UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Computers (https://www.vintage-radio.net/forum/forumdisplay.php?f=16)
-   -   I found it! A very sorry looking MK14. (https://www.vintage-radio.net/forum/showthread.php?t=170727)

circuitryboy 5th Dec 2020 4:24 am

Re: I found it! A very sorry looking MK14.
 
Best I can find for 2111 offers:

https://www.ebay.co.uk/itm/254633994435 (Germany)

SiriusHardware 5th Dec 2020 11:42 am

Re: I found it! A very sorry looking MK14.
 
Circuitryboy, thanks for that very fast and specific response. I've ordered a set of four myself as spares for my two machines, so I'll test them on arrival and give them the thumbs up / thumbs down according to how I find them.

Timbucus 5th Dec 2020 11:47 am

Re: I found it! A very sorry looking MK14.
 
Quote:

Originally Posted by Buzby123 (Post 1317530)
I can get Vicky working with 6561s, and I don't mind that. For Vicky, function is more important than form.

Micky will need 2111s, but I've still got other work to do before I need to fit RAM.

Why am I doing this ?

The 6561's work fine unless you try to use the SOC VDU - but the OrtonView modern VDU should work fine with them.

Good luck on Micky - it will be wonderful to see it fully running.

Because - why have I built so many clones of machines from back then... Because as Sirius says keeping this relatively unknown bit of British computing history alive for the next generation is vital.

SiriusHardware 5th Dec 2020 12:03 pm

Re: I found it! A very sorry looking MK14.
 
Quote:

Originally Posted by Mark1960 (Post 1317512)
Utsource also list the AM27S13/BEA as third part original
.

What exactly does that mean? Obviously any PROMs described as second hand or used / pulled are virtually certain to be programmed already.

Mark1960 6th Dec 2020 12:39 am

Re: I found it! A very sorry looking MK14.
 
Quote:

Originally Posted by SiriusHardware (Post 1317614)
Quote:

Originally Posted by Mark1960 (Post 1317512)
Utsource also list the AM27S13/BEA as third part original
.

What exactly does that mean? Obviously any PROMs described as second hand or used / pulled are virtually certain to be programmed already.

I think third party in this case refers to the various alternate suppliers listed on utsource.

Utsource started including four different categories of components earlier this year. This is the four categories with the additional description :-

Utsource certified original, Original products offered by Utsource. New guaranteed.

Third-party original, Original parts offered by the third-party.

Utsource certified used parts, Used and refurbished parts offered by Utsource are guaranteed can be used normally.

Third-party used parts, Used parts offered by the third-party.

I usually avoid the last two categories.

Third-part original doesn’t specify new, but I have had success with parts in this category, previous orders appear to be unused, so I thought it worth taking a chance on the am27s13bea, also I think these are ceramic. If not blank then I can probably still make some use of them in trying to test a programmer.

SiriusHardware 6th Dec 2020 12:25 pm

Re: I found it! A very sorry looking MK14.
 
Thanks for that clarification, Mark.

Circuitryboy has pointed out that the statement on Cricklewood's website (and therefore in my post #118, where I said the TMS4035NL appears to be equivalent to 2111), is incorrect, that IC is actually a 2102 clone.

The correct TMS equivalent to 2111 is apparently the TMS4042NL. My thanks to the mods for making an appropriate edit to post #118.

Buzby123 7th Dec 2020 5:34 pm

Re: I found it! A very sorry looking MK14.
 
1 Attachment(s)
Vicky is ALIVE !!!!!

With the greatest thanks to Sirius, I can now show my Slothie board running.

And, it gets better ......

My ceramic SC/MP is working !.

Can't do much on it tonight or tomorrow, but I'll use the manual for some bedtime reading. Got to re-learn all the stuff I forgot from 40 years ago.

Cheers,

Buzby

EDIT : That's not a wire link from SC/MP to a 157. The wire is on SC/MP pin 5, but I can't remember why.

Slothie 7th Dec 2020 5:40 pm

Re: I found it! A very sorry looking MK14.
 
Quote:

Originally Posted by Buzby123 (Post 1318423)
Vicky is ALIVE !!!!!

With the greatest thanks to Sirius, I can now show my Slothie board running.

And, it gets better ......

My ceramic SC/MP is working !.

Can't do much on it tonight or tomorrow, but I'll use the manual for some bedtime reading. Got to re-learn all the stuff I forgot from 40 years ago.

Cheers,

Buzby

EDIT : That's not a wire link from SC/MP to a 157. The wire is on SC/MP pin 5, but I can't remember why.

Yay! Thats good news. What was the problem in the end? At least you now have a reference for signals to compare when fixing up Mickey,

Buzby123 7th Dec 2020 5:43 pm

Re: I found it! A very sorry looking MK14.
 
Quote:

Originally Posted by Slothie (Post 1318426)
Yay! Thats good news. What was the problem in the end? At least you now have a reference for signals to compare when fixing up Mickey,

Look back a few posts, ALL my RAMs were duff !.

Timbucus 7th Dec 2020 6:41 pm

Re: I found it! A very sorry looking MK14.
 
Nice Ceramic SC/MP II only ever seen the PMOS V1 in the Gold and Ceramic.

Pin 5 NBREQ is supposed to have a resistor pulling it high to VCC which is R1 / R2 depending on JMP/MKIV - not checked originals or ML

SiriusHardware 7th Dec 2020 6:50 pm

Re: I found it! A very sorry looking MK14.
 
Oh, what a relief. ;) So that's at least four built and working issue VIs we know about now, three among us here, and one elsewhere. Another one here imminent, hopefully.

All of Buz's original 2111s were dud, so he was on a hiding to nothing trying to get either of the machines working with those. Vicky is currently running with 4 * IM6561 RAMs, good job Slothie designed that ability in. He must have wondered, when he did, whether anyone would ever use it.

The supplier for the German-source AM9111s circuitryboy flagged up is telling me to expect them on Wednesday this week which will be pretty quick, if so. I'll test mine the moment they arrive and let everyone know whether they are OK.

Buz, don't forget your manual (Version 1?) describes the operation of the machine with the 'old' OS fitted. There is a .PDF of the V2 MK14 manual on Martin L's site here:-

https://www.8bity.cz/files/MK14/mk14ManualV2_OCR.pdf

..which describes the operation of the machine when the 'New' OS is fitted. It's a nice quality scan but be aware that page 88 - part of the 'Moon Landing' game listing - is missing. Really needs someone with the know-how to reinstate the relevant page from the V1 manual.

Buzby123 7th Dec 2020 7:03 pm

Re: I found it! A very sorry looking MK14.
 
2 Attachment(s)
I've just been in the attic looking for my manual.

Of course, it's not where I expect to find it, so I have to look everywhere else !.

I did find this though. Has anyone else seen what SoC were planning ?

SiriusHardware 7th Dec 2020 7:10 pm

Re: I found it! A very sorry looking MK14.
 
I think Tim had already tracked that information down way back in one of these threads but it's nice to see the original letters, you should keep those safe as part of your MK14 'library'. The general consensus was that the plans for expansion of the MK14 were overtaken by the development of the ZX80, and the rest, as they say, is history.

Timbucus 7th Dec 2020 7:26 pm

Re: I found it! A very sorry looking MK14.
 
https://drive.google.com/file/d/1UvE...ew?usp=sharing

With the missing page added back in.

The Center for Computing History has those letters (Product 73300 and 104831) and it is the basis of my assertion that we need to get as far a NIBL and a proper keyboard on the KB Expansion connector... but, as Sirius says that is a great addition to your collection.

SiriusHardware 7th Dec 2020 7:36 pm

Re: I found it! A very sorry looking MK14.
 
Thanks for doing that - very quick! I don't know if I'm just not patient enough but when I follow your link and try to view it I just get a Whirly Circle Of Doom and the document doesn't appear. Check permissions?

It might be a courtesy to forward the restored version to Martin L so he can put it up on his site as well. I did point out the missing page to him a long time ago but he's a busy man with many interests - however, I'm sure that if he was presented with the 'repaired' version he would be glad to put it up.

Timbucus 7th Dec 2020 7:40 pm

Re: I found it! A very sorry looking MK14.
 
Seems to work OK and is set to anyone on the internet - maybe just replication time to whatever cloud server you are directed to?

Good idea - I will drop him a mail maybe I will mention the OrtonView and ask if his mate is prepared to share the code for the Squash game as well!

SiriusHardware 7th Dec 2020 7:52 pm

Re: I found it! A very sorry looking MK14.
 
Hmm, first time it would not appear at all, second try just now it appeared in seconds. I've got it now, thanks.

We're drifiting into general MK14 territory again now, let's keep this thread mainly focused on Buzby's 'Micky' machine, as and when he is able to make progress on it.

Timbucus 7th Dec 2020 8:15 pm

Re: I found it! A very sorry looking MK14.
 
Yes that is what I am looking forward to as well - as it is such an unusual custom modification - good news on the Replica though as that is a basis for testing in parallel.

Buzby123 8th Dec 2020 2:38 pm

Re: I found it! A very sorry looking MK14.
 
Sad news, Vicky has died !.

Last night I managed to get an hour free, so I swapped back to a plastic SC/MP and typed 'Message' in to Vicky. It worked Jolly Fine.

This morning, powered up again, but was met with a single digit. A few more power attempts gave either a blank screen or a single digit.

Not tried any diagnostics yet, but I suspect the SC/MP. Will try a new one tonight.

As I've said before, the only luck I have is bad luck.

SiriusHardware 8th Dec 2020 3:45 pm

Re: I found it! A very sorry looking MK14.
 
What's the single digit, a reverse 'C' or a '0'?

If '0', would suggest the system is being held in reset.


All times are GMT. The time now is 1:37 am.

Powered by vBulletin®
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.