Of the 5 differences between Tutorvision and a standard Intellivision, the one that matters here is that it has 4 times as much Graphics RAM. Programmers can pre-define 256 tiles, whereas the Intellivision only allows for 64. Little Man Computer takes full advantage of this in the Simulation screen:
- 56 tiles for the Little Man animations
- 8 tiles for the spinning '?' symbol (the cursor)
- 36 tiles for the decorations around the mailboxes
- 28 tiles for two letters packed into a single tile
- 100 tiles for two digits packed into a single tile
- 10 tiles for a single digit packed on the left side
- 10 tiles for a single digit packed on the right side
- 1 tile for the minus sign packed on the left side
- 5 tiles for the minus sign and one of the digits 1-5
- 2 tiles for the down and right arrows (the up and left arrows are in Graphics ROM)
Another key difference is that the Graphics ROM is different on a Tutorvision than the original Intellivision. In particular, the two arrows in Graphics ROM are shaped differently. The first thing that happens when you start up, before the title screen even appears, is that the program checks for amount of Graphics RAM and which Graphics ROM you're using. After the title screen, it fetches the appropriate shapes for the down and right arrows to match the up and left arrows.
Last edited by intylab on Sun 01 Aug 2021, 6:54 am; edited 1 time in total (Reason for editing : Typo)
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