RE: Source code CBM 8032

From: Baltissen, GJPAA (Ruud) <ruud.baltissen_at_apg.nl>
Date: Fri, 13 Oct 2017 07:02:32 +0000
Message-ID: <54F350D2C6501448A3EE14B7854C5FB563EE8808@WSV10441N3.office01.internalcorp.net>
Hallo Spiro,


> After GetVariable:
> ...it only checks if the pointer is below $8B00.

That was clear indeed. But it doesn't make any sense, at least to me. As Olaf thinks of this as well, I comment it as
	cpx	#$8B			; smaller than ?   probably bug, should
					; have been $8000 IMHO

> A_DDA8/A_DDAF:
>        Isn't $91 the token for ON (not TO is stated on A_DDA8)?
>        And $A4 is the tken for TO.

You are absolutely right. Plain error from my site.


> Could this check by a "poor man's" check for EOI?

Having no idea at all, I added the above as comment.


> A_E408: Most probably, a delay in the scroll like pressing ...

Aha, that makes sense! Regarding the key, IMHO it is the "Reverse on" key. Why? PIA1RegA is only set at a few points.
- It is set to $xF after a reset and this piece of code is not accessed by any other code.
- It is set to $x0 during the start of the interrupt routine (look for "A_E47a:")
- It is incremented after "A_E4F9" but only after register X has been checked. X was set to $50 = 80 keys just before "A_E4CD". So IMHO PIA1RegA = $x9 the moment X becomes zero and will stay so until the next IRQ.
- The mask $FE represents the "Reverse on" key IMHO. Look for the table under "TblKeyboard:" in my source.


> SendByteIEEE: ...

Got it!


> Between bcCLOSE4 and A_F315: .... an "end of tape" marker ...

Got it!


> TblDay: 24 h + 1/60,

Got it!


> A_F818 to A_F828: If the secondary address ...

Got it!

Herzlichen Dank!


If anyone disagrees with the result, we always can discuss matters here :)


Met vriendelijke groet / With kind regards, Ruud Baltissen

www.Baltissen.org






De informatie in dit e-mailbericht is vertrouwelijk en uitsluitend bestemd voor de 
geadresseerde. Wanneer u dit bericht per abuis ontvangt, verzoeken wij u contact op te 
nemen met de afzender per kerende e-mail. Verder verzoeken wij u in dat geval dit 
e-mailbericht te vernietigen en de inhoud ervan aan niemand openbaar te maken. 
Wij aanvaarden geen aansprakelijkheid voor onjuiste, onvolledige dan wel ontijdige 
overbrenging van de inhoud van een verzonden e-mailbericht, noch voor daarbij 
overgebrachte virussen.

APG Groep N.V. is gevestigd te Heerlen en is ingeschreven in het 
handelsregister van de Kamer van Koophandel Limburg onder nummer 14099617


The information contained in this e-mail is confidential and may be privileged. 
It may be read, copied and used only by the intended recipient. 
If you have received it in error, please contact the sender immediately by 
return e-mail; please delete in this case the e-mail and do not disclose its 
contents to any person. We don't accept liability for any errors, omissions, 
delays of receipt or viruses in the contents of this message which arise as a 
result of e-mail transmission.

APG Groep N.V. is registered in the trade register of the Chamber 
of Commerce Limburg, The Netherlands, registration number: 14099617


       Message was sent through the cbm-hackers mailing list
Received on 2017-10-13 08:00:02

Archive generated by hypermail 2.2.0.