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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 20th Nov 2019, 6:44 am   #21
circuitryboy
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

We have a couple of new points since my last visit. (These threads go fractal so quickly.)
The one I'm looking at now is possible variations in SCMPKB.
Curiousmarc gives us a crisp reproduction of the NS-supplied teletype listing from the 1976 SCMPKB assembler run. And he's used it to recreate a PROM.
The other sample is from 8bity.cz. (I once sold Martin an '8060N on ebay.) I've trawled through that site and I can only find the SCMPKB listing that's in a full scan of MK14 Manual Edition 1.
This has been retyped and has several 'points of confusion' but the code is the same.
Can you actually display/list the points where your 'modern' EPROM contents diverge?
It is possible that NS used other code versions in their own units. Observe the display in attached.
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Old 20th Nov 2019, 9:58 am   #22
SiriusHardware
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

I think there's an error in Martin's 'Old OS' .obj code.

One byte difference, at 0046 - in paper listings (Old MK14 and SCMPKB) the code at 0046 = CA 08, in Martin's version of the old OS file, the code at 0046/0047 is 08 08.

I still have my 'Old OS' PROMs and if I could find them it would be a simple matter to resolve this, but of course I can not.
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Old 20th Nov 2019, 11:35 am   #23
SiriusHardware
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Also, I did check CuriousMarc's hand-entered version of the SCMPKB code against the listing in the SCMPKB manual - 100% the same, no errors.
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Old 20th Nov 2019, 12:06 pm   #24
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Sorry, something I didn't quite make clear earlier... There is a binary (code) version of the 'Old' MK14 OS on Martin's site although it is quite hard to find - go to the MK14 blog page where he is discussing the existence of two MK14 OSes, and on which there are links to the two versions of the manual. (Assuming you don't read Czech, Let your browser translate the page).

(Unfortunately our IT at work here is so locked down it won't let me go to the site, so I can't post a direct link for you).

Above the links to the manual PDFs there is a line talking about the code which ends in the words ...'be downloaded'. Those two words are a clickable link to downloadable versions of both OS codes, along with the source used to generate them, I believe, although I have not examined the source.

It's that .obj code on Martin's site (the old OS version) which I have found has one byte different (at 0046) compared to the documentation for both the SCMPKB listing and the original MK14 listing, which both agree that the byte at that location should be 'CA', not '08'.
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Old 20th Nov 2019, 12:36 pm   #25
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Lucky that corruption failed-safe to a NOP. And the instruction would be blanking the 9th digit that the NS display doesn't have!
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Old 20th Nov 2019, 1:51 pm   #26
SiriusHardware
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

So, a non-fatal error. That would explain why no-one has tripped over it before now. Maybe someone realised that instruction was redundant and changed it in the source, from which the code was then generated. I assume the original code causes no harm, other than to waste a couple of instructions on an unnecessary act.

I believe you once told me (years ago) that the ninth display could be enabled with the addition of a simple wire, in which case the original instruction presumably would serve a purpose?
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Old 20th Nov 2019, 5:51 pm   #27
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Yes, it's very possible someone masked out the instruction. (I was saying that without that saying that - it only saves 8 micro cycles, but easier than deleting). NS code is klunky: does a 10 count loop for 8 digit display.
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Old 20th Nov 2019, 6:09 pm   #28
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Indeed, so, now that you've neatly solved that mystery for us, how are you getting on with the Tesla-modified PROM burner code? (swerving neatly back on topic).
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Old 20th Nov 2019, 7:50 pm   #29
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Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

OK, just one more post regarding the mysterious change to the byte at 0046 in Martin's version of the Old MK14 OS, it is present and commented on in the .asm file which accompanies the code file.

In case you still did not find that 'MK14 OS Bundle' on the page I mentioned, I have attached it here.
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File Type: zip mk14Monitors.zip (26.4 KB, 26 views)
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