DF32x4 (was Re: 8/L repairs)

From: Ethan Dicks <erd_6502_at_yahoo.com>
Date: Fri Mar 28 15:40:00 2003

--- Charles <charlesmorris_at_direcway.com> wrote:
> >B) Would you write up where you attached your pullups?
>
> Check the schematic, it was on the preset lines to the 7474
> containing stop bit 1 and stop bit 2...

That's good enough to find it. Thanks.

> >Are you using a microprocessor on your DF32x4? FPGAs? PALs? TTL?
>
> Plain old 74LS and a Dallas Semi DS1258 128kx16 NVRAM.

Interesting. Can't wait to see the plans.

> >How are you handling the cabling issue?
>
> Cables :)

:-) indeed.

> (I also laid out a PCB to plug in the backplane and accept a
> standard 40 pin IDC header connector). Had five fabricated and
> made 3 foot ribbon cables.

Sounds great. If several folks wanted to get into a bulk-buy, we
could probably get a stack of those cheap. I was getting 12" long
boards with inches of gold fingers (GG2 Bus+ - 100-pin Zorro plus
16-bit ISA) for well under $20 each, q 100., with silk screen and
solder mask. Panelled out, something like this could be as cheap
as a few bucks each in sufficient quantity.

No matter what the device (external memory, external disk, etc.),
I'd *love* to have a stack of inexpensive paddle cards to interconnect
a variety of devices I have. Another bonus is that the modern
end of the cable does *not* have to resort to hard-to-find DEC-style
slots and fingers. 40-pin IDC stuff is about as cheap as it gets.

Also, it might be interesting to experiment with them as a base for
simple prototype modules (I keep kicking around an idea for a
crystal-controlled M452 replacement for higher-than-110-baud use
on an M706/M707 set) - just attach the "device" to the 40-pin
spot and go.

I could probably put dozens of these to use in the first few months,
all by myself. I would probably even be willing to act as a point-of
contact on a group order. The more the merrier.

> > Do you have a way to load
> >the emulated disk devices "out of band"? (i.e., can you get data into
> >it in any way other than the databreak interface to the -8?)
>
> No, I took the DF32 manual and copied the specs as closely as
> possible. The 8/L should "think" it has a real DF32 and three
> expansion DS32's attached.

Well... that's easy to build, anyway. I suppose it would be easy enough
to make a parallel-port NVRAM programmer...

> >What's the picture of?
>
> Pic is of the DF32x4 on the workbench. I'll send you a copy
> direct.

Thanks,

-ethan
Received on Fri Mar 28 2003 - 15:40:00 GMT