RL02 to PC image

Ethan Dicks ethan.dicks at gmail.com
Fri Dec 15 13:22:13 CST 2017


On Fri, Dec 15, 2017 at 1:49 PM, systems_glitch
<systems.glitch at gmail.com> wrote:
> It's on my list of things to do -- you can run external clock into DL11 and
> DLV11-J style connectors, and IM6402 UARTs are supposed to go up to 2 mbit,
> so somewhere between 38400 and 2 mbit should be possible.

Good to know the IM6402s will go that fast.

> I believe it'll
> require external RS-232 transceivers due to the design of the ones used on
> various DEC boards.

Yeah... that's kinda why I was thinking of hacking a DLV11J or
DL11-W... I have a number of each of those and have no problems making
multiple changes for the purposes of media slurping.  They are common
boards and hacking 1-2 of them isn't going to increase scarcity.

A side-effect of modding the DLV11J could be high-speed TU58 emulation...

> Figure if I can get any real improvement out of it, I'll lay
> out a board and provide high-speed kits.

I'm available for any experimentation, etc.  I have plenty of
mid-range PDP-11 hardware for this sort of experimentation.

> Anyone know of a 40-pin UART with a FIFO? :)

I do not, but it would have to be a transparent FIFO - that was one of
the problems with the 8250/16550 was the host code had to know about
the FIFO, so the 16550 worked fine as a 8250 but also supported the
16-byte FIFO that drastically cut interrupt overhead.  I do not know
of any material enhancements to the IM6402 in any subsequent chips.

-ethan


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