*20
LMODE
/PROGRAM ECHASKCH
/SENSE SWITCH 5 TO ERASE SCREEN
/SENSE SWITCH 4 FOR DYNAMIC MODE
/SENSE SWITCH 3 FOR SUSPEND TRACE
RESTRT, CLR
 STC KOUNT
REDO1, SET I 1
 VTAB-1     /VERT. PT.--B1
 SET I 2
 HTAB-1!2000/HORZ. PT.--B2
 SET I 3
 KOUNT
 SET I 17   /ALT KOUNT--B17
 KOUNT2
REDO2, LDA 17
 STA 3
 SET 1      /ALT VERT.--B15
 15
 SET 2      /ALT HORZ.--B16
 16
/
/15,16,17 WILL ALWAYS EQUAL OR BE
/BEHIND 1,2,3
/
NXSAM, SNS I 5
 JMP RESTRT
 SAM 0
 SCR 1
 SAE 1
 JMP CONT
SMPT, JMP SAMP
 SAE 2
 JMP .+3
 LDA 3
 JMP HOLD
 SAM 0
 SCR 1
CONT, SNS 3
 STA I 15  /0--OFF
 STA I 1   /1--ON
 JMP SAMP
 SNS 3
 STA I 16
 STA I 2
 LDA I 
 1
 ADM 3
 SNS 3
 STA 17
HOLD, COM
 STA
 4           /MKOUNT--B4
DISP, SET I 5/HOR PT--B5
 VTAB-1
 SET I 6     /HOR PT--B6
 HTAB-1!2000
REDIS, LDA I 6
 STC 7      /H DISPL--A7
 LDA I 5
 DIS 7
 XSK I 4
 JMP REDIS
 LDA 3
 SAE I
 HTAB-VTAB
 JMP TEST3
 SNS 4
 JMP .+3  /ON--DYNAMIC ERASE
 LDA
 KOUNT    /OFF
 JMP HOLD
 LDA I
 -1
 ADM 17
 XSK 1
 JMP TEST3 /NO
 XSK 17    /YES
 JMP REDO2 /NO
 JMP REDO1 /YES
TEST3, SNS 3
 JMP NXSAM /ON-DOWN
 JMP REDO2
KOUNT,0
KOUNT2, 0
 VTAB-1
VTAB,0
*10
SAMP, SAM 4
 ADA I 
 777
 SCR 1
 JMP 0
HTAB=2000