# Domain/OS calls: ct_$

## Cartridge Tapes

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- int /* void? */ ct_$acquire(short &unit, status_$t *status);
- ct_$acquire_u
- int /* void? */ ct_$control(short &unit, short &how, short &count, status_$t *status);
- ct_$diag
- ct_$mrk_rls
- ct_$read
- int /* void? */ ct_$release(short &unit, boolean &haltflag, status_$t *status);
- ct_$release_u
- int /* void? */ ct_$wait(short &unit, short &timeout, short *count, status_$t *status);
- ct_$write

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