John, When I worked VSE many moons ago , we build a buffer area between the end of the program and end of the partition, then build a bitmap to reference it. Like the old f.rt I am I didn't save the code..but I like your idea..
Scott ford www.identityforge.com from my IPAD > On Feb 19, 2014, at 8:20 AM, John McKown <[email protected]> wrote: > > On Tue, Feb 18, 2014 at 10:02 PM, Robert A. Rosenberg > <[email protected]>wrote: > >> At 17:42 -0500 on 02/18/2014, Gerhard Postpischil wrote about Re: >> assembler: >> >> >> You seem to be deliberately confounding the issue. There is no efficient >>> way of testing the validity of a bit number using only bytes. Let me >>> simplify this for you - when the OP has 62 stores, then the allocation >>> obviously is for a minimum of 8 bytes, but the value for checking validity >>> of a bit is 62, not 8, and not 8*8. >> >> That is true. OTOH, once you validate the store number, the bit number >> (ie: Offset into the byte) is mod (store#,8) [IOW: The remainder of >> dividing the store# by 8] and the byte offset is floor(store#/8). Thus >> there is no way to get a bit number of 6 or 7 in byte 8 since these bits >> are invalid with only 62 stores. > Going a bit OT on this, but this talk about bits - the testing and setting > thereof, makes me curious about why IBM doesn't simplify it a "bit" (pun > intended). They have done some, such as with Find LeftMost One and > Population Count (could somebody explain to me what this might really be > used for?). So why not a "test bit" instruction, instead of needing to > generate a "bit mask" from the "bit number", then do something like an EX > of an NI or some such (as I'm sure many have seen and done). This could be > a simple RX format instruction. The register would contain the bit number, > from 0 to 7 (specification exception if not in range), > > SLR R0,R0 > L R1,STORE_NUM > D R0,=F'8' > TBIT R0,STORE_BIT_STRING(R1) > JZ CLOSED > > > -- > Wasn't there something about a PASCAL programmer knowing the value of > everything and the Wirth of nothing? > > Maranatha! <>< > John McKown > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
