety of different t silk screen colours and fonts about. Ours good to have something to compare against especially as I'll be starting from scratch!
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22nd Jun 2020, 2:46 pm | #43 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
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Re: SC/MP timing and microcode information
Mm, I'm struggling to find any with the white line inside the pips and the same font.
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22nd Jun 2020, 7:05 pm | #44 | |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
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Re: SC/MP timing and microcode information
Quote:
The second is one I harvested from the wreckage of a late seventies EPROM programmer along with an 8154, now running in an MK14 replica. Both are marked very similarly and, I have never noticed this before, neither has the Nat Semi trademark vertical white stripe which even I expected that they would have. I notice the printing on them is quite shoddy as well, with the lettering on the second device sliding gradually downhill. The lack of a white stripe and the general clunkiness of the lettering might well have led me to conclude they were fakes if I was looking to buy them now but I assure you both of the ICs in these images are genuine, roughly 40+ years old and both work. |
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22nd Jun 2020, 8:11 pm | #45 |
Octode
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
Posts: 1,298
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Re: SC/MP timing and microcode information
Bad quality printing might be a good sign, also there is no guarantee that the picture they use is the part they will ship. Better to check the feedback for that supplier.
It may also be worth checking Utsource, though it seems they only have second user parts now, but at least they advertise that fact and say they can be reurned if not satisfied, though I haven't tried returning anything yet which is probably a good sign. I didn't order INS8060 from them yet. Attached from my MK14, with the INS8060 that was fitted when I bought it from classified adds in I think early 80s. |
22nd Jun 2020, 8:16 pm | #46 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: SC/MP timing and microcode information
Here are mine. I realised I had never taken the NOS one in a tube out or tested it so I did so... and it works... These are from a variety of sources - one is just a random Chinese seller on e-bay (the one where the printing seems to have worn off) I took a chance on a year or so ago. Two are from utsource bought in separate orders and the NOS one in original tube is from a UK supplier. The one in the SCRUMPI is from my JMP MK14 so the first one I bought from uTsource
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22nd Jun 2020, 8:22 pm | #47 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: SC/MP timing and microcode information
It is documented that there were never any second source suppliers although they were made all over the place according to my NOS tube - so it is likely variations in plant marking?
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22nd Jun 2020, 8:23 pm | #48 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
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Re: SC/MP timing and microcode information
Thanks all, very helpful. There looks to be a fair variety there. I'll have a punt later they all seem fairly expensive though my primary concern is spending ages trying to get a dead part to work .
D |
22nd Jun 2020, 8:38 pm | #49 |
Octode
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Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: SC/MP timing and microcode information
tv.links who I got the NOS one off are still selling them and not to bad considering you do not have to worry about order value and import fees which are significant. They even throw in a photocopy of the reference card - they only had a few with originals...
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23rd Jun 2020, 10:08 am | #50 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
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Re: SC/MP timing and microcode information
Thanks, I ordered one from there last night so hopefully it will be a good 'un. Now to dive in and start breadboarding!
I'll probably just make something dead simple with just a ROM and small RAM to start off with. I'm not sure about how to test but I was thinking of putting the ROM low in page 0 and then some RAM in pages 1,2 - would that be enough to get something like NIBL basic running and then just use the serial in/out pins straight to either a BBC micro's RS423 port or to a PC/USB via a max232 type chip? I've seen this circuit https://www.dos4ever.com/SCMP/SCMP.html#NIBL but that seems to have the teletype interface going to the sense/flags registers? I've not delved into the NIBL Basic code yet - do I need to do anything special to get it to run or should it "just work" if I get the ROM/RAM layout working - and use the right pins for serial Thanks again for the pointers D |
23rd Jun 2020, 10:28 am | #51 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
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Re: SC/MP timing and microcode information
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23rd Jun 2020, 11:17 am | #52 | |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
Posts: 1,287
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Re: SC/MP timing and microcode information
Quote:
The NIBL source is around if you look for it the most common being the Elektor NIBL-E which is modified to sit in page 1 as the Elektor machine had a monitor ROM in page 0. I can't find the link at the moment but if I do I'll post it here. I'm looking into making a NIBL adaptor for the MK14 and I'll probably use that layout with 24k ram on a daughter board plugged into the SC/MP socket (I think I read somewhere that NIBL can't address higher than 32k) |
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23rd Jun 2020, 4:08 pm | #53 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
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Re: SC/MP timing and microcode information
Thanks Sirius, if I get stuck I may take you up on that!
Thanks Slothie, I'll keep digging tonight into NIBL...it will probably be a while until I'm that far advanced...so far only LDI,LD and ST working on my cpld! I realised that I'd misunderstood the timing (that a microinstruction takes two XIN/XOUT cycles) but hopefully that should be easy enough to put right but I'd really like to see a real chip in action before I go a lot further. D |
23rd Jun 2020, 4:59 pm | #54 |
Octode
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
Posts: 1,298
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Re: SC/MP timing and microcode information
Try the introkit firmware first. Curiousmarc.com has the manual with schematic and software. Uses sense input and flag output for serial interface and should be easy to connect to an ft232 type adapter.
Note the serial output needs an inverter. |
23rd Jun 2020, 5:59 pm | #55 |
Dekatron
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Location: Newcastle, Tyne and Wear, UK.
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Re: SC/MP timing and microcode information
The first post in this now closed thread contains a link to CuriousMarc's SC/MP information stash. You could do worse than build an 'Introkit', but bear in mind that the Introkit used an SC/MP I with all the power supply weirdness that implies so you'd have to 'convert' it to SC/MP II. I think one of the documents in the stash explains how to do just that.
https://www.vintage-radio.net/forum/...d.php?t=159537 |
23rd Jun 2020, 6:06 pm | #56 | |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
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Re: SC/MP timing and microcode information
Quote:
https://www.curiousmarc.com/computin...microprocessor |
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23rd Jun 2020, 6:10 pm | #57 |
Dekatron
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Re: SC/MP timing and microcode information
Oops, should have checked it, sorry. Thanks for the redirection.
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23rd Jun 2020, 6:28 pm | #58 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
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Re: SC/MP timing and microcode information
Now I wanted to build an introkit! Not much point as it's basically the same as the MK14 I've already built but.......
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23rd Jun 2020, 8:43 pm | #59 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: SC/MP timing and microcode information
I have been planning a NIBL job for a while but, like Slothie I want to do it for my MK14 really!
This may interest you: http://adeldor.com/SCMP_II_NIBL_MCU.html The article on a simple NIBL computer is in May 1979 Elektor: https://worldradiohistory.com/UK/Ele...or-1979-05.pdf |
23rd Jun 2020, 8:44 pm | #60 |
Rest in Peace
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Re: SC/MP timing and microcode information
I can shed some light on NIBL's use of processor flags for serial I/O.
F0 is the serial going TO the terminal. It is inverted for a TTL serial signal, so you'll need an inverter or transistor to connect it to an FTDI lead or MAX232 chip. SB is serial FROM the terminal and is of normal polarity. What is less understood is F1, which is a hardware flow control signal. NIBL raises this flag to turn on a 'reader relay' which starts the transmission of a character from the terminal's paper tape reader. As soon as a character begins to come in, NIBL lowers F1 to prevent further transmission. Most people ignore F1 and use end-of-character and end-of-line delays for flow control, but I have successfully used F1 to drive RTS (request to send). Trouble is, too many serial ports cannot throttle their serial sender to character resolution. Those USB/serial adapters are notorious, some not implementing hardware flow control at all! Hope this helps. |