Atari 400 Hardware Manual

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ATARI 800 CHEC~ERS DISPLAV BV C SHAW 3/31/80
5628
5628
70
5629 70
562A 70
5628 46
562C 0054
562E 80
562F 06
5630 10
5631 07
5632 50
5633 07
5634 50
5635 07
5636 50
5637 07
5638 50
5639 07
563A 50
5638 07
563C 50
563D 07
563E 50
563F 07
5640 10
5641 06
5642 41
5643 2856
5645 48
5646 A956
564S 800904
564B A92D
5640 81)0004
5650 68
5651 40
1180
1190
1~1;)0
12H:t
1220
12:!0
1240
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PAGE
; DISPLAV LIST
DSP
.
BVTE
BVTE
. BVTE
. BVTE
. WORD
BYTE
. BYTE
.
BVTE
. BYTE
. BYTE
. BVTE
. BYTE
. BYTE
. BVTE
.
BYTE
. BVTE
BYTE
. BYTE
. BYTE
.
BYTE
B'T'TE
. BVTE
. BYTE
.
BVTE
. BVTE
. BYTE
WORD
BLANKS ; 24 BLANK LINES
BLANKS
BLANKS
RELOAD+6 ; LINES 0-7 MESSAGE LINE · 20 ACROSS X 5 COLOR X 1 LINE RESOLUTION CHARACTERS
TITL
IIH +BLANK1 ; 8 . INTERRUPT TO CHANGE CHARACTER BASE ADDRESS ANO CHArmE TO r~ARROW SCREEN
6
;9-16 TOP BORDER . 16 X 5 X 1 CHARS <LAST LINE IS TOP OF 1ST ROW OF SOUARES>
BLANK2 ;17-18 . TOP OF FIRST ROW OF SQUARES
7
BLANK6
7
BLANK6
7
BLANK6
7
BLANK6
7
BLANK6
7
BLANK6
7
BLANK6
7
BLANK2
6
JMPWT
DSP
CHECKERBOARD <8 LINES OF CHARS WITH SPACES INBETWEEN - 22 LINES/SQUARE>
;19-34 . 16XSX2 LINE RESOLUTION CHARS
;35-40 . FIRST 3 LINES=BOTTOM OF PREVIOUS SQUARE .
;
41-56
;57-62. LAST 3 LINES=TOP OF NEXT SQUARE .
;
63-78
; 79-84
; 85-100
; 101-106
; 107-122
; 123-128
; 129-144
; 145-150
; 151-166
; 167-172
; 173-188
NEXT THREE LINES ARE BOTTOM OF PREVIOUS SQUARE
;189-190 END OF NORMAL DISPLAV <SHOULD BE ON SCREEN ON ALL TV'S) .
;191-198. BOTTOM BORDER <MAV OVERSCAN, BUT NOT ESSENTIAL TO GAME PLAV>
; WAIT FOR NEXT VBLANIC THEN START OVER
; DSP -- DISPLAV LIST INTERRUPT HAI~DLER.
; CHANGES CHARACTER BASE AND WIDTH OF DISPLAY FOR SPECIAL CHEU'ERS GRAPHICS
;THE OS WILL CHANGE CHBASE BACK TO NORMAL DURING VERTICAL BLANK
NCHR
PHA
LOA tiGR/256
STA CHBASE
; INSTRUCTION FETCH DMA ENABLE, P/M 2 LINE RES, P/M DI1A ENABLE, NAPROW SCREEN <128 CLOCKS>
LOA tl$20
STA DI·1ACTL
PLA
RTI

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)