RCA CDP18S711 manual VIP Video Display Drawing Game

Appendix D - Video Games

2. VIP Video Display Drawing Game

This program uses the CHIP-8 INTERPRETER at

0000-01FF. A flashing spot appears in the upper left corner of the screen. You can move the spot by holding key 2, 4, 6, or 8. Press key 5 and you can draw a picture with the spot. Press key 0 and the spot can be moved without drawing or used to erase a previously drawn line. 0245-024E is a list of

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initial values for VO-V9. In this program, locations 0300-03FF are used for the picture. After drawing a picture, you can change M(0208) from OOEO to 120A. Write locations 0000-03FF (4 pages) to tape to save your picture. When you load these four pages back into memory you will see your original picture. Changing the OOEO instruction in the program to 120A prevents your picture from being erased when the program is started.

0200	A245	I=0245
0202	F965	VO:V9=MI
0204	A24F	I=024F
0206	0236	MLS@0236
0208	OOEO ERASE
020A	F915	TIME-V9
020C	FA07 VA=TIME
020E	3AOO SKIP;VA EQ 00
0210	120C	GO 020C
0212	D121	SHOW 1MI@V1V2
0214	3FOO SKIP;VF EQ 00
0216	D121	SHOW 1MI@VIV2
0218	E3A1 SKIP;V3 NE KEY
021A	8030	VO=V3
021C	E4AI SKIP;V4 NE KEY
O~U 8040 VO=V4
0220	4000	SK1P;VO NE 00
0222	123C	GO 023C
0224	E5A1 SKIP;V5 NE KEY
0226	72FF V2+FF

0228	E6A1 SKIP;V6 NE KEY
022A	71FF V1+FF
022C	E7AI S&IP;V7 NE KEY
022E	7101	V1+01
0230	E8A1 SKJP;V8 NE KEY
0232	7201	V2+01
0234	120A	GO 020A
0236	OlF8
0238	03BB
023A	E2D4	SHOW 1MI@V1V2
023C	D121
023E	4FOO SKIP;VF NE 00
0240	D121	SHOW 1MI@V1V2
0242	1224	GO 0224
0244	0100
0246	0000
0248	0005
024A	0204
024C	0608
024E	0880