On Wed, Jan 23, 2019 at 8:41 PM Allison Parent via cctalk <cctalk@classiccmp.org> wrote: > On Jan 23, 2019, at 8:43 PM, Paul Koning via cctalk <cctalk@classiccmp.org> > wrote: > > On Jan 23, 2019, at 5:37 PM, Noel Chiappa via cctalk > > <cctalk@classiccmp.org> wrote: > > > > http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/PDP-11_Models.html > > > A variant of the LSI-11 is the H-11 sold by Heathkit. Is that actually the > same board? Either way it would be worth mentioning
I have an H11 and it has a real DEC CPU board. The backplane is Heath, with industry-standard (not DEC's zig-zag) backplane edge connectors, and Heath parallel and serial cards, but the CPU card is 100% DEC. > The heath h11 and the lsi11 are > The same right down to the handle. The prime difference > Is the heath backplane is smaller number of slots and user assembled along > with the case and power supply. The memory, io, and disk system > was all heath and could be used in dec backplanes and DEC cards in heath. > The heath disk was RX01 comparable and could format media. Right. The H-27 disk system definitely worked with RX01 media and could format blank media. I have an H-27 that came with my H-11 but the former owner (my boss at the time) never used the H-27 and I never got it working to boot from it. My boss did a massive case mod to extend the width of the box several inches and made a simple 2-slot CD-interconnect (two Heath backplane connectors and some wire) so he could fit in an RLV11. That's how I used it at work, and when the company closed and he gave me the old box, I undid the mod (it was functional but not strong and definitely not pretty) and so now I can't use the RLV11 in there any more (yes I have an RLV12 now). The point here being, we didn't use the H-27 and I never got it working to boot from it. All I ever had for this box was real DEC RT-11 (v5.4). I never got the original HT-11 disks, so if the H-27 needs a special RT-11 driver, that's likely where I'm getting stuck. > Do you want to show the PRO system boards? And maybe the I/O boards? Those > both are quite different looking, especially the I/O boards with their odd > connector and differing number scheme. (PRO boards are marked with the ROM > ID number, a 16-bit value shown in 6 octal digits.) Yep. Many's the time I "fixed" a PRO by unclamping and reclamping the backplane connector on all the boards. -ethan
