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Sandbox ROM vs Childish Prank
Message #1 Posted by Howard Owen on 28 Jan 2012, 3:35 p.m.

On the HP41 Facebook group, a member posted the ol' SF 11 turn off trick. I recalled another prank along the same lines:


01 SF 11
02 OFF
03 'MEMORY LOST
04 AVIEW

I keyed this into my HP41CL and it failed, much to my surprise. It turns out the Sandbox ROM startup banner interferes with the AVIEW somehow. I tried it on i41CX and had the same result with the Sandbox ROM installed. Taking it out made it run like I expected.

I don't think Ángel should worry. Given what I'm trying to do here, it's hard to call this a bug. :)

      
Re: Sandbox ROM vs Childish Prank
Message #2 Posted by Ángel Martin on 29 Jan 2012, 3:03 a.m.,
in response to message #1 by Howard Owen

Howard, you must be the only SandBox user left in the world ! Sorry it ruined your prank demo :-)

Yes its greetings banner does not yield to the other modules plugged after it, as back then (2002 if memory serves) I knew little about other ways to implement that. The name "SandBox" says it all..

I can of course change this now but it's hardly worth the effort. All other modules after it (SandMATH, 41Z, TOOLBOX, etc, etc) use "approved" calls that hand the execution back on to the OS after the code in the polling points is done - creating buffers, assigning keys, etc.

Best example is the SECURE functions in the CL_Utils module, which allows for user prompts *during* that phase, and yet it returns happily to the OS - assuming the right password is entered.

Best, 'AM

            
Re: Sandbox ROM vs Childish Prank
Message #3 Posted by Massimo Gnerucci (Italy) on 29 Jan 2012, 5:55 a.m.,
in response to message #2 by Ángel Martin

Quote:
Howard, you must be the only SandBox user left in the world !

Ángel, Howard is not alone! ;)
I have it burnt into Clonix, and a couple of instances of V41, if memory serves... fond memories, maybe. Thanks for it, of course.
Massimo

                  
Re: Sandbox ROM vs Childish Prank
Message #4 Posted by Ángel Martin on 29 Jan 2012, 6:16 a.m.,
in response to message #3 by Massimo Gnerucci (Italy)

ok, so ¨by popular demand¨ (hey two users and counting!!! :)) I´ll redo the splash code on the SandBox... give me a few days while I dig out the archaeological construct.. should be fun to confront myself with the early sins of my MCODE days - definitely more benign than today´s!

Edited: 29 Jan 2012, 6:16 a.m.

                        
Re: Sandbox ROM vs Childish Prank
Message #5 Posted by Massimo Gnerucci (Italy) on 29 Jan 2012, 8:04 a.m.,
in response to message #4 by Ángel Martin

Quote:
ok, so ¨by popular demand¨ (hey two users and counting!!! :))

Ahahah... :D
Thank you if you want to venture in this! Actually mine was not a change request but an endorsement! ;)

Greetings,
Massimo

Edited: 29 Jan 2012, 8:05 a.m.

                              
Re: Sandbox ROM vs Childish Prank
Message #6 Posted by Ángel Martin on 29 Jan 2012, 4:04 p.m.,
in response to message #5 by Massimo Gnerucci (Italy)

Well well, it looks like the the needed changes weren´t that difficult - see below for the required patch, involving just patching 5 bytes at address pFE0 to pFE4:

BFE0	320	DSPTOG	display ON
BFE1	391	PORT DEP:	
BFE2	08C	XQ	
BFE3	3DB	->BBDB	[WAIT&SEE]
BFE4	320	DSPTOG	display OFF

Since it uses HalfNut lower case characters it won´t be very descriptive on the CL, specially if you have it in TURBO50 startup.

Best, ÁM.

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