LISTINGS!

Discuss the reverse engineering and emulation (as opposed to simulation) of any sort of Prevue hardware, including Atari-based and Amiga-based EPG channels and the Amiga-based Prevue/TV Guide channels.
AriX
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Re: LISTINGS!

Post by AriX »

Talked to the guy from United Video today... He said that at one point or another, the EPG Jr. software may have had a crawl at the bottom of the screen that went through ads or maybe strings that were sent over serial, and was activated through a configuration command. He's not sure if the version we had was like that or not, but it may have been. He also said that some version of the Atari software had a code download feature that allowed it to overwrite its own EEPROMs, although this was not actually used much.
tin
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Re: LISTINGS!

Post by tin »

AriX wrote:Talked to the guy from United Video today... He said that at one point or another, the EPG Jr. software may have had a crawl at the bottom of the screen that went through ads or maybe strings that were sent over serial, and was activated through a configuration command. He's not sure if the version we had was like that or not, but it may have been. He also said that some version of the Atari software had a code download feature that allowed it to overwrite its own EEPROMs, although this was not actually used much.
I'm pretty certain there's nothing in our version of the Atari code that could do a bottom of the screen crawl. I can see that you can send ads and make them scroll or crawl, but there's no code that I can see that would do the appropriate stuff to the screen.
AriX
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Re: LISTINGS!

Post by AriX »

tin wrote:
AriX wrote:Talked to the guy from United Video today... He said that at one point or another, the EPG Jr. software may have had a crawl at the bottom of the screen that went through ads or maybe strings that were sent over serial, and was activated through a configuration command. He's not sure if the version we had was like that or not, but it may have been. He also said that some version of the Atari software had a code download feature that allowed it to overwrite its own EEPROMs, although this was not actually used much.
I'm pretty certain there's nothing in our version of the Atari code that could do a bottom of the screen crawl. I can see that you can send ads and make them scroll or crawl, but there's no code that I can see that would do the appropriate stuff to the screen.
Okay, fair enough. Must have been a different version. What do you mean by getting ads to crawl though?
tin
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Re: LISTINGS!

Post by tin »

AriX wrote:Okay, fair enough. Must have been a different version. What do you mean by getting ads to crawl though?
The ads have some property that defines them as a crawl (scroll across the bottom of the screen) or scroll (in line with the channel information). Obviously this doesn't work in Grid, and possibly List either. In http://www.youtube.com/watch?v=190dS5kmlPA you can see the crawl ads being redefined live by the local operator.

I'm not sure how either works over the air - possibly via a command. I must admit looking at the Atari code that I think it would be quite hard (too processor intensive) to get a scroll across the bottom of the screen, as the state of each character would have to be re-defined by the processor every frame - like it does when the timestamp scrolls into the top bar. The Atari hardware seems to support the vertical scrolling very well due to its display lists, but not any kind of horizontal scroll - especially when there is vertical scrolling also going on.

I could of course be quite wrong about that, I am no atari hardware expert!
AriX
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Re: LISTINGS!

Post by AriX »

tin wrote:
AriX wrote:Okay, fair enough. Must have been a different version. What do you mean by getting ads to crawl though?
The ads have some property that defines them as a crawl (scroll across the bottom of the screen) or scroll (in line with the channel information). Obviously this doesn't work in Grid, and possibly List either. In http://www.youtube.com/watch?v=190dS5kmlPA you can see the crawl ads being redefined live by the local operator.

I'm not sure how either works over the air - possibly via a command. I must admit looking at the Atari code that I think it would be quite hard (too processor intensive) to get a scroll across the bottom of the screen, as the state of each character would have to be re-defined by the processor every frame - like it does when the timestamp scrolls into the top bar. The Atari hardware seems to support the vertical scrolling very well due to its display lists, but not any kind of horizontal scroll - especially when there is vertical scrolling also going on.

I could of course be quite wrong about that, I am no atari hardware expert!
Ah, right, forgot about that video. Interesting thoughts though.
swest77
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Re: LISTINGS!

Post by swest77 »

AriX wrote:
tin wrote:
AriX wrote:Okay, fair enough. Must have been a different version. What do you mean by getting ads to crawl though?
The ads have some property that defines them as a crawl (scroll across the bottom of the screen) or scroll (in line with the channel information). Obviously this doesn't work in Grid, and possibly List either. In http://www.youtube.com/watch?v=190dS5kmlPA you can see the crawl ads being redefined live by the local operator.

I'm not sure how either works over the air - possibly via a command. I must admit looking at the Atari code that I think it would be quite hard (too processor intensive) to get a scroll across the bottom of the screen, as the state of each character would have to be re-defined by the processor every frame - like it does when the timestamp scrolls into the top bar. The Atari hardware seems to support the vertical scrolling very well due to its display lists, but not any kind of horizontal scroll - especially when there is vertical scrolling also going on.

I could of course be quite wrong about that, I am no atari hardware expert!
Ah, right, forgot about that video. Interesting thoughts though.
Yeah, ads shown as bottom-screen crawls were only around in the EPG Jr. and EPG Sr. days. That feature disappeared with the introduction of Prevue Guide.
AriX
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Re: LISTINGS!

Post by AriX »

tin wrote:This is what I know so far. I'll wiki-ise tomorrow.

Code: Select all

 1 - half hours that defines start of day?		[BCK]	A,B 		(ASCII A = 0, B = 1)
 2 - hours that defines start of day?			[FWD]	C,D,E,I		(ASCII C = 3, D = 4, E = 5)
 3 - transmitted scroll speed (in ascii) 		[SSPD]	1,2,3
 4 - # adverts (in ascii) 10's 				[#AD]	3
 5 - # adverts (in ascii) 1's  				[#AD]	6
 6 - lines in advert (in ascii) 			[LINE]	6,8
 7 - 								N
 8 - something to do with adverts shown, or how often?		$02,$01
 9 - something to do with adverts shown, or how often?		$00,$03
 A - timezone (expressed as ascii where ascii 6 = 0)	[TZ]    3,4,5,6
 B - obey DST 						[DST]	Y,N
 C - 								Y
 D - keyboard enabled						Y,N
 E -								Y,N		not used in atari
 F -								Y,N		not used in atari
10 -								Y,N		not used in atari
11 -								N		not used in atari
12 -							[GRPH]	N,E,L		not used in atari
13 - 							[VIN]	X,L,N		not used in atari
14 - 								X		not used in atari
Seems like things are getting a little bit more active around here again, so I'm just going to note: it seems that at least in the Atari software, the keyboard enabled setting is an "either/or" thing. As in, if the keyboard is enabled and you can type your own ads locally, the machine will NOT receive the satellite delivered ads. Maybe this was already known, but I didn't quite understand until now :)
AriX
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Re: LISTINGS!

Post by AriX »

tin wrote:This is what I know so far. I'll wiki-ise tomorrow.

Code: Select all

 7 - 								N
Have you figured anything out about this byte in the Atari software? It appears to be changed periodically at runtime from N to Y (byte is $0420, settings block stored at $0414)
tin
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Re: LISTINGS!

Post by tin »

AriX wrote: Seems like things are getting a little bit more active around here again, so I'm just going to note: it seems that at least in the Atari software, the keyboard enabled setting is an "either/or" thing. As in, if the keyboard is enabled and you can type your own ads locally, the machine will NOT receive the satellite delivered ads. Maybe this was already known, but I didn't quite understand until now :)
Indeed, the atari code for "L" does this at the start (with my dodgy notes)

Code: Select all

BIGDESOPT13
L0480 = if $4C (L) 
adds a centrally provided message/advert


L933D:      ldy L0482              ; AC 82 04	load Y with L0482
            bne L935B              ; D0 19	skip to (1)  if not zero

					....L0482 is zero - initialise....
            lda #$B3               ; A9 B3
            sta L047C              ; 8D 7C 04	inital checksum

            ldy L0420              ; AC 20 04	(keyboard flag)
            cpy #$59               ; C0 59	
            beq L933A              ; F0 EC	if is $59 ("Y") [ZEROL0480L0482L0483 - set L0480, L0482, L0483 to zero] and back to start of MAINLOOP

<snip>
AriX wrote:
tin wrote:This is what I know so far. I'll wiki-ise tomorrow.

Code: Select all

 7 - 								N
Have you figured anything out about this byte in the Atari software? It appears to be changed periodically at runtime from N to Y (byte is $0420, settings block stored at $0414)
Bit of confusion here, by my records byte 7 of that is stored at $041A, but assuming you mean byte 7, I am reasonably certain it is ignored in Atari (as is byte 6 which is used on Amiga for number of advert lines).
nwgatwcfan
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Re: LISTINGS!

Post by nwgatwcfan »

Quick question. I have noticed something about the scroll on the Prevue Channel. There are some systems that the scroll stops after every three listings. There are others that stop after a movie listing only. And there others (like my cable company did) that continously scroll without stopping or pausing. Could one of the settings be controling this feature that we are unaware of, or has this already been discovered yet?

Thanks,
Steven.
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