-----Original Message----- From: Megan [mailto:mbg@world.std.com] Sent: Tuesday, November 09, 1999 10:24 PM To: Discussion re-collecting of classic computers Subject: Re: RT11 V5.7 + RA92 = ? Okay, as one of the developers involved with RT-11 at the time the DU handler was first developed after we actually got some prototype MSCP controllers, I have to respond... At the time we got the controllers, the primary address had already been defined, but the secondary and subsequent addresses were assumed to be allocated out of the floating CSR and floating vector areas. It wasn't until some later time that it was decided that the secondary and subsequent addresses were to be fixed and had a certain algorithm for determining. By that time, SYSGEN had already been modified. It was decided that 1) for backwards compatibility and 2) since the addresses can be changed with SET CSRn and VECn, SYSGEN wouldn't be changed. We didn't ignore the defaults, there were none at the time to ignore. Finally, there is the problem of the SBC-11/21[+], where the 'standard' MSCP address is actually in a pre-allocated area, so it has to be located elsewhere (176150)... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+