conon Laser Beam Printer LBP8

[Tony Duell]

> 
> > Years ago I was given a broken LBP8-A1 -- the formatter board had a dead
> > PAL on it. As I think I mentioned before, I removed the formatter board
> > and converted it into a CX-VDO printer (no intenral formatter, the
> > interface connector goes straight to the print engine) for my PERQ. I
> > still have the ROMs from the formatter board if you're crazy enough to
> > want to covnert an HP Laserjet (origianl version) into an LBP8-A1.
> 
>     Tony, did you wrote something about that in a site before? Got the 
> adress on hand? 

I am almost sure I mentioned it on this list in the last year. I would 
guess serrchingthe archives for 'PERQ' would find it.

I am not sure what you want to know. I can talk you through taking the CX 
engine apart, and what the 'DC contorller board' -- the print engine 
cotnroller with a 7811 microcontroller and a gate array that controls the 
laser intensity does. And how the various PSUs, laser scanner, etc work.

When I was doing this conversion, you seem I had the printer totally 
apart. And I mean 'totally' I completely stripped down the optical parts 
and had a pile of mirrors and cylindrical lenses at one point (yes, I did 
get it all aligned again)

As regards the actual conversion, the important bit is trivial. A CX-VDO 
has a DC37-S interface connector. It's a straight-through ribbon cable 
from that to the first 32 pins of the 34 pin header on the DC controller 
board. The last 2 pins on that connector go to an earth tag on the 
connector bracket.

I didn't bother with (and never found out the ocnnections of) the 
mini-DIN connectoer for some kind of exeternal paper feed. The PERQ never 
supported that, I don't have one, etc.

There's a 6 pin header on the DC controller board that's unused in the 
LBP8. It carres the status LED signals (ready, paper out, etc). I 
dismantled the original control panel from the LBP8 (and added a 7 
segment display, switches, etc to the junk box), and used 5 of its LEDs 
and the associated resistors on the origianl PCB. I made a new trim panel 
for it (not the right layout for an CX-VDO, since I used the old PCB and 
plastic housing from the LBP8, but that doesn't matter) and soldred a 
length of ribbon cable to the PCB which ends in a sockt to fit said header.

Let me know what you're trying to do and I can probably help.

-tony