I have been working on CDC CYBER 170 mainframes between 1977 and 1988. In 2002 I wrote an open-source emulator for the CDC 6000 and CYBER series (see my website http://www.control-data.info/). In 2013 I also developed the open-source VHDL firmware emulating the console controller for these systems. The firmware runs on a Xilinx Virtex 6 FPGA on a PCI Express (PCIe) board. The off-the shelf Xilinx board carries a small custom "piggy-back" board with 4 DACs and 4 op-amps to interface to a DD60or CC545 console. This PCIe board was used by Paul Allen's Living Computer Museum (LCM) in Seattle from 2013 onward in a PC running my 6000/CYBER series emulator to drive a real DD60 console. The CC545 has a very similar interface and my emulated controller would work with it too.
For many years I have been trying to find one of these vector drawn CC545 consoles to use with my emulator but I haven't been able to find one. Recently I decided to build a clone of it myself. Bitsavers has a hardware manual with schematics: http://www.bitsavers.org/pdf/cdc/cyber/cyber_170/62952600L_CYBER_170_Display_Station_CC545-CDEF_Hardware_Reference_26Mar1979.pdf The CC545 console achieved unusually fast deflection with an electromagnetically deflected CRT. I am trying to understand the tricks they used to get these high speeds. Part of the magic is a dual-yoke which provided gross positioning within 2 microseconds to anywhere on the screen using the first yoke (this is VERY fast) and then painted the character using a second yoke around that base position with 0.1 microsecond per stroke (this is VERY fast too). The two yokes work in an additive manner. The reason there are two yokes is that you need quite low inductivity/impedance to be able to drive the symbol vectors at 0.1 microsecond per vector with up to 24 vectors making up one character. The gross position yoke needs to create a large enough magnetic field to sweep across the entire screen so has a higher inductivity/impedance but the magnetic field has 2 microseconds to stabilise. The older DD60 console used electrostatic deflection which is much faster by its very nature. Traditional CRT oscilloscopes were all electrostatically deflected because of the speed advantage over electromagnetic deflection. The CC545 manual on Bitsavers has a good description of the circuits and schematics, but unfortunately Section 8 with the "Parts Data" has not been scanned. I really would like to know the types of transistors used in the 4 deflection amplifiers as well as the details of the dual-yoke and possibly the CRT data. It would also be very useful to see details of the design of the dual-yoke and possibly the inductivity of each of the coils. This dual-yoke is most unusual and very different from what is used in TVs, CRT monitors and even vector drawn games like Vectrex or early vector drawn Atari arcade games. Could somebody please help? Thanks Tom Hunter
