Hi Bill,
At 02:10 PM 10/13/00 -0500, you wrote:
>Greetings,
>
>I subbed this list because I was given a rather large & heavy old machine
>which the owner refers to as an "Intel MDS225" and I am totally devoid of
>any official information about it. It consists of a large, white, main
>unit, which houses a CRT display, power supply and a bank of slots, several
>of which are occupied by plug-in cards.
Cool! I have one of these too. Mine started out as a 225 but has been
upgraded and modified. I have SOME of the docs for the system and they can
only be called MASSIVE! I have seven 8 1/2 x 11" binders and each one is
about 5" thick. I have several ICE units for it but I don't remember if I
have the docs for them. The standard CPU in these was a 8080 or an 8085
but they could be upgraded to 8088 and I think to an 80186 or 80286. Mine
has the 8088 in it. All the cards in it are a standard type card called
MultiBus. All Multibus are readilty identifable because they all have two
connectors on the bottom edge. One connector has 80 contacts spaced .156"
on center and the other has 60 contacts spaced .100 on center. The standard
card size is 12 x 6.75 inches.
The operating system for these is ISIS (Intel Systtem Implementation
Supervisor). This was later upgraded to ISIS-II. I think that's what I
have on mine but it's been so long since I used it that I'm not sure. They
also have a monitor ROM built into them. PL/M (aka PL/M-80), a Macro
Assembler, BASIC-80, iCIS-Cobol and Fortran-80 were all available for them.
I don't have the specs for the 225 handy but it was a 220 with one
upgrade that I don't recall. I do have the 220 specs; 4 K ROM, 32K RAM
expandable to 64K, Eight level maskable priority interrupts, built in
interfaces for paper tape reader, PT reader/punch, printer and Universal
EPROM programmer. Compaible with standard iSBC expansion modules, integral
CRT with detachable full ASCII keyboard. 250K floppy drive. Standard
Multibus with multi-processor and DMA capabiltiy. 2000 character upper and
lower case display. OH! and a 8080A was the standard CPU. 2.6 MHz CPU
clock speed.
>
>The unit also includes a separate keyboard, and a dual 8" floppy drive
>housed in a cabinet (which is blue in color), and fits underneath the main
>unit.
You should have an 8" floppy drive standing vertically on the right side
of the CRT. The two drives in the separate box were an option. The earliest
ones were mounted vertically in a narrow (relatively!) box. The later ones
were mounted horizontally in a shorter but wider box. The later box is the
same width as the main chassis. The orignal drives were single sided and
I think single density. Mine has been upgraded to Double sided Double
density. The main chassis should have a row of interrupt switchs on the
front of it. There is also a similar box that does not have the interrupt
switchs. That is an optional expansion chassis. I have the separate Intel
EPROM burner and Intel paper tape reader with mine. The EPROM burners are
common in this area but this is the first PT reader that I've seen. I also
found an Intel printer that's made to go with the unit but it was
incomplete so I passed it up.
The best book that I've seen for getting started with these is "A Guide
to Intellec MicroComputer Developement Systems" by Daniel D. McCraken.
McCraken is better known for his PL/M book.
Also supplied is a set of hardware that I believe is for in-circuit
>emulation of an i8048 microprocessor. As I understand it, this machine was
>used to develop firmware for several products which were controlled by 8048
>/ 8749 micros. The owner also said that it runs (or ran, I have not put
>power to it) the ISIS operating system.
>
>So what have I got here, and to what potentially interesting use might I
>put it? Was it worth the agony of dragging it home and up the steps? :)
It's an interesting system but very antiquated! But FWIW I drug mine
home about 12 years ago and it's still here. That's saying a lot
considering how big it is!
Joe
>
>Thanks,
>Bill Layer
>Sales Technician
><b.layer_at_vikingelectronics.com>
>
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Received on Sat Oct 14 2000 - 00:04:06 BST