Amstrad PCW RTC

[TynH]

Sounds like great news!

[torrind]

I may finally get what I asked Father Christmas for last year!!  Thanks to Santas lead Elf (Jon). 

[JonB]

I may finally get what I asked Father Christmas for last year!!  Thanks to Santas lead Elf (Jon). 

There's no "may" about it, old boy. It is a dead certainty. And you can take that to the bank!

[JonB]

So, in order to copy the uRTC date/time to the PCW we need to use BDOS function 104, but we first need to convert the date (in BCD) to a 16 bit integer day number with the epoch as 1st Jan 1978. Fortunately the PCW time is stored as BCD. Some fun programming awaits.

[torrind]

......with the epoch as 1st Jan 1978.

Aaaaahhhhh Happy days.... as a 10 year old in flares, long hair and my trustee Steed "Grifter"




Darren

[TynH]

So, in order to copy the uRTC date/time to the PCW we need to use BDOS function 104, but we first need to convert the date (in BCD) to a 16 bit integer day number with the epoch as 1st Jan 1978.

Is that a typo or am I missing something? Pretty sure my non-RTC equipped machines all revert to 01/01/1970 unix time. AFAIK only AmigaOS used 1978.


Edit: well a quick google proved me wrong and CP/M indeed used Jan 1978 - Sept 2067.
My bad.

[JonB]

 @TynH Yes it's a bit odd. But my info comes from the hallowed book "The Amstrad CP/M Plus" by David powys-Lybbe and Andrew RM Clarke. In it, they show how to convert the day number to a date (in assembler) but not the other way round. Looks like I'll have to do some real work this time! Unless @JohnElliott comes to my rescue!

[JonB]

Quick demo of uRTC on the Superbrain.


https://www.youtube.com/watch?v=POBRlgAFxmo

[torrind]

Excellent work Jon.


Not too familiar with the Superbrain but What a wonderful old machine.... hmmmm maybe I need to investigate one for myself !


*edit: Hmmmm looking at the price of one on eBay, probably not!!


Darren

[JonB]

Darren, they are proper CP/M boxes, now supported fully by uIDE and uRTC. A good working one should be about £250 (if you can find one - the eBay item is grossly overpriced). There are not enough (active) SB owners in the UK. Or anywhere to be fair. So let me know if you score one and we will nurse it back to health and get you in touch with the few other owners.

It's all a bit odd. The SB sold in huge numbers due to its robust all-in-one nature and quality keyboard. A genuine business workhorse. Yet so few remain, seemingly.

[torrind]

Thanks Jon.


There is one currently on ebay for £500 so I'll give that one a miss! I'll keep my eyes peeled for others! Thanks for the offer of support should it be needed!


Darren

[JonB]

So, back on topic (although I do love chatting about Superbrains), I spent the day working on the software and have "sort of" got the Superbrain uRTC.COM utility modified so as to build the CP/M Plus date time buffer and feed it to the BIOS to transfer the uRTC time to the PCW operating system. I say "sort of" because I cannot transfer the program to a PCW at the moment because my CPS8256 serial interface seems to have packed in. As a result, I am forced to debug it on the Superbrain. Not ideal.

But it is progress of sorts...

[JonB]

Right, got bored today and took out the 'scope to look at the CPS8256. Turned out the MC1489 receiver chip was toast and I luckily had a spare. Swapped them out and I have a working Kermit transfer again.

A quick rebuild of uRTC.COM (with the BDOS call to set the time uncommented out) and it appears to be working. You need the Y2K compliant versions of DATE.COM, SHOW.COM and DIR.COM as well as uRTC.COM to operate the full system, but I need to do some more testing before releasing it.

Please form an orderly queue...

[Edit: Predictably enough, I have already found a bug!]

[torrind]

#1


me




(need to check I have the Y2K compliant versions of the .com commands tho')


Darren

[JonB]

Darren, you can download them from Gaby.de.

Bug is fixed but more testing to do. Watch this space.

[TynH]

#2 

[torrind]

Hi Folks,


Firstly, Merry Christmas - Hope you all get everything you want....


What I'd like Father Christmas to bring me is a RTC addon for my PCW8256 - I've found instructions to build one in German, but this isn't much good to me.

So I've been running with uRTC all week and time stamping like crazy!!!!


For those of you that remember, Last December 25th I posted a request for a pressie from Father Christmas and 10 months later I have it!!


Just want to put it out there of my next Christmas pressie! but being the sad git I am, I'll post it on Dec 25th 2019. 




I hope that doesn't worry anyone (Jon in particular )




Darren
uIDE, uRTC BBC

[TynH]

Unfortunately I can't get mine to do anything apart from locking up the machine, necessitating a power cycle.

[torrind]

Hmmm


Thats not good!


I had issues initially and these were down to a dodgy IDE cable.


If its locking up your machine then its obviously detecting something it doesn't like. Unfortunately I'll not be much help and would have to defer to Jon.


Darren

[TynH]

Certainly feels like a pretty solid crimp but how to tell? 

[JonB]

Check these first

http://www.cpcwiki.eu/forum/nc100-nc200-pcw-pda600/announce-urtc-8-universal-rtc-for-the-pcw-and-other-z-80-computers/msg179222/#msg179222

[TynH]

@torrind did you manage to find a ready-made cable with all three sockets?


"Ultimately it may be down to bad cable crimping by me, so I have ordered a ready-made cable from Ebay which should arrive in the next few days."
Could you tell me where you got yours from? I had to add a third connector myself.

[TynH]

Check these first

http://www.cpcwiki.eu/forum/nc100-nc200-pcw-pda600/announce-urtc-8-universal-rtc-for-the-pcw-and-other-z-80-computers/msg179222/#msg179222

Before removing the battery:

https://i.postimg.cc/4Jqcq1B9/4456-A847-1-C76-4-EB1-8913-33-FFAB8-B460-E.jpg?dl=1


https://i.postimg.cc/MzrffDkF/14-EA4545-9611-498-B-8-AFF-3561-F74-E7436.jpg?dl=1

After battery removal. Still hangs:


https://i.postimg.cc/VYrrqCmL/61-B9-E2-B1-D620-4-F7-A-8918-444-FF5615611.jpg?dl=1


edit posting pictures not working?

[torrind]

This is exactly what was happening to me.


I fixed it by buying a ready-made cable from eBay which fixed the issue.
https://www.ebay.co.uk/itm/40-Way-IDE-UDMA-ATA-HDD-CD-DVD-Ribbon-Cable-Data-Splitter-MBA017B/390492423530?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649


Darren

[TynH]

Thanks apparently I wasn't searching for the correct thing, lots of offers now.
Ordered one but it's probably going to take a while, won't be able to test until next month or so.