IMSAI Progress

From: Dave Dameron <ddameron_at_earthlink.net>
Date: Thu Jul 22 20:28:44 1999

At 07:30 PM 7/22/99 -0400, Bill wrote:
>Well, I gave up on the MIO for a while. Tony's explanation,
>while good, was making my head spin! Also, I don't have any
>26 pin card edge connectors. So I started looking at the
>Cromemco 4FDC documentation and, lo-and-behold, it has a
>serial port. The documentation on the serial port is clear
>and simple, and I now have toggled in a short program to
>initialize it and echo characters (also, put them on the
>front panel lights). According to the docs, the EPROM on this
>board contains a monitor which operates through the serial
>port, but, and it is quite emphatic about this, it is Z80
>code. Is anybody out there using one of these? With an
>8080A? Maybe could send me an alternate monitor to burn
>on an EPROM?
>
Yes I have used the 1k "RDOS" monitor, one thing that made it useful was
the source printed in their brown booklet. Back when, I modified it to use
a Vector Graphics flashwriter. You might look for earlier Cromemco monitors
that could use a 8080A. (Like with a 8k Bytesaver). If you aren't using a
disk, the 3 most useful cammands are display memory, substitute memory, and
jump to a location.
I don't remember if any of these in the RDOS monitor would work with a
8080, but they aren't too difficult to program. That monitor source is how
I "got my feet wet" with Z-80 assembly.
I also have Cromemco "Control basic" somewhere in 3 2708's, but could not
get it to run several years ago, either with a TUART or fixed serial port.
(bit rot?)

-Dave
Received on Thu Jul 22 1999 - 20:28:44 BST