Category: ECS Microsystems 4500

The Input Output board that was originally in the unit did not have PIO so it has been replaced with the spare card.  This may allow the use of a parallel port printer.

Ports from left to right looking from the rear:

25 Pin Female D	Daisy Chain Serial Port on RS232 Buffer board.  Do not use.
25 Pin Male D	Serial Port on RS232 Buffer Board.  This sis connected to the 8251 on the Microcomputer Board.  This port is the terminal connection for dumb terminal built into the monitor ROM and initiated with “t” at the monitor prompt.  9600, 8 bits, no parity.  A null modem was required to connect to a PC.
25 Pin Female D	Serial Port on Datacon board.  This board is connected to the SIO on the Input Output Board.  Level shifting is done on the Input Output Board.  2400, 7 bits, odd parity.  May be configured as the printer port.
25 Pin Female D	Parallel Port on Intercon Board.  This is different from the original configuration which used a Concat Board. The Intercon Board is connected to PIO Port A on the Input Output Board.  This may work with a parallel printer but without success so far.

System configuration is important to make these devices work.

The DIP switches on the I/O Board may have an effect.  There is some info in the manuals, but it is patchy.

Virginal system disks seem to be absent so it is necessary to construct a couple based on my best guess of what was on them.

There seem to be two main categories of operating system: 64k and FAST.  There are different versions of both. The FAST (File Access Storage & Transfer) uses the addition 32k above 64k to improve performance, eg by providing disk buffering.

The Checklist in the documentation is quite specific about the FAST files, so a disk has been prepared based on that list.  RUN.COM could not be found.

The 64k version described in the manuals is version 8.3, but the coverage is not comprehensive.  The constructed system disk is my best guess based on what is usually on a CP/M 2.2 disk.  There are three different formatting programs.

Fresh disk images were created using a pair of goteks.  This was mainly done for the FAST 2.22 operating system.  A clean OS disk was created and the used as seed for various other disks including basic, wordstar, dbase etc.  This was done using a pair of goteks running flashfloppy.

The new disks worked fine both as images and when written to floppy media, but it was not clear what speed flashfloppy would use for writing disks.  Looking at the images in the HxC software it seemed that it was writing at 281rpm sometimes.

Just to be completely safe the images were written to floppy media on the machine and then re-imaged at 285rpm.  These disks are numbered starting at 101.

A disk index is here: