Computer Replica's

From: Patrick Finnegan <>
Date: Wed Mar 24 22:45:00 2004

On Wednesday 24 March 2004 21:25, Kane, David (DPS) wrote:
> CPUs could have emulated guts, either software or one off hardware
> designs, with replica enclosures and front panels. That feels like it
> would result in a reasonable result for the effort required, but
> mechanical I/O will be the tough bit. I have recently mulled over the
> idea of constructing a PDP-11/04 replica; I imaged a bent metal case,
> a replica programmer's front panel, and an internal PC mother board
> running SIMH would be feasible, but I have shuddered at the thought
> of trying to interface it to 8" floppy drives (if I could find any),
> or building a card reader and line printer.

Interfacing with an 8" floppy drive isn't *necessarily* all that
difficult... unless you want it to be RX01/RX02 format compatible.
I've managed to read/write disks using a cable I made myself using
386-based Compaq Deskpro, under Linux, even! The only issue I had was
that things like fdformat didn't particularly like the missing three
cylinders at the end (77 vs 80). Oh, yeah, you might have an issue if
the drive you're using expects a hi/lo head current signal (track >
35?). You'd have to generate that yourself somehow. I remember seeing
a PIC microcontroller based solution to help with doing that somewhere

Purdue University ITAP/RCS        ---
The Computer Refuge               ---
Received on Wed Mar 24 2004 - 22:45:00 GMT

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