My first steps into making Intv GFXs

[+Lathe26]

About the 64 tile limit... I've been curious about the what is the root cause of the limit and have not had the time (yet) to review the SDK documentation. Is the 64 tile limit due to a bit field limitation (ex: the STIC indexes card with a 6-bit number) or is it a GRAM size limitation (i.e. if I replaced the GRAM with 2x the memory to create a non-standard Intellivision, there would be a 128 tile limit) or is there some other root cause.

[+intvsteve]

I suspect that the limitation is simply due to the amount of RAM dedicated to graphics. A nice condensed rundown of the bit layout used in the various STIC modes is here. The GRAM is 512 bytes of 8-bit RAM. Each 8x8 pixel tile (card) uses 8 bytes, so that's where the limit comes from. Not sure what other restrictions came to play beyond that.

[intvnut]

About the 64 tile limit... I've been curious about the what is the root cause of the limit and have not had the time (yet) to review the SDK documentation. Is the 64 tile limit due to a bit field limitation (ex: the STIC indexes card with a 6-bit number) or is it a GRAM size limitation (i.e. if I replaced the GRAM with 2x the memory to create a non-standard Intellivision, there would be a 128 tile limit) or is there some other root cause.

 

The 64 tile limit is entirely due to the 512 byte GRAM. The STIC actually can support up to 256 GRAM tiles if you connect enough GRAM.

 

If you want to try making a non-standard Intellivision, you can do it more easily than you realize. Keep in mind, though, that without some additional logic, you'll possibly break some games. They may use the additional, unused address bits to store flags, or they may just be sloppy.

 

The Intellivision 2 actually has 1K of GRAM, but wires it up so that only 512 bytes is usable, for compatibility purposes. I actually hacked an Intellivision 2 to enable all 128 GRAM cards and it works. Read about it here:

 

https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5884

 

 

If you want to hack the hardware further, you can actually double the vertical resolution of the Intellivision (make each tile 8x16 instead of 8x8) as I did in this hack: https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5930

 

Note that that last hack was incomplete, but it demonstrated the feasibility. I was just working with the random chips in my parts bin. Also, I'm not sure it was 100% compatible with MOBs. You likely would need to limit MOBs to 8x8 tiles by copying the same graphics into both the "even" and "odd" rows of the new 8x16 tiles.

 

Yes, the STIC can be augmented in two rather interesting ways, just by putting some more memory around it, and in the case of the double-res, a little bit of glue logic.

[Rev]

Maybe opcode could make some kind of intv super game module!

[+intvsteve]

 

The 64 tile limit is entirely due to the 512 byte GRAM. The STIC actually can support up to 256 GRAM tiles if you connect enough GRAM.

 

If you want to try making a non-standard Intellivision, you can do it more easily than you realize. Keep in mind, though, that without some additional logic, you'll possibly break some games. They may use the additional, unused address bits to store flags, or they may just be sloppy.

 

The Intellivision 2 actually has 1K of GRAM, but wires it up so that only 512 bytes is usable, for compatibility purposes. I actually hacked an Intellivision 2 to enable all 128 GRAM cards and it works. Read about it here:

 

https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5884

 

 

If you want to hack the hardware further, you can actually double the vertical resolution of the Intellivision (make each tile 8x16 instead of 8x8) as I did in this hack: https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5930

 

Note that that last hack was incomplete, but it demonstrated the feasibility. I was just working with the random chips in my parts bin. Also, I'm not sure it was 100% compatible with MOBs. You likely would need to limit MOBs to 8x8 tiles by copying the same graphics into both the "even" and "odd" rows of the new 8x16 tiles.

 

Yes, the STIC can be augmented in two rather interesting ways, just by putting some more memory around it, and in the case of the double-res, a little bit of glue logic.

Awesome! I started looking at the schematic and in two minutes of squinting at a substandard image online, couldn't see anything obvious that would have prevented more RAM from being accessed... I wonder... did the Intellivision II contain that extra GRAM with the goal of increasing GRAM cards, but then they balked due to compatibility concerns?

 

Combine more GRAM cards with double vertical resolution and you've got a "true" Intellivision II. Or maybe Intellivision II.V.

[intvnut]

Awesome! I started looking at the schematic and in two minutes of squinting at a substandard image online, couldn't see anything obvious that would have prevented more RAM from being accessed... I wonder... did the Intellivision II contain that extra GRAM with the goal of increasing GRAM cards, but then they balked due to compatibility concerns?

 

Combine more GRAM cards with double vertical resolution and you've got a "true" Intellivision II. Or maybe Intellivision II.V.

 

I'm going to guess by 1982, the 256 byte SRAMs they were using were obsolete, and 2114s were probably dirt cheap. Most of the world was moving on to systems built from 16K DRAMs by that point anyway, and 64K memories weren't far away. I seem to recall later Intellivision I logic boards (or were they INTV System III boards?) converted to 2114s also.

 

The only reasons you wouldn't wire up the extra memory:

• Cost
• Compatibility in "both directions."

Cost was the key driver. The Intellivision was expensive, new competitors were arriving, and so to compete, Intellivision had to come down in price. Remember, when the Intellivision was first introduced, it was over $900 in today's dollars.

 

Compatibility with existing Intellivision I titles was obviously a requirement—well, except for those pesky 3rd party carts they stupidly wanted to lock out. Adding more RAM meant doing it in a way that wouldn't affect existing games, which for GRAM suggests you'd need a way to shut the extra GRAM off. That negatively affects cost. See first bullet. :-)

 

But there's also a different sort of compatibility: Compatibility of future titles with Intellivision I. When you already have a couple million units out there, you don't want new titles to leave those folks in the lurch. So, at least with the Intellivision II, I seem to recall they explicitly did not want to add any new functionality or even change existing functionality, with the fear that Intellivision II specific titles would start popping up (either intentionally or unintentionally), leaving Intellivision I owners in the cold. At least, that's the impression I get from the description of the square-root "bug" in the EXEC, and the decision not to fix it on the Intellivision II.

 

Sure, we know Intellivision III was going to provide new functionality, but that would have been for Christmas 1984 at the earliest, and by then Intellivision would be 5 years old or so (at least in the broad market; 6 years since test marketing).

Edited March 17, 2014 by intvnut

[retroillucid]

Ok, I managed to use less than 64 cards per screens (remaining cards for character, enemy)

I don'y think I could have done better than this

 

Here's the result

 

 

[Rev]

Looks great! Now when will you be porting over pitfall 2?

 

Those trees in the background just reminded me of that. :-)

Edited March 17, 2014 by revolutionika

[retroillucid]

Looks great! Now when will you be porting over pitfall 2?

Those trees in the background just reminded me of that. :-)

In fact, Pitfall 2 would be more easy to port the GFXs

 

I already started working on Intv version of Tarzan

 

But for now, I'm going to make the Montezuma's Revenge graphics for the Intv

 

[scalpel]

In fact, Pitfall 2 would be more easy to port the GFXs

 

I already started working on Intv version of Tarzan

 

But for now, I'm going to make the Montezuma's Revenge graphics for the Intv

 

 

Seriously ?? Could be GREAT !!!

[Rev]

In fact, Pitfall 2 would be more easy to port the GFXs

 

I already started working on Intv version of Tarzan

 

But for now, I'm going to make the Montezuma's Revenge graphics for the Intv

 

 

 

You are a Beast! Or a Beauty? hmmmmmm

Edited March 17, 2014 by revolutionika

[retroillucid]

You are a Beast! Or a Beauty? hmmmmmm

... I think I would vote for Beast

[+cmart604]

Maybe one day we'll be able to play all the Coleco for Inty vapourware....one can dream.

[retroillucid]

Maybe one day we'll be able to play all the Coleco for Inty vapourware....one can dream.

This's something I'm seriously considering ....

Like I've been doing with the ColecoVision vaporwares

[mr_intv]

Whoa! Did someone say Montezumas Revenge? Looks like im going to need a second job to get all these games if they see the light of day!

[retroillucid]

Whoa! Did someone say Montezumas Revenge? Looks like im going to need a second job to get all these games if they see the light of day!

Oh, they will

[mr_intv]

Oh, they will

That is fantastic! I have already told mrs_intv she needs to get a second job......errr she already has 2! But she can get a 3rd!?

[Rev]

That is fantastic! I have already told mrs_intv she needs to get a second job......errr she already has 2! But she can get a 3rd!

 

(song) She works hard for your games, so you better treat her right!

[mr_intv]

Time Pilot and Pepper II would be great as well. You can du it!

[retroillucid]

Time Pilot and Pepper II would be great as well. You can du it!

How scrolling works on Intv ?

Any places to look for docs?

 

Might be able to do those for sure

[Rev]

How scrolling works on Intv ?

Any places to look for docs?

 

Might be able to do those for sure

 

Not sure. But will this thread help?

 

http://atariage.com/forums/topic/222417-intybasic-smooth-scrolling/?view=findpost&p=2937671&hl=%2Bscrolling

[retroillucid]

Here's my WIP of Montezuma's Revenge

[+cmart604]

Cool

[Rev]

Here's my WIP of Montezuma's Revenge

 

Sweet. You are Beast........oh wait......

[+Lathe26]

 

The 64 tile limit is entirely due to the 512 byte GRAM. The STIC actually can support up to 256 GRAM tiles if you connect enough GRAM.

 

If you want to try making a non-standard Intellivision, you can do it more easily than you realize. Keep in mind, though, that without some additional logic, you'll possibly break some games. They may use the additional, unused address bits to store flags, or they may just be sloppy.

 

The Intellivision 2 actually has 1K of GRAM, but wires it up so that only 512 bytes is usable, for compatibility purposes. I actually hacked an Intellivision 2 to enable all 128 GRAM cards and it works. Read about it here:

 

https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5884

 

 

If you want to hack the hardware further, you can actually double the vertical resolution of the Intellivision (make each tile 8x16 instead of 8x8) as I did in this hack: https://groups.yahoo.com/neo/groups/intvprog/conversations/topics/5930

 

Note that that last hack was incomplete, but it demonstrated the feasibility. I was just working with the random chips in my parts bin. Also, I'm not sure it was 100% compatible with MOBs. You likely would need to limit MOBs to 8x8 tiles by copying the same graphics into both the "even" and "odd" rows of the new 8x16 tiles.

 

Yes, the STIC can be augmented in two rather interesting ways, just by putting some more memory around it, and in the case of the double-res, a little bit of glue logic.

 

Cool, I was really suspecting it was a memory limitation.

 

BTW, given what hardware video tricks you've already implemented, I'm wondering if you've yet tried recreating the double-resolution white-text overlay trick the TutorVision had. In other words, attempted to drive pin 14 (Ext Video) on the AY-3-8915 Color Processor Chip.