Questions about file and rom sizes...

[eddhell]

1) What was the largest cartridge ROM size available during the original Inty run?  I'm guessing the INTV later releases would use the most space.

 

2) What's the largest file size that a developer's flash cart can safely execute?  (LTO or whatever else is out there)

 

I got a game I'm working on and holy shit....you don't realize how long code gets just looking at it on screen, but I had it printed out and it churned up a couple of hundred pages...the compiled ROM is around 45Kb - works (almost) fine with emulator.

 

BTW- is there ANY thing else available out there besides waiting on an overpriced LTO cart?  I would really like to test some homemade roms....

Edited January 17 by eddhell

[+DZ-Jay]

2 hours ago, eddhell said:

1) What was the largest cartridge ROM size available during the original Inty run?  I'm guessing the INTV later releases would use the most space.

 

I believe the largest cartridge size was 16K words.

 

2 hours ago, eddhell said:

2) What's the largest file size that a developer's flash cart can safely execute?  (LTO or whatever else is out there)

 

Without bank-switching, the memory map can support up to 42K words.  With bank-switching, I think that goes over 600K words.

 

I think I read something that the LTO supports a theoretical 1MB size, but I suppose that's mostly for NVRAM, and not for ROM directly.

 

2 hours ago, eddhell said:

I got a game I'm working on and holy shit....you don't realize how long code gets just looking at it on screen, but I had it printed out and it churned up a couple of hundred pages...the compiled ROM is around 45Kb - works (almost) fine with emulator.

 

45Kb is not too bad, that's around 22K words, which is larger than the old Mattel cartridges, but modest for a home-brew.

 

In the Intellivision world, we measure our ROMs in Kilo-words, or DECLEs, because the ROM is 16-bits wide, and the CPU is not byte-addressable.

 

So, when we say that the maximum is 42K, it means 42 thousand 16-bit words, or a file size of about 84Kb.

 

2 hours ago, eddhell said:

BTW- is there ANY thing else available out there besides waiting on an overpriced LTO cart?  I would really like to test some homemade roms....

There is the Backbit and the RTO.  Both of them are readily available and actively supported.

 

   dZ.

 

P.S. What is your game about?  Can you share some screenshots?

[+5-11under]

1 hour ago, DZ-Jay said:

Without bank-switching, the memory map can support up to 42K words.  With bank-switching, I think that goes over 600K words.

From the Cart-mac info: "The 42K map also includes some additional RAM from $8040 to $9EFF" - this space can be set up as ROM space, so you've got closer to 50K words. I think this is supported in most solutions.

[+DZ-Jay]

3 minutes ago, 5-11under said:

From the Cart-mac info: "The 42K map also includes some additional RAM from $8040 to $9EFF" - this space can be set up as ROM space, so you've got closer to 50K words. I think this is supported in most solutions.

Hmmm ... I thought that the 8K of cartridge RAM was counted as part of the 42K, not in addition to it.  That is to say, that the available memory space is 42K in total.

Is that not so?

 

    dZ.

[+5-11under]

3 minutes ago, DZ-Jay said:

Hmmm ... I thought that the 8K of cartridge RAM was counted as part of the 42K, not in addition to it.  That is to say, that the available memory space is 42K in total.

Is that not so?

 

    dZ.

The "map" argument can take on one of two values: 16K or 42K. This selects between two memory maps:

16K:
SEGMENT  RANGE
   0     $5000 - $6FFF
   1     $D000 - $DFFF
   2     $F000 - $FFFF

42K:
SEGMENT  RANGE
   0     $5000 - $6FFF
   1     $A000 - $C020
   2     $C022 - $FFFF
   3     $2000 - $2FFF
   4     $7100 - $7FFF
   5     $4800 - $4FFF

The 42K map also includes some additional RAM from $8040 to $9EFF.

 

You've got ~10.5 4K blocks in the list... 42K. Adding 8 and 9 gives ~12.5 blocks, or 50K.

[+DZ-Jay]

4 minutes ago, 5-11under said:

The "map" argument can take on one of two values: 16K or 42K. This selects between two memory maps:

16K:
SEGMENT  RANGE
   0     $5000 - $6FFF
   1     $D000 - $DFFF
   2     $F000 - $FFFF

42K:
SEGMENT  RANGE
   0     $5000 - $6FFF
   1     $A000 - $C020
   2     $C022 - $FFFF
   3     $2000 - $2FFF
   4     $7100 - $7FFF
   5     $4800 - $4FFF

The 42K map also includes some additional RAM from $8040 to $9EFF.

 

You've got ~10.5 4K blocks in the list... 42K. Adding 8 and 9 gives ~12.5 blocks, or 50K.

 

Yeah, you are right.  I just looked back at the docs and noticed that as well.

 

LTO Flash and JLP boards can treat that 8K block either as ROM or RAM, although the latter is the default, I believe.  However, I believe it cannot split that 8K block into hybrid executable/RAM memory (I believe it is a firmware limitation, as explained to me by Joe Z.).

 

The emulator jzIntv does allow you to configure that 8K as you wish.

 

Personally, I think using that extra 8K as cartridge RAM with 42K of ROM is preferable, since 16-bit on-board RAM is so scarce to begin with.  (On a pinch, if your game if you need more space for data, you could re-purpose blocks of that 8K RAM as buffers and use them to unpack ROM data at run-time, giving you more bang for your memory-buck.)

 

Thanks!

 

      -dZ.

[eddhell]

3 hours ago, DZ-Jay said:

P.S. What is your game about?  Can you share some screenshots?

It's just a project I have to get out of my head.  It's a board game with elements inspired from all kinds of other games I grew up with - Monopoly, M.U.L.E., Risk, old DOS text games like Rockstar, Druglord, Cartels & Cutthroats, stock market sims, etc. and the Fabulous Freak Bros. paper games that were printed or sold in 1980's adult magazines.  It's mostly a trading/smuggling game, with some twists to try to add more replay value.  I made it 1 to 4 players - solo mode is player vs. the environment, while 2 or more players have a basic PVP mode if you land on an occupied square.

 

A couple of warnings:  My graphics are minimal - I'm no pixel artist.  I made very basic sprites, just enough to run and test function with the intent to improve them later.

Also this was 'pieced' together as I worked my way learning Intybasic through Mr. Nanochess' book. I know there are lots of things that could be more condensed and menus that could be reused, etc.  My programming probably has some redundancy, but it's 'almost' failsafe!

 

 

 

[eddhell]

had to make more screenshots, this is not the original drive I started this project on a few years ago.....

 

[+DZ-Jay]

Nice!  Thanks for sharing those.

 

Let us know if you need any help, or if you need some testers.

 

   dZ.

[mr_me]

World Series Baseball released in 1983 is a 24k cartridge.  Hover Force and Tower of Doom were developed at Mattel but released by INTV Corp were also 24k.  The cartridges developed by INTV Corp maxed out at 16k.

[eddhell]

1 hour ago, DZ-Jay said:

Nice!  Thanks for sharing those.

 

Let us know if you need any help, or if you need some testers.

 

   dZ.

I would eventually like it tested by others, but it's not near that point yet.  It's somewhat playable, but my main movement algorithm is large and complicated, making debugging a bitch.  I couldn't figure out an easy way to 'control' the player pieces to force them to conform to movement along a non-linear game board, so each possible move from the player's position is checked and compared against arrays of each 'square' on the game board to prevent any unwanted results....the player merely controls decisions on menus and which direction to move, then the program forces the sprite into the proper spaces.  None of it was done using any type of on screen location/collision detection, but using comparison statements.  (But it works...)

[eddhell]

This is the 'spin' screen, the big wheel has simple color animations when spun.  I decided dice rolls are overused, so I went with a spinner like the big wheel on "Price is Right!"

This was the first section I started on, it's waaaay overblown and could have been done much easier with less code, but I liked it too much to scrap it....

Edited January 17 by eddhell

[Brian's Man Cave]

I like where this is going! Game looks great so far 😃

[TR4SHD4T4]

This looks great.

As for graphics on Intellivision, It's all dodgy. lol. 

Again, looks awesome!