Pascal

From Ninerpedia
Revision as of 10:33, 15 October 2014 by Stephen Shaw (talk | contribs) (→‎UCSD Pascal System: add note re adding UNITs to SYSTEM.LIBRARY)
Jump to navigation Jump to search

UCSD Pascal System

P-Code welcome screen, booted with Editor/Filer disk

=File doesn't exist

PASCAL NOTE: Guy Stefan-Romano, 99ers Users Group. Sept 1984:

'FILE DOESN'T EXIST" after adding a UNIT to SYSTEM.LIBRARY:

In most USCD Pascals. the system is not provided with a SYSTEM.LIBRARY. TI placed parts of Pascal that would normally reside on disk/ram into chips on the card, to allow our tiny machine to run Pascal. TI also provided a SYSTEM.LIBRARY to allow use of sound, graphics. speech etc.

Because installation of a new UNIT into a SYSTEM.LIBRARY requires that a file be open while data is manipulated, the existing SYSTEM.LIBRARY data is quite vulnerable. TI added protection.

You need to call a temporary File -say USER.LIB. transfer all UNITS in SYSTEM.LIBRARY to USER.LIB, then add your new UNITS to USER.LIB and IF all goes well, rename the USER.LIB file SYSTEM.LIBRARY


What is P-Code?

P-Code can be thought of as a universal assembly type language. P-Code was developed to be transportable to different platforms for execution. The TI-99/4A supports P-Code with the use of the P-Code card. Some other platforms that support P-Code are: Z80, Motorola 6800/68000, Intel 8086/8088 and many others.

Turbo Pasc'99

add text