View Full Version : CPM 2.2 - F_SIZE always returns 255...

February 19th, 2018, 05:06 PM
I'm testing BDOS functions and with CP/M 3.1 when I do a F_SIZE on a file, it returns the number of records in the FCB and the status = 0 which I expect.

When I repeat the same test with CP/M 2.2, it does properly return the number of records, but it also returns 255 which is an error. Is this normal for 2.2?

February 20th, 2018, 02:56 AM
According to the CP/M 2.2 manuals, BDOS function 35 (23H) does not return a result code in A (or HL). So, I would suspect the 255 value in A has no meaning. CP/M 3 does return a result code (and extended error code).

February 20th, 2018, 07:13 AM
How many manuals are there for CP/M 2.2? I am only seeing one - is there a programmers manual?

February 20th, 2018, 07:54 AM
Here are some (http://bitsavers.informatik.uni-stuttgart.de/pdf/digitalResearch/cpm/)