I've made some progress on this topic since my original post and the short answer is yes, you can run RT-11 on the H11. The WH-27 drives have some enhancements over real RX02s - in particular, the WH-27s can format diskettes (!!!) - and there's a switch on the front of the WH-27 for "Enhanced Mode" or "RX-01" mode. HT-11 (the Heath crippled version of RT-11) will only boot if the switch is set to "extended" (if you try to boot with it set to "RX-01", HT-11 tells you to change the switch and reboot!). I think Ethan asked how Heath/Digital prevented users from running HT-11 on a real PDP-11; I'd assume this is the way. If you set the switch to "RX-01" then you can boot real RT-11 (at least V4 and V5 - I've tried both) _provided_ that your diskette is a RX01. "RX-01" mode really means RX01, not RX02. But if you have a bootable single density RX01 floppy with the system handler set to the DX device, it will boot. My only mistake was that I was trying to boot RX02 media. This is doubly annoying because the WH-27 is double density capable, but only in "extended" mode. In fact, you can boot HT-11 (again, in "extended" mode) and do a directory listing of a double density RT-11 RX02 diskette, but you can't boot it in "RX-01" mode. Of course, the LSI-11/2 has no memory management so you can't run the XM monitor, but that's to be expected. Actually, I want to do something similar to Ethan's old boss, except that I plan to add a hard disk by using a Dilog DI-602 card. It attaches to a standard MFM disk and emulates a RL02 controller and, best of all, it's only a double module. It'll fit the backplane easily. The only problem is that the boot ROMs, which are on the WH-27 card, don't know how to boot a RL02. Any ideas? Bob -----Original Message----- From: ed sharpe [mailto:esharpe@uswest.net] Sent: Sunday, July 25, 2004 5:38 PM To: bob(a)jfcl.com; General Discussion: On-Topic Posts Only Subject: Re: Booting real RT11 on a Heath H-11 we will be watching this thread but please CC us on any discussing on this as we will soon be firing up our H 11... and yea it has the heath drives... I thought I saw some copies of rt 11 that were in the boxes that did not look heathkit specific but do not know if the guy ever got them running. ed sharpe archivist for smecc ----- Original Message ----- From: "Robert Armstrong" <bob(a)jfcl.com> To: <cctalk(a)classiccmp.org> Sent: Thursday, July 22, 2004 10:24 PM Subject: Booting real RT11 on a Heath H-11

On Sun, Jul 25, 2004 at 08:24:06PM -0700, Robert Armstrong wrote: I have something similar, a DQ-614 I pulled from a DataRAM Qbus box. What my boss did was to pull the floppy controller and use a BDV-11 bootstrap/terminator. It has the DL boot on it. -ethan -- Ethan Dicks, A-130-S Current South Pole Weather at 26-Jul-2004 08:00 Z South Pole Station PSC 468 Box 400 Temp -94.0 F (-70.0 C) Windchill -137.8 F (-94.3 C) APO AP 96598 Wind 11.6 kts Grid 080 Barometer 656.3 mb (11532. ft) Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html

Jerome Fine replies: There are probably two simple options: (a) First boot the DX floppy which contains a DL.SYS device driver, then BOOT DL: While this method takes a bit longer than (b) below, at least you can see what you are doing. (b) A bit more direct is to copy the software boot block from block zero of the RL02 to block zero of the RX01 floppy. This will then complete the boot operation from the RL02 media. I would strongly suggest that you do this with a separate RX01 media which you use just for this purpose. By the way, Megan Gentry suggested this a while back. It is certainly a useful method to quickly substitute one boot hardware for another when the boot ROMs do not have the choice you want to use. Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.