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Maximizing the playfield


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I am tinkering with the DLL lines a bit. The cc65 could have a conio target for testing and small games. The "Robot finds kitten" game used 24 lines.  Here is a 28 line version of it that appears to run nicely on the emulator in PAL and NTSC with a 224 lines playfield.



Is this usable on real monitors? Or should I stay with less lines?

Here is the build for 224 scanlines (28 text lines).



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9 hours ago, karri said:

Is this usable on real monitors? Or should I stay with less lines?
Here is the build for 224 scanlines (28 text lines).

The average visible lines on a typical CRT display is 224 lines.  It is one of the reasons why consoles of the 8-bit and 16-bit error will state and/or keep their resolution at no more than ###x224.  Typically, the most heavily used resolution, when a console contained multiple resolutions, is 224 scanlines.  There was a thread also on AtariAge surrounding it. 


Under the 7800, the retail games Tank Command and Water Ski are 224 scanlines. 


Below is a guideline respecting it, as denoted with RevEng's Safe Screen Utility ROM:




Keep in mind that emulation/emulators tend to lean towards a centered output screen.  My experience has been that on average, the output from the 7800 appears ~3 to 4 scanlines downward justified on a CRT.  However, there have been those who have noted an upward justification of approximately the same number of scanlines instead.


NesDev has a good section covering the topic overall as well.

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Thank you!

As there is such a big difference with PAL and NTSC I am leaning towards the 224 lines in the conio implementation. Here is a first snapshot of some old adventure that I had hanging around. Running on the experimental cc65 conio target on the a7800. The background is just some experimental artwork using the VGA font.
It is really amazing that the 4k of RAM is enough for holding an adventure game.


Segment list:
Name                   Start     End    Size  Align
EXEHDR                000000  00007F  000080  00001
ZEROPAGE              000040  000059  00001A  00001
DATA                  001800  001A83  000284  00001
BSS                   001A84  00202B  0005A8  00001
CODE                  008000  00A90E  00290F  00001
RODATA                00AA00  00DF03  003504  00100
STARTUP               00FEAE  00FEE8  00003B  00001
ONCE                  00FEE9  00FF3A  000052  00001
ENCRYPTION            00FF7A  00FFF9  000080  00001
VECTORS               00FFFA  00FFFF  000006  00001


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