Relative File Mechanics – Butterfield, Jim

Compute! Issue 11, Volume 3, No. 4, April 1981, p. 122

Working RELative files in BASIC 4.0 on the PET/CBM.

Working With BASIC 4.0 – Butterfield, Jim

Compute! Issue 11, Volume 3, No. 4, April 1981, p. 136

Miscellaneous BASIC 4.0 tips: routing machine-language monitor output to print ... bling IEEE-488 timeouts.

Disabling the STOP Key – Butterfield, Jim

Compute! Issue 11, Volume 3, No. 4, April 1981, p. 141

Disabling the STOP key in BASIC for all PET/CBM ROM revisions.

Machine Language: The Wonderful Wedge – Butterfield, Jim

Compute! Issue 11, Volume 3, No. 4, April 1981, p. 152

Outline of the wedge technique for adding new commands to BASIC. Includes source code.