From: Paul Repacholi [prep@prep.synonet.com] Sent: Sunday, March 18, 2001 7:07 AM To: Info-VAX@Mvb.Saic.Com Subject: Re: RMS and file types. "Bill Todd" writes: > That's a good explanation of what I remember, but, though I spent > quite a bit of time working with the VMS developers trying to get > streams of various types to work 'right', I never knew exactly how > everything turned out. Did the VMS implementation wind up straying > from what we did on RSX, and if so, how? Two places, woops, 3 places. RSX treated the record length as a 16 bit unsigned with the majik-happens reserved value of 177777 as 'go to next block', VMS/ODS-2 defines it as a signed value. ( Makes you wonder what a -42 byte record means... ) VFC record with no Carriage Control used the control word as a sequence number. This was used by several utilities for patching etc. Tops-10 had the same sort of facillity, but used bit 35=1 to indicate it was a sequence number, not 5 7 bit bytes. Undefined records type. All sorts of things on RSX where UDF record type, .OBJs and .TSKs come to mind, but don't quote me. VMS set all of these as 512 byte records, and does not use the UDF type at all. The first was a non-event for RSX, I never saw a >32K record from a RSX system. Given the 64K address limit, not a suprise! Sequence numbered files, likewise are a pretty small odd corner case, but I have been bitten by that long ago. The UDF -> 512 fixed has had practical impact I think. One is getting a 'not-defined' file as 512 fixed, and it has embedded CC chars. The new free record boundaries give you extranious line breaks. I used to have a TECO macro to re-mung these. I also suspect this is tied into the 'user buffer exceded' error message. As a late thought. Tops used to define an end of line as a 'vertical format effector'. IE Vertical Tab, Form Feed, Line Feed, and perhaps some of the 'End...' codes. I wonder if STM records do this? That is rather than . ( I'm doing a Tops-10 install right now, in case you wondered where that came from. ;) ) -- Paul Repacholi 1 Crescent Rd., +61 (08) 9257-1001 Kalamunda. West Australia 6076 Raw, Cooked or Well-done, it's all half baked.