Jerome Fine replies: While using the paddleboard is definitely the most convenient way to run a VT103, it is also completely unnecessary. So while I would pay a reasonable sum to buy a paddleboard if I was going to use a VT103 in a commercial way - or if I was into restoring a VT103, I might even build my own paddleboard so as to run the VT103 in the normal manner, for anyone who just wishes to run a VT103 and have fun, then the use of a paddle board is not required. The primary purpose of the paddleboard was to allow the VT100 portion of the VT103 to be directly connected to the console port of a DLV11-J (4 serial port SLU) and for the normal DB25 connection to be used to attach a serial line printer. Internally, one of the other ports on the DLV11-J could then be attached to the slowest "disk drive" ever, the TU-58. On one occasion back over 10 years ago, a friend was demonstrating how long it took to boot RT-11. Well, after 2 minutes, we were about to go for coffee when it finally finished. Without the paddleboard, it is necessary to use a cable to run the use of the VT100 portion as the console device. Then, in addition, a serial line printer must be attached to other port via a cable which then goes to the printer. One notable aspect of the paddleboard (if I remember correctly - if necessary either Megan or I can check for you if you have the paddleboard) is that the baud rate on the DLV11-J is left to float for both the console and printer port and the paddleboard sets the baud rate for the console port at 9600 baud and the user via the SETUP commands is able to set the baud rate for the serial line printer port. As far as I know, all DEC versions of the VT103 came with an 18 bit backplane for the QBus. If an LSI-11/03 is used, I understand it may be ill advised to make any changes in the backplane, as well as fruitless, since this CPU can use only a maximum of 56 KBytes of memory in any case. However, both the 11/23 and the 11/73 CPUs are able to use all 4 MBytes of memory with the primary OSs for the PDP-11. However, I have also heard that the use of a quad CPU with a 22 bit backplane may also risk damage to the CPU in the VT103 environment. BUT, I have seen both the dual 11/23 (M8186) and the dual 11/73 (M8192) used with an upgraded 22 bit backplane within the VT103 along with a full 4 MBytes of memory. In addition, there was a DLV11-J and a third party hard disk controller, a Sigma RQD11-B (an MFM interface - which also had BOOT ROMs for the MSCP device) along with a 5 1/14" hard disk drive situated under the tube. The disk drive happened to be a Micropolis 1325 of 70 MBytes. And while I would strongly recommend against running with a DHV11 for any extended period of time due to the lack of a proper power supply on the VT103 (and especially in that case, placing the hard disk drive on an external power source - a PC power supply does very nicely), that can also be done for short demonstrations of up to an hour if it seems desirable. What is very sad is that DEC had all this software and most of the hardware available back in 1980 and Ken Olsen, along with the senior VPs at DEC, decided that the PC market was not where DEC wanted to be focused - namely high volume and low unit profits. The VT103 was, already in 1980 with the 11/23, and shortly thereafter with the 11/73, a far better PC than the MS-DOS/Intel combination could produce until the 486 was released in 1989. All that was necessary back in 1980 was a decision to compete in the PC market - a decision that IBM also refused to make as well. If anyone has a VT103 and needs some help with how to set it up as well to convert to a 22 bit backplane, likely both Megan Gentry and I are able to supply the necessary technical information. Sincerely yours, Jerome Fine RT-11/TSX-PLUS User/Addict Year 2000 Solutions for Legacy RT-11 Applications (Sources not always required)

On Tue, 18 Aug 1998, Zane H. Healy wrote: Besides the VT103 name plate on the front, how else can I tell that I'm looking at a VT103, or perhaps a VT100 with a Qbus backplane? Are there any tell tale signs on the back of the unit? Sam Alternate e-mail: dastar(a)siconic.com ------------------------------------------------------------------------------- Ever onward. September 26 & 27...Vintage Computer Festival 2.0 See http://www.siconic.com/vcf for details! [Last web site update: 08/09/98]

On Tue, 18 Aug 1998, Bill/Carolyn Pechter wrote: What power supply type would I look for? Sam Alternate e-mail: dastar(a)siconic.com ------------------------------------------------------------------------------- Ever onward. September 26 & 27...Vintage Computer Festival 2.0 See http://www.siconic.com/vcf for details! [Last web site update: 08/09/98]

Jerome Fine replies: We never said it was... the question was originally whether one could attach the VT100 to a serial line directly. I responded "yes" and went on to describe the hardware which was designed to help do it for you... two minutes? that is slow... I can boot my TU-58 based system in 30 seconds... (I engineered an optimized TU58 many years ago when people within Digital were asking how to get it to boot faster). It involves specific placement of various RT-11 files on one of the four recording tracks. For those who wanted the system to run faster once booted, you could additionally take the step of loading stuff into VM and rebooting it it... That is absolutely correct... (depending on the rev of the 11/23... only Rev.C could do so). 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 | +--------------------------------+-------------------------------------+