RE: DEC KM11 (Was: DEC KL11)
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Tony Duell > via cctalk > Sent: Friday, September 24, 2021 4:12 AM > To: Noel Chiappa; General Discussion: On-Topic and Off-Topic Posts > Subject: Re: DEC KM11 (Was: DEC KL11) > > On Thu, Sep 23, 2021 at 6:38 PM Noel Chiappa via cctalk > wrote: > > > Huh? The KM11 doesn't plug into the UNIBUS (or QBUS); it's a MASSBUS device > > (a > > solid-state storage device, actually), so it plugs into an RH11 or RH70 or > > something like that. (I should work with the VAX MASSBUS controller, too.) > > So the question 'is it 18 bit compatible' makes no sense. > > Were there 2 things called the KM11? > > The KM11 that I know is the maintenance unit, composed of a W130 and > W131 plugged together. It goes into a specially-wired connector on > some older PDP11s (e.g. the 11/45), controllers (e.g. RK11C) and > periperals (e.g. RX01). > > I have a pair of real DEC ones, and a clone I built to do tests on my > PDP11/45 before I got the DEC ones. > > -tony I think that we're all talking about the ML11-A, or at least are intending to ... although the Subject line has been erroneous from the get-go ... As Mark said: PartTitleStatus EK-0ML11-TD *ML11 Technical Description EK-0ML11-TM *ML11 Technical Manual EK-0ML11-UG *ML11 User's Guide - paul
Re: DEC KM11 (Was: DEC KL11)
On Thu, Sep 23, 2021 at 6:38 PM Noel Chiappa via cctalk wrote: > Huh? The KM11 doesn't plug into the UNIBUS (or QBUS); it's a MASSBUS device (a > solid-state storage device, actually), so it plugs into an RH11 or RH70 or > something like that. (I should work with the VAX MASSBUS controller, too.) > So the question 'is it 18 bit compatible' makes no sense. Were there 2 things called the KM11? The KM11 that I know is the maintenance unit, composed of a W130 and W131 plugged together. It goes into a specially-wired connector on some older PDP11s (e.g. the 11/45), controllers (e.g. RK11C) and periperals (e.g. RX01). I have a pair of real DEC ones, and a clone I built to do tests on my PDP11/45 before I got the DEC ones. -tony
Re: DEC KM11 (Was: DEC KL11)
My notes (from sources unknown) say (of the ML11A): solid-state (ram) disk; 2MB/s xfer 1-31 arrays of 512 or 2048 blocks ea using 11/70 MK11 (MOS) memory looked like RS03/RS04 to s/w Ok, that makes sense. http://gunkies.org/wiki/RS03/04_disk_drive says about *REAL* RS03/04 drives: "basic format was 18-bit words (for use in PDP-10 and PDP-15 machines)" But I doubt that anyone would care to replicate THAT feature (throwing away two bits of each word) on a PDP-11 option! Well, that would otherwise have been used for Massbus parity. The number of bits on the drive stayed the same, it's just that the formatter would either format the disk for 512 or 576, then use the top two bits either for parity or the last 2 data bits. The other fun question that I have to figure out is can an RM80 be run in 18 bit mode. I'm guessing it can as it uses the same Massbus formatter as the RM02/03/05. Need to roll that thing out of my son's closet when he moves out and see what happens... C
Re: DEC KM11 (Was: DEC KL11)
> But the sector format is a different matter. If it's designed for > PDP-11 and friends, presumably it has a 512 byte sector size. > For PDP-10 or -20 use you'd presumably want a sector size consisting > of some round number of 36 bit words. 576 byte sectors (128 words), IIRC. The unit of allocation on TOPS-20 was a page (512 words). I forget what it was on TOPS-10: 256 word blocks? My notes (from sources unknown) say (of the ML11A): solid-state (ram) disk; 2MB/s xfer 1-31 arrays of 512 or 2048 blocks ea using 11/70 MK11 (MOS) memory looked like RS03/RS04 to s/w http://gunkies.org/wiki/RS03/04_disk_drive says about *REAL* RS03/04 drives: "basic format was 18-bit words (for use in PDP-10 and PDP-15 machines)" But I doubt that anyone would care to replicate THAT feature (throwing away two bits of each word) on a PDP-11 option!
Re: DEC KM11 (Was: DEC KL11)
> From: Paul Koning > But the sector format is a different matter. If it's designed for > PDP-11 and friends, presumably it has a 512 byte sector size. For > PDP-10 or -20 use you'd presumably want a sector size consisting of > some round number of 36 bit words. Actually, the -10/-20 MASSBUS situation is even more complicated than that. The MASSBUS can operate in 16 or 18 bit data width (for everyone else; this is totally different from the Q16/Q18/Q22 of the QBUS, which is _address_ width), so it can support 36-bit words directly, using two extra data lines. So for the RP04 and other disks, and their 'controllers' (at least, the part that's in the device), they have to be able to turn the bit-stream from the mass storage device into 18-bit wide words. (And they actually have different sector formats depending on whether they are in 16- or 18-bit mode.) What the KM11 does, I don't know (I'm too lazy to go look at the TM); I would not at all be suprised to find that it can _only_ operate in 16-bit mode (i.e. the array of memory chips is 16 bits wide, and it just ships a line at a time from that out in parallel, so there's no way to even produce 18-bit wide words). The name of the device (KM11) adds weight to that supposition. Noel
Re: DEC KM11 (Was: DEC KL11)
> On Sep 23, 2021, at 1:38 PM, Noel Chiappa via cctalk > wrote: > >> So I can't say whether they are 18 bit compatible. > > Huh? The KM11 doesn't plug into the UNIBUS (or QBUS); it's a MASSBUS device (a > solid-state storage device, actually), so it plugs into an RH11 or RH70 or > something like that. (I should work with the VAX MASSBUS controller, too.) > So the question 'is it 18 bit compatible' makes no sense. The addressing wouldn't be a question because the Massbus controller handles that. But the sector format is a different matter. If it's designed for PDP-11 and friends, presumably it has a 512 byte sector size. For PDP-10 or -20 use you'd presumably want a sector size consisting of some round number of 36 bit words. paul
