Re: 131-color mode

[scott@alfter.diespammersdie.us (Scott Alfter)]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

In article <1147323379.578269.85920@i40g2000cwc.googlegroups.com>,
BLuRry <brendan.robert@gmail.com> wrote:
>call-151
>300:ad 50 c0 ad 52 c0 ad 56 c0 20 32 f8 a2 f a9 1f 85 2c 8a 20 64 f8 a0
>0 8a a 18 69 2 20 19 f8 a0 0 8a a 18 69 3 20 19 f8 ca 10 e5 64 3c a9 4
>85 3d a9 ff 85 3e a9 7 85 3f 64 42 a9 8 85 43 20 2c fe 20 32 f8 a2 f a9
>
>34a:21 85 2d 8a 20 64 f8 8a a a8 a9 0 20 28 f8 8a a a8 c8 a9 0 20 28 f8
>ca 10 e8 ad 10 c0 ad 0 c0 30 1c ad 19 c0 10 fb ad 19 c0 30 fb ad 55 c0
>ad 19 c0 10 fb ad 19 c0 30 fb ad 54 c0 80 df ad 51 c0 20 39 fb 20 58 fc
>60
>300g
>
>(hint, paste this to the basic prompt with shift+insert -- nice
>feature, Applewin dev team!!)
>
>Whadda think, folks?  Want to see some 131-color 140x192 graphics next?
>(can anyone tell me why garbage gets written to $800 or so after the
>movemem routine is called?)

You're switching between page 1 and page 2 when the VBI rolls around, right? 
I've only tried your code in an emulator so far, which wouldn't work as well
for this trick as a real Apple II.

Back in the day, I tried the same trick with text and Hi-Res.  Since I had a
monochrome monitor, it was mainly useful for generating dimmer-than-normal
text and 2-bpp grayscale images.  I didn't do anything useful with it at the
time, but it seemed like a neat hack.  (Hmm...2-bpp grayscale would've been
an improvement for viewing bitmapped images over 1-bpp, but I never figured
out image compression until relatively recently.  While I've written a JPEG
compressor and decompressor, they weren't written for the II.)

(BTW, your code requires a 65C02 to run.  It has a couple of STZ
instructions in it...had to look them up in the datasheet because the
Monitor's disassembler didn't know what they were.)

  _/_
 / v \ Scott Alfter (remove the obvious to send mail)
(IIGS( http://alfter.us/            Top-posting!
 \_^_/ rm -rf /bin/laden            >What's the most annoying thing on Usenet?

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.2 (GNU/Linux)

iD8DBQFEY3RDVgTKos01OwkRArErAKDiClz2BMhCNLuViLjtGg8UjzqfkgCeMkGj
1s/A4HU8o/R0Fyug2ELO1xk=
=Fp/X
-----END PGP SIGNATURE-----