Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
Johnny Billquist wrote: > Right. But that sounded what the OP was looking for. He noted that > serial number and information was written to the pack. The serial > number is never, as far as I can remember, for any disk drive, written > anywhere in any header fields or similar. The ITS program called SALV apparently retrieves the drive serial number with a device command, then proceeds to write this number to every sector header, in the first key field. The second key field holds the pack number, as specified by the user when formatting the pack. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
On 2019-06-28 15:45, Paul Koning wrote: On Jun 28, 2019, at 3:07 AM, Johnny Billquist wrote: From a hardware point of view, sector header "Word 3" and "Word 4" have no particular meaning. Just for completeness, can you point me to a reference where "pack number" is defined or used by the software? Search for DEC standard 144. If nothing else, I think there is a description in the RL11 documentation. (Me trusting my memory once more...) That's different, though. It describes the bad block table, which includes a pack serial number in its header. Some device types use 144, some do not (in particular, on RP/RM there is a mix -- RP04/5/6 do not, RP07 and RM02/3/5/80 do). The 144 table is purely a software construct, a bit of data placed by convention in the last few sectors of the drive and interpreted by the OS. For example, in RSTS the bad block table is read to mark those blocks as unavailable, and the serial number is read and displayed during formatting but not otherwise used for anything. Right. But that sounded what the OP was looking for. He noted that serial number and information was written to the pack. The serial number is never, as far as I can remember, for any disk drive, written anywhere in any header fields or similar. It's always just on a normal block. Most packs that have anything reserve the last track or similar for this kind of information. And that is what DEC STD 144 is about. For disk packs that do not follow that standard (if we only talk about DEC disks here), then there is no common area where a serial number will be stored. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
FWIW: When Ted and I wrote fcsk in the mid 1970s, (after some arguing about assuming perfect media) we added the notion of a bad block list to the assign to the bad block file (it was not in the original code), but we knew nothing about BAD144 at the time since we both were students. Ultrix [and Tru64] was later fixed (early 80s) to obey BAD144 (thank you, Fred Canter). IIRC, that part of the Ultrix code got sent back to UCB and showed up in some later versions, but I've forgotten. As I recall, the Unix driver was modified after getting a bad block error from the controller, to mark the block as bad and pick a replacement from BAD144. The problem was that the caused stray seeks under the covers after the reformat. I remember having a conversation with Fred at one time approx 1981-2 ish, about not doing the replacement at all if the block was in the free list, then assigning to the bad file so the seeks never occurred (*i.e.* creating perfect media - which is what UNIX assumed). I've forgotten the result of that conversation. ᐧ On Fri, Jun 28, 2019 at 9:46 AM Paul Koning wrote: > > > > On Jun 28, 2019, at 3:07 AM, Johnny Billquist wrote: > > > >> From a hardware point of view, sector header "Word 3" and "Word 4" have > >> no particular meaning. Just for completeness, can you point me to a > >> reference where "pack number" is defined or used by the software? > > > > Search for DEC standard 144. If nothing else, I think there is a > description in the RL11 documentation. (Me trusting my memory once more...) > > That's different, though. It describes the bad block table, which > includes a pack serial number in its header. Some device types use 144, > some do not (in particular, on RP/RM there is a mix -- RP04/5/6 do not, > RP07 and RM02/3/5/80 do). The 144 table is purely a software construct, a > bit of data placed by convention in the last few sectors of the drive and > interpreted by the OS. For example, in RSTS the bad block table is read to > mark those blocks as unavailable, and the serial number is read and > displayed during formatting but not otherwise used for anything. > > paul > > > ___ > Simh mailing list > Simh@trailing-edge.com > http://mailman.trailing-edge.com/mailman/listinfo/simh ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
> On Jun 28, 2019, at 3:07 AM, Johnny Billquist wrote: > >> From a hardware point of view, sector header "Word 3" and "Word 4" have >> no particular meaning. Just for completeness, can you point me to a >> reference where "pack number" is defined or used by the software? > > Search for DEC standard 144. If nothing else, I think there is a description > in the RL11 documentation. (Me trusting my memory once more...) That's different, though. It describes the bad block table, which includes a pack serial number in its header. Some device types use 144, some do not (in particular, on RP/RM there is a mix -- RP04/5/6 do not, RP07 and RM02/3/5/80 do). The 144 table is purely a software construct, a bit of data placed by convention in the last few sectors of the drive and interpreted by the OS. For example, in RSTS the bad block table is read to mark those blocks as unavailable, and the serial number is read and displayed during formatting but not otherwise used for anything. paul ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
On 2019-06-28 00:59, Rob Doyle wrote: On 6/26/2019 9:54 PM, Lars Brinkhoff wrote: SALV actually writes data for an entire track all in one go. I tried something which skips the headers in the middie. But there must be something else wrong with my code, because when reading back the sector data I just get zeroes. Anway, I agree something like that would go most of the way to make SALV happy. There's another part of SALV that reads the header information go access the pack number written there, but I'm not sure how that number is used later. I think that should work. When executing the "write header plus data" command, the state machine in my FPGA's RP06 controller just handles the first two 36-bit words (technically four 16-bit words) specially and jumps to the "write data only" states to transfer the non-header data. Ditto read and write check commands. Sounds like what I'm advocating. This part of the FPGA passes all of the RP06 diagnostics - so I believe it is correct. That is really interesting to hear. From a hardware point of view, sector header "Word 3" and "Word 4" have no particular meaning. Just for completeness, can you point me to a reference where "pack number" is defined or used by the software? Search for DEC standard 144. If nothing else, I think there is a description in the RL11 documentation. (Me trusting my memory once more...) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
On 6/26/2019 9:54 PM, Lars Brinkhoff wrote: SALV actually writes data for an entire track all in one go. I tried something which skips the headers in the middie. But there must be something else wrong with my code, because when reading back the sector data I just get zeroes. Anway, I agree something like that would go most of the way to make SALV happy. There's another part of SALV that reads the header information go access the pack number written there, but I'm not sure how that number is used later. I think that should work. When executing the "write header plus data" command, the state machine in my FPGA's RP06 controller just handles the first two 36-bit words (technically four 16-bit words) specially and jumps to the "write data only" states to transfer the non-header data. Ditto read and write check commands. This part of the FPGA passes all of the RP06 diagnostics - so I believe it is correct. From a hardware point of view, sector header "Word 3" and "Word 4" have no particular meaning. Just for completeness, can you point me to a reference where "pack number" is defined or used by the software? Rob Doyle ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
Sorry, I did oversimplify it, yes. Essentially, I meant that you should write the data part as a normal write, and ignore the extra fluff required for the write header. That ought to make most software happy. So, skipping extra words intended for the header, adjust size accordingly. Johnny On 2019-06-27 04:05, Bob Supnik wrote: I don't think it's that straightforward. The write header and data command must include the proper Massbus word count for header and data. The Unibus side of the RH11 is doing 18b transfers, and so is the disk side, so the word count ought to be 260 for an RP and 258 for an RM. If the simulator doesn't "skip" the right number of header words, SALV is going to fail on its block data check. /Bob On 6/26/2019 7:37 PM, simh-requ...@trailing-edge.com wrote: I would vote for someone doing just the naive write as a starting point. I think much software will be happy enough with just that, and then we can look at specific when we locate software that really do care about what is written into the headers. Johnny ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
SALV actually writes data for an entire track all in one go. I tried something which skips the headers in the middie. But there must be something else wrong with my code, because when reading back the sector data I just get zeroes. Anway, I agree something like that would go most of the way to make SALV happy. There's another part of SALV that reads the header information go access the pack number written there, but I'm not sure how that number is used later. Bob Supnik wrote: > I don't think it's that straightforward. The write header and data > command must include the proper Massbus word count for header and > data. The Unibus side of the RH11 is doing 18b transfers, and so is > the disk side, so the word count ought to be 260 for an RP and 258 for > an RM. > > If the simulator doesn't "skip" the right number of header words, SALV > is going to fail on its block data check. > > /Bob > > Johnny Billquist wrote: >> I would vote for someone doing just the naive write as a starting >> point. I think much software will be happy enough with just that, >> and then we can look at specific when we locate software that really >> do care about what is written into the headers. ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS, salvager)
I don't think it's that straightforward. The write header and data command must include the proper Massbus word count for header and data. The Unibus side of the RH11 is doing 18b transfers, and so is the disk side, so the word count ought to be 260 for an RP and 258 for an RM. If the simulator doesn't "skip" the right number of header words, SALV is going to fail on its block data check. /Bob On 6/26/2019 7:37 PM, simh-requ...@trailing-edge.com wrote: I would vote for someone doing just the naive write as a starting point. I think much software will be happy enough with just that, and then we can look at specific when we locate software that really do care about what is written into the headers. Johnny ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
Re: [Simh] RP/RM differences in header commands (for ITS salvager)
On 2019-06-26 19:54, Bob Supnik wrote: Implementing a more complete form of read/write/write check header is not as straightforward as I thought, because the RP and RM drives use different header formats. The RP expects 4 16 bit words, of which the first two are used, and the second are "for software". Word 0 is cylinder plus 18b/16b, word 1 is sector, words 2 and 3 are "keywords". The RM expects 2 16 bit words, both used. Word 0 is cylinder plus 18b/16b plus two bad block indicators. Word is 1 is track and sector. The simulator supports the RP06, RP07, RM02/3, RM05, and RM80. I'm not sure if the RP07, RM05, or RM80 were ever actually qualified for the KS10. However, the RP06 and RM02 both shipped with the system, so the 2 word/4 word distinction would have to be implemented. I can't find the sector format for the RP07 which, despite its name, behaved like an RM series drive. The RP07 is actually even more complicated. I wrote a formatter for RSX for it at one point. It was more of a hack than really properly doing the formatting. As far as I remember, for the RP07, you can even specify the gap between sectors, which potentially allows you to map around bad spots on the disk. So there is information about that kind of things in the header as well. I can't remember where I got the RP07 information from back then, but probably the set of microfiches we had. I would vote for someone doing just the naive write as a starting point. I think much software will be happy enough with just that, and then we can look at specific when we locate software that really do care about what is written into the headers. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
[Simh] RP/RM differences in header commands (for ITS salvager)
Implementing a more complete form of read/write/write check header is not as straightforward as I thought, because the RP and RM drives use different header formats. The RP expects 4 16 bit words, of which the first two are used, and the second are "for software". Word 0 is cylinder plus 18b/16b, word 1 is sector, words 2 and 3 are "keywords". The RM expects 2 16 bit words, both used. Word 0 is cylinder plus 18b/16b plus two bad block indicators. Word is 1 is track and sector. The simulator supports the RP06, RP07, RM02/3, RM05, and RM80. I'm not sure if the RP07, RM05, or RM80 were ever actually qualified for the KS10. However, the RP06 and RM02 both shipped with the system, so the 2 word/4 word distinction would have to be implemented. I can't find the sector format for the RP07 which, despite its name, behaved like an RM series drive. /Bob ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
