Norman, I haven't got the slightest idea why this is so.
To my knowledge, heap memory allocations should be rounded up to multiples of 16 (and, at least Minerva sources confirm that). Tobias Am 07.10.2013 um 21:36 schrieb Norman Dunbar: > Evening all, > > I'm experimenting for the first exciting episode of the new assembly language > mailing list. It's the first time I've sat down with QPC since I started my > new job! > > I have noticed something a little odd, well, even to be honest. Strangely > enough, the answer is 42 - what is the question? ;-) > > Seriously, when I create a job with any given dataspace, when the job is > activated, A5.L is always set to that data space value plus 42 extra bytes. > > There's nothing in the QDOS docs (from Jochen) nor in Dickens or Pennell. The > closest I have found is in Pennell on page 20 where he says that "... TRNSP > is expanded by D2+D3+$68, memory permitting" when a job is created. > > D2 is the code size, D3 is the requested dataspace size and the extra $68 is > for the standard job header area. > > I'm wondering if the mysterious 42 extra bytes is also accumulated in the > space desired in TRNSP (it has to be D2+D3+$68+42 or stuff would crash!) but > where does it come from? > > I cannot see it as being a rounding to the nearest 16 or 8 or whatever, > because it's always 42. When I say always, I have tried the same job with the > following dataspace sizes, and every one set A5 to be 42 extra: > > 126, 256, 500, 512, 1000, 1024, 2000, 2048, 3000, 3172, 4000, 4096. > > I could, I suppose, look up the source for SMSQ but I don;t, sadly, have the > time at the moment. Not after doing all the above testing! I'm afraid I shall > be lazy and rely on the good will and knowledge of the list for answers. > > Thanks in advance. > > > Cheers, > Norm. > > -- > Norman Dunbar > Dunbar IT Consultants Ltd > > Registered address: > 27a Lidget Hill > Pudsey > West Yorkshire > United Kingdom > LS28 7LG > > Company Number: 05132767 > _______________________________________________ > QL-Users Mailing List > http://www.q-v-d.demon.co.uk/smsqe.htm _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
