Karens KO2019 32k scamp running Kitbug++

[SiriusHardware]

And if you do that, seal them in a bag. I've seen too many PCBs being silently destroyed by PCB mounted batteries. You could argue that any battery arrangement put in place by us today will be someone else's problem eventually, not ours - but I always prefer to give things the best chance of survival even if they are now very likely to outlive me.

[ortek_service]

Originally Posted by SiriusHardware

And if you do that, seal them in a bag. I've seen too many PCBs being silently destroyed by PCB mounted batteries. You could argue that any battery arrangement put in place by us today will be someone else's problem eventually, not ours - but I always prefer to give things the best chance of survival even if they are now very likely to outlive me.

A few days ago, I re-discovered some NOS tagged AA NiCd cells I'd got and was quite surprised that there was no sign of any white powder deposits at the ends considering how old these must be (as NiMH ones tended to replace these >20years ago).
However these were maybe quite a late NiCd, as were marked 950mAh (whereas NiCd AA's were typically only 650mAh).

Although these are white-sleeved GP Sylva-Charge 95AAK, rather than more-common Varta (Often Blue (NiCd) / Green (NiMH) with their multi-cell memory-backup batteries)

So I wonder if they more-often leak when in use, after being soldered to a board / when being regularly charged / discharged?
- Although, I recall having some 3.6V NiCd NOS Blue-sleeve RS-branded PCB-Mount batteries, that had leaked white-powder deposits whilst still sealed in original RS bag. So maybe some makes are better sealed and less liable to leak anything corrosive?
Or maybe the smaller, squarer ones are more-likely to leak than the still widely-available single-cell AA type?

And not-sure if the white powder deposit is what actually eats the copper tracks etc, as often you see blueish-colour (like Copper Sulphate, from reaction with copper in leads) corrosion on components some-distance away from the battery.
- So maybe they had actually been outgassing some nasty-chemical gas?


Regarding primary Lithium cells, I thought they often had a 10yr shelf life / expiry date (including use) was 10years from manufacture
- So if they were to last 5yrs when installed, effectively had a shelf-life of 5yrs before using them.
Although I too have too found some dead whilst not been too-far past their expiry date (probably obscure Chinese-brand) ones.
Whereas there were often other makes (probably the better brands like Renata (Swiss Watch etc. batteries company), Maxell, Panasonic etc) that still measured OK and worked quite a while past their official expiry dates.

[SiriusHardware]

Probably a subject worthy of its own thread, but like you I have tended to notice that the metal (IC pins etc) in the area around a decaying PCB mount NiMH battery tends to go acid bluish-green so my feeling is that it's gas / vapour which does the damage and the white stuff is what it becomes when it is deposited on a surface and turns into a solid.

[Phil__G]

Originally Posted by Nick_B333

This looks interesting, I may have to borrow the PIC from my PICL to implement this.

Rapid have PIC16F877-20 chips in stock very cheap at £3.28 each, well worth stocking up for your Karen O sc/mp projects! I just bought 6 for stock...
https://www.rapidonline.com/microchip-pic16f887-i-p-8-bit-microcontroller-8k-flash-73-5188

This is the chip Karen chose for the PIC14 (MK14 clone), the PICL NIBL computer (and V2), and her general SC/MP emulation used here in the 64k KO2019.
A full-house 64k KO2019 running NIBL, KB++, Tookit, FP-NIBL etc (consisting of two chips and an FTDI) can be built for barely over a fiver!
All the fun of a scamp without the expense!

[Buzby123]

[QUOTE=Phil__G;1739952]

Originally Posted by Nick_B333

...

Rapid have PIC16F877-20 chips in stock very cheap at £3.28 each, well worth stocking up for your Karen O sc/mp projects! I just bought 6 for stock...

https://www.rapidonline.com/microchip-pic16f887-i-p-8-bit-microcontroller-8k-flash-73-5188

...

The link is to the 887, not the 877.

Which chip did you mean ?

[Phil__G]

Rats!!! you're absolutely right Buzby, I've ordered the wrong chips & put them away without even looking at them! Sorry chaps. The 887 is physically pin compatible but no doubt the code will need a tweak to sort its clock & stuff.
PIC16F877A'a are available from Rapid but a quid dearer:
https://www.rapidonline.com/microchip-pic16f877a-i-p-8-bit-microcontroller-dip40-73-3352
Whoops!

[SiriusHardware]

One of the things to watch out for on 887 vs 877 is that the 887 port pins which have an analogue-in function --default-- to that operating mode and so you need to switch that off in the configuration part of your code if you need them to be general I/O port pins.

Also when Karen initially decided to use the 887 for Ortonview and then swapped back to the 877 (because she realised she didn't have a programmer for 887) she had to swap two of the ports over, something to do with not all of the ports on one of the two devices being fully TTL compatible.

Slothie ported Karen's code back to the 887 and that code is still attached to a thread somewhere, so it provides a good illustration of the changes needed to make 877 code run on an 887.

[Phil__G]

Yep my 64k KO2019 is now running happily on one of the cheap 887's from Rapid.
This is good cos they're current, and cheaper
So although it was an ordering mistake, I thought these were 877's, its actually turned out ok!

Just a few config changes to the clock, analogues, comparators. I wasnt aware that Ian had done that, I'll see if I can find it but all seems well, its been running 'Life' under KB++ for a while now, runs everything I've tried.
I'll give it a longer soak test then post the code as an 887 version.

I really like the KO2019, a full-house sc/mp system for peanuts
Cheers
Phil

[ortek_service]

I've previously used the PIC16F886's DIL-28 version of the DIL-40 PIC16F887 - Basically same resources, just less GPIO's due to smaller pin-count
But I don't recall using a PIC16F887 yet (Which strangely seem to often be much cheaper than the lower pin-count PIC16F886)

Although whilst these are still in-production, the PIC16F887 has effectively been superseded by the much-more advanced PIC16F18877
(With the PIC16F886 effectively being superseded by the PIC16F18857), which are even-lower cost
(at Farnell, Mouser etc, but RS & Rapid don't seem to stock these) despite their higher spec's.
So if looking for the cheapest IC's, then the PIC16F18877 is maybe worth considering.
However, they are much-less directly backwards-compatible than the PIC16F87 is with the PIC16F877, requiring quite a bit of code-changes.

I do recall getting some PIC16F18877's that were previously an alternative option for the PIC16F877 on those SC/MP using a PIC small SBC's.
However, programming these required a much-more capable PIC / IC-Programmer than the older ones most had.
- Or using Mini-Arduino boards / script to do this, that Phil__G had been doing.

[Phil__G]

Its true the 18877 has more memory and can be clocked faster - though thats not an advantage in this cycle-accurate emulation - but isnt so readily programmed, it involves a particular version of the deservedly-despised MPLABX and its assembler - in fact I'd say its a bit of a mare, whereas the 887 is accommodated by even the old Pickit-2 and MPASM (my goto since MPALC)
Plus I like that because the 887 is pin and 99% register compatible with the 877, its not deviating too far from Karens favourite chip (a unit in one digit!)

I have from time to time pondered a fresh start on something fast, ESP32, STM32N6, or ARM sort of thing, my thinking is that the only instruction that actually needs cycle-accuracy is DLY, everything else can fly flat out, maybe internal memory - imagine an 800Mhz SC/MP!