VC404 The Standard

From: Lawrence Walker <lwalker_at_mail.interlog.com>
Date: Thu Jul 16 22:47:25 1998

> >
> > One of my recent curbside finds is a machine put out by a Canadian company
> > based in Waterloo Ont called Volker-Craig model vg-400. On the front it has a
> > title VC404 The Standard. It has a k-b attached with ribbon cable which is
> > about the size of a C64 with Function Pf1-12 buttons as well as a separate
> > pod with APL,PAGE,FULL,LOCAL on the left vertically. There is a full
> > qwerty alphabet and numerical pad as well as some specialized keys the most
> > unusual of which is a key labelled "rub-out" and no down arrow. In the back it
> > has a 25 pin RS232 connector, a BNC labelled "composite video" ,2 switches :
>
> Are you sure it's a BNC connector? All the ones I've seen have an SO239 (what
> we call an UHF connector) here.
>
 My terminology is undoubtably wrong. I went thru my old Electro Sonic
catalogue and it is listed as an Amphenol 83 series UHF RF connector. It has
threads as opposed to the BNC horizontal pin.
 
> > one 3-pos.to configure parity the other "Transparent on off" It also has
> > cutouts for parallell and serial (maybe a 9pin dshell for different modems)
> > I haven't opened it up yet, and I must admit to doing what the impeccable
> > Tony Duell would deem unforgiveable (sorry Tony, Couldn't he'p m'se'f)
>
> You are forgiven :-).
>
> > I plugged it in and tuned it on. It worked except for a stuck k-b which
> > stopped printing to screen when I punched another key than local on the
> > right-most pad.
> > Obviosly a terminal of some sort, but the keypads are not what I would expect.
> > My guess is it's a terminal for the deaf which hooked up to a service. But why
> > all the other k-b functions. Any ideas ?
>
> {FX : ARD searching through a large bookcase}
>
> I have here the VC414/VC415 technical manual, amazingly. Yes, I know you
> have a VC404, but read on.
>
> It's a standard ASCII terminal, but it can take some interesing options.
>
> First pull the case (2 screws on the back). Inside, there's a
> PSU/backplane in the bottom. Looking from the rear, there's a little
> board towards the right linked to the CRT. On the left there are 2
> vertical larger PCBs.
>
> Now, the difference between a VC404 and a VC414 is those 2 boards. The
> 404 is entirely hardwired TTL, I think. The 414 uses a 6800
> microprocessor. The 404 could be upgraded into a 414 by replacing those 2
> boards. So the first thing to do is to remove those boards and look at them.
>
 This is like a guided tour :^)) Exactly as you describe. The boards are
interestingly laid out and labelled with a horizontal matrix 1-10 and a
vertically ascending A-G with the chips lined up. The first board has a large
chip at B-6,7,8 a GI logo(?) AY-5 1013A and 7928. On the second there is a
motorola chip at F-9,10 MR8701 SCM37734P 7947 and a mini switch-bank
1-8 with the first 4 REV, 50 ,LINE ,FLASH.
> I have scheamtics for the backplane, monitor, assorted keyboards and the
> VC414 boards. I don't have the VC404 board schematics, alas.
>
> Now for the most interesting option. That APL key selects (or can select,
> given the right character generator kludgeboard) a second character set
> for APL. You know, all those strange symbols. I _think_ they replace the
> upper case letters. I didn't realise that was available on the VC404.
>
> The VC414 was made in a number of versions to emulate various terminals,
> depending on the ROMs on the CPU board. I guess the VC404 isn't like
> that, though.
>
> There were various keyboards made. I've got info on the KB4410, KB5301,
> KB4408, KB4412, KB5201, and a microprocessor (8048 controlled) keyboard.
> Do you see any of those numbers on your keyboard?
>
 Yes it has the KB4412 G3.
> You may need a square (Robertson?) screwdriver to take the keyboard
> apart. I did....
>
> -tony
>
 Well, it looks like I'm going to have to read up on terminals. I really know
little about them. It has baud rate settings on the back 300 - 19.2 . I'm
surprised at the speed. I would have thought 2400 or at most 9600.
 Thanks for the help.

ciao larry
lwalker_at_interlog.com
Received on Thu Jul 16 1998 - 22:47:25 BST