To Input Ports

That no input is missed, these instructions should be contained in a loop, with a branch out only when a character is read. To output data to the TTY an INP9, x instruction will again result in the status word being output on the data bus. This time, however, we are interested in bit 0, which will be the TBMT flag transmitter buffer empty . If the TBMT flag is a 1 then the data may be output to the UART for transmission. To do this, an OUT9, x instruction is required. Note that during...

Style

Some useful routines. Bruce Stock. UTILITY 46 SPOOL amp DeSPOOL. Split personality when printing. H.S. Gentry. 80 Test Your Memory. See if your chips are absent-minded. Milan Chepko 105 LPRINT Routines. Hardcopy Video. Craig Werner. 115 Whazlt Read your tapes. J.B. Penny. 122 Screen Editor. Non-destructive cursor. William Colsher 125 Extra Errors. On Error read this. Charles Moses. REGULARS 8 80 Remarks. Wayne Green. 8 80 Applications. Dennis Kitsz. 10 Club 80. Ross Wirth....

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' ERR Error Code - 1 2 or ERR 2 1 Error Code ON ERROR GOTO 0 is the way you get out o the error-trapping routine and let Level II handle the error. Level II will pass over the commas as though they were line numbers. If ERR 2 1 's a value for which there is no line number you will get a UL ERROR IN 1010 error ON ERR 2 1 GOTO statement, containing the single statement ON ERROR GOTO O. Number 3, the most difficult, was satisfied using another curious ability of Level II A command, like RUN or...

Expansion Moouu

DOUBLE OCNSiTV I CONHGURATION I 4K BYTES , The expansion Module provides a double density modification to your current Radio Shack interface that allows you to format diskettes in either single or double density. In double density format, your Vista Drive increases your storage capacity up to 204K bytes on a single 40-track drive. To insure the highest performance possible, without compromise, we recommend that you use Vista disk drives in conjunction with our Expansion Module For a...