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Routines |
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The address of this routine is found in the parameter table.
This command allows the user to OPEN streams. A channel code must be supplied and it must be 'K', 'k', 'S', 's', 'P', or 'p'.
Note that no attempt is made to give streams 0 to 3 their initial data.
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| OPEN | 05942 | RST 40 | Use the calculator to exchange the stream number and the channel code. | |
| 05943 | DEFB 1 | exchange | ||
| 05944 | DEFB 56 | end_calc | ||
| 05945 | CALL STR_DATA | Fetch the data for the stream. | ||
| 05948 | LD A,B | Jump forward if both bytes of the data are zero, i.e. the stream was in a closed state. | ||
| 05949 | OR C | |||
| 05950 | JR Z,OPEN_1 | |||
| 05952 | EX DE,HL | Save HL. | ||
| 05953 | LD HL,(23631) | Fetch CHANS - the base address of the channel information and find the code of the channel associated with the stream being OPENed. | ||
| 05956 | ADD HL,BC | |||
| 05957 | INC HL | |||
| 05958 | INC HL | |||
| 05959 | INC HL | |||
| 05960 | LD A,(HL) | |||
| 05961 | EX DE,HL | Return HL. | ||
| 05962 | CP "K" | The code fetched from the channel information area must be 'K', 'S' or 'P'; give an error if it is not. | ||
| 05964 | JR Z,OPEN_1 | |||
| 05966 | CP "S" | |||
| 05968 | JR Z,OPEN_1 | |||
| 05970 | CP "P" | |||
| 05972 | JR NZ,REPORT_O_2 | |||
| OPEN_1 | 05974 | CALL OPEN_2 | Collect the appropriate data in DE. | |
| 05977 | LD (HL),E | Enter the data into the two bytes in the stream information area. | ||
| 05978 | INC HL | |||
| 05979 | LD (HL),D | |||
| 05980 | RET | Finally return. | ||
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