Post Reply 
41C ROMs: LBL linkages
09-01-2019, 04:42 AM
Post: #4
RE: 41C ROMs: LBL linkages
The global label links are the same as in RAM and they are fully deterministic in a ROM stored program.

What happens in COPY is that the old .END. becomes a new local END. Then copying takes place from ROM to RAM. The two words tell the number of registers needed (to ensure there is enough space for it) and the number or bytes to load for the first register. The reason for the latter is that the .END. is always right aligned in a register. Thus, it inserts 00 bytes to ensure that the END eventually coming from the ROM will end up right aligned in its register, as this will be the new .END.

In other words, the link from the first global alpha should point to the preceding END (which was the .END. before COPY), and given the algorithm, its location is known and always the same relative to the copied program.
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
41C ROMs: LBL linkages - RobertM - 08-28-2019, 12:21 AM
RE: 41C ROMs: LBL linkages - Ángel Martin - 08-28-2019, 04:56 AM
RE: 41C ROMs: LBL linkages - RobertM - 08-28-2019, 01:57 PM
RE: 41C ROMs: LBL linkages - hth - 09-01-2019 04:42 AM
RE: 41C ROMs: LBL linkages - RobertM - 09-04-2019, 08:41 PM
RE: 41C ROMs: LBL linkages - hth - 09-04-2019, 09:45 PM
RE: 41C ROMs: LBL linkages - RobertM - 09-05-2019, 12:10 AM
RE: 41C ROMs: LBL linkages - hth - 09-05-2019, 01:27 AM
RE: 41C ROMs: LBL linkages - Ángel Martin - 09-05-2019, 07:50 AM
RE: 41C ROMs: LBL linkages - hth - 09-05-2019, 04:32 PM



User(s) browsing this thread: 1 Guest(s)