+Random Terrain Posted September 22, 2011 Share Posted September 22, 2011 (edited) This thread is based on this post: http://www.atariage....58#entry2371858 The registers like AUDV1, GRP0, NUSIZ1, etc are write-only. You can't read what's been put in them. I went Googling for "write-only" and "Atari 2600" and found the TIA - WRITE ADDRESS SUMMARY (Write only) list on this page: http://nocash.emubase.de/2k6specs.htm#memoryandiomap The following is an adapted version of that list for batari Basic users: NUSIZ0 number-size player-missile 0 NUSIZ1 number-size player-missile 1 COLUP0 color-lum player 0 and missile 0 COLUP1 color-lum player 1 and missile 1 COLUPF color-lum playfield and ball COLUBK color-lum background CTRLPF control playfield ball size & collisions REFP0 reflect player 0 REFP1 reflect player 1 PF0 playfield register byte 0 AUDV0 audio volume 0 AUDV1 audio volume 1 AUDC0 audio control 0 AUDC1 audio control 1 AUDF0 audio frequency 0 AUDF1 audio frequency 1 Except for Superchip RAM, is that a complete list of write-only addresses for batari Basic? Thanks. Edited September 22, 2011 by Random Terrain Quote Link to comment Share on other sites More sharing options...
alex_79 Posted September 22, 2011 Share Posted September 22, 2011 All TIA registers (and a few RIOT ones) are either read-only or write-only. In fact the same address is usually shared by two registers. For example, address $0008 is COLUBK if you write into it, and INPT0 (paddle line 0) if you read from it. You can find a complete 2600 memory map, including all TIA and RIOT registers in this post. Quote Link to comment Share on other sites More sharing options...
+Random Terrain Posted September 22, 2011 Author Share Posted September 22, 2011 All TIA registers (and a few RIOT ones) are either read-only or write-only. In fact the same address is usually shared by two registers. For example, address $0008 is COLUBK if you write into it, and INPT0 (paddle line 0) if you read from it. You can find a complete 2600 memory map, including all TIA and RIOT registers in this post. Thanks. Quote Link to comment Share on other sites More sharing options...
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