The "motion vector" displays that were generated for Battlestar Galactica were not done on the 4051. They were done on the Tektronix 4081, which was a very interesting machine. 19" DVST (Direct View Storage Tube) for the display, which had a mode which was called "write-thru" which allowed the beam to run at a reduced intensity which would cause line segments not to 'store'. If the beam was moved around fast enough, you could do moving vectors. The 4081 was based on an OEM'd Interdata 7/16 CPU board. As I recall, the Interdata 7/16 had an IBM 360-like instruction set. It was a 16-bit CPU, made to run with core memory (thus it had a write-sense-rewrite memory cycle). Tektronix designed a specialized display processor, which would share main memory with the CPU, and operated on "display lists". The display processor was fast enough that it could draw vector graphics in write-thru mode fast enough that (if there weren't too many segments) you could do some pretty good animations without flicker. As I recall, the display processor was reasonably smart...allowing a series of vectors to be 'connected' together as an entity, and all that was necessary to move it around was to update the display list parameters that stated the origin of the object, e.g., early sprites. The 4081 CPU cabinet was about the size of one of those small refrigerators that you can put under a desk. The systems booted (IPL'd) off a mag-tape cartridge, the same type as used on the 4051. The 4081 generally came with at least one cartridge disk drive (ala DEC RK05, but made by CDC as I recall) with one fixed, and one removable cartridge platter, each of about 5 Megabytes. There was an operating system for the machine, but I can't remember for the life of me what it was called. Most of the programming was done in a macro assembler, though I think that there was a FORTRAN complier also available for the machine, along with PLOT 10 libraries. Tektronix graphics programmers worked with the producers of the show to generate the vector animation graphics on the 4081. There *was* a modification that some folks did to the 4051 which allowed it to also do write-thru animation, but the only way to get anything useful was to write machine code (4051 BASIC had a means to fill a character string with machine code and execute it) to run the display system. With tightly written code (the 4051 used a Motorola 6800 CPU), it was possible to do some simple animations without too much flicker. I once saw a "space war" style game run on such a modified 4051, and it wasn't bad at all. The later 4052 and 4054 machines, with their biploar implementations of the 6800 instruction set, I believe had a 'write thru' mode to allow vector graphic animation to be done without having to do hardware modifications. I know all of this because I worked at Tektronix at the time, and did a lot of programming on the 4081 and 4051. I remember a big story in 'Tekweek' (Tektronix' internal company newspaper) about Tektronix contributing so heavily to the production of Battlestar Galactica. Not only were a lot of 4051's used, they also used a lot of TM500 modular test equipment on the set. Rick Bensene Tektronix employee - 1977-1990 The Old Calculator Web Museum http://oldcalculatormuseum.com

Ethan, The same guy has a bunch of "Battlestar Galactica" stuff. I wonder if that's what got him interested in the 4051 to begin with? Joe At 01:07 PM 3/28/03 -0800, you wrote: