On 3/13/11 5:27 PM, Zane H. Healy wrote: *sob* -- Dave McGuire Port Charlotte, FL

At 5:34 PM +0000 3/13/11, Tony Duell wrote: That's it! Thanks Tony! Good to know. Zane -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com | OpenVMS Enthusiast | | | Photographer | +----------------------------------+----------------------------+ | My flickr Photostream | | http://www.flickr.com/photos/33848088 at N03/ |

My V80 has a TMS9900 seires procssor in it too, along with some state machines (I think there may be a 2900-series sequencer chip involved) to cotnrol the timing for the signals to the electrodes. On a more genrarl point, why do namy collectors regard old printers/plotters/other peripherals as 'junk' while processorts from the same vintage are 'interesting'? As I've said before, I'm very much a hardware person, and can find interest in all sorts of odd hardware. Yes, procssors are interesting -- of course they are. But to me the motor control logic of, say, an HP7245 printer/plotter is more interesting than many microcomputers. So is the electrode control logic of the V80. -tony

If people are looking to get rid of old plotters or other graphics hardware output devices, please contact me. Computer graphics history is split between displays and print output devices as far as hardware is concerned. Given the engineering context of much early computer graphics, the paper output devices are just as important as the displays. By the time graphics evolves to the consumer entertainment area, people aren't as interested in printed output. (When was the last time you wanted a printed output -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

'Toroublesome and large'... I can think of plenty of classic computers that applies to as well :-) (No flames, please...) Ah no, you misunderstood me. If I seriously wanyt a printout from a classic computer, I am likely tro use a printer somewhat more mdoern than the machine. IF the host classic computer can `print' to an RS232 port, then I'll vcapture the data with something like an HP98LX and transfer it later to this PC [1] for formatting and printing. Of coruse there are machines in my collection that really should be used with the printer/plotter that they were designed to work with, and in that case I do try to restrore and use the 'right' unit. [1] If I ever do get a more modern machine, one thing I would insist on, even more than having full schematicvs, would be an RS232 port and kermit. It can be an RS232 port on the end of a USB converter or whatever, but I have som many devices that use that 'standard' that I would not want to be stuck with a machine that could talk to none of them. Anyway, the main reason I do this is consumables. Printers do use up paper and/or ink (toner, ribbons, inkjet cartridges, sparkjet electrdes, etc), and at least one of those is likely to be hard to obtain for a classic pritner now. No, what I was saying is that I find the old printers and plotters themselves to be interesting in some cases. The motor control circuitry of an HP7245 -- the accumulator registers, adders, sin/cos look-up table ROMs, DACs, analogue filtering, etc -- interests me. The timing stat machine in the Versatec V80 intersts me. The discrte-transisotr interface, DACs and servo amplifers in an HP9125 pkoiter interest me. The state machine controller and shift registers to store a line of characters in the HP9866 interest me. Perhaps not as much as a similar-technology processor/computer system, but I would find repaairing/investigating one of the aforementioned hard copy devices to be a lot more interesting than doing the same to, say, a typicel 1980s home computer. It's the same with other peripehrals too. I find some of the older modems, now totally useless for data communications (even I want something a little faster than 300 bits per second, and I don't have a 4-wire leased line :-)), to be interesting in design. -tony