Vtserver, pdp11/34, and saving images

From: Julian Wolfe <julian at twinax.org> Sent: Aug 8, 2014 7:15 AM To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Vtserver, pdp11/34, and saving images Hi Don, What else have you tested at 115K baud? I'm looking to do the mod myself, and am curious about the drawbacks. Julian On Thu, Aug 7, 2014 at 4:01 PM, Don North <ak6dn at mindspring.com> wrote: > On 8/7/2014 9:00 AM, Henk wrote: > >> On Aug 6, 2014, at 5:45 PM, Roe Peterson <roeapeterson at gmail.com> wrote: >>> >>> Has anyone ever used vtserver to copy a physical pdp11 disk to an image >>> file? >>> I know it is usually used in the other direction, copying an image to a >>> real disk. >>> >>> A local pdp11/34 has popped up, and there are several RK05 packs >>> I desperately want images of. >>> >>> Also, I seem to remember some discussion of a version that could auto >>> boot >>> with the 11/34 console emulator, instead of ODT... >>> >>> As always, thanks for any info. >>> >> >> Maybe I misunderstand the question, but if you have a spare DL11-W >> that you can put in the /34, configure it at 176500 / 300 (IIRC). >> Then the /34 thinks there is a TU58. Get Don North's TU58EM. >> You can boot the /34 from the virtual "TU58" *and* then dump >> (piece by piece) the RK05 to the second attached virtual TU58 tape. >> It's not fast, but it works. >> > > Hey Henk long time ... > > At 9600b (max standard rate of a DL11-W) it is not fast. However, a DL11-W > can > be modded to support 115.2Kb fairly easily (new UART, remove one chip in > baud > divider and replace with a wire, and a new crystal oscillator). I have > done this for > my 11/34 and I can now boot XXDP in about 15 seconds (vs 3 min at 9600b). > > There is at least one bootable RT-11 TU58 image floating around that has > had > the tweak to support 32MB (ie, 16 bit block number) image size, so using > this > image you could copy a real RL02 to a TU58 RL02 sized image directly. At > 115Kb > my math tells me it would take something like 15-20min to transfer a 10MB > image. > An RK05 image (1.5MB IIRC) would be something like 3min. > > Another option, if you have that hardware, is the RX01EMUL board, >> with an M105 and M7821. That connects to a PC parallel port and >> mimics an RX01 floppy drive. >> I have never tried to boot a PDP-11 via RX01EMUL though. >> I *did* boot an 11/34 using TU58EM from a Toshiba "laptop" >> (VHS cassette sized mini PC). Was kinda fun to see a big computer >> boot from such a tiny PC. Nowadays you could use a Raspberry, etc. >> >> > There is a guy who has ported TU58 emulator code to Arduino, uses SD card > for storage: http://www.torok.info/computing/pdp11/tu58/index.htm > > - Henk >> >> >