ICD Multi I/O Video Port Information

[bbking67]

i had heard that the Multi I/O was originally supposed to ship with a video port. I'm not sure if that meant a monochrome composite style port like the XEP80, and RGB like the ST or a TTL like the IBM, but I'm pretty certain it was originally going to include video--specifically 80 column video of some sort. I'm assuming getting rid of the feature was cost cutting measure as well.

 

Does anyone have additional information about the video port? Did any prototypes get released with video?

 

Personally I always wanted a high quality 80 column capability for the 800XL... I did buy the XEP80 (and it was okay, not great but did work), but would have love a parallel bus 80 column adapter.

 

Here is the quote from the manual:

80 Column Video Interface

The MIO has a video port on its front left side. This is for use with an optional 80 column adapter which plugs on top of the MIO circuit board. The pin assignments are listed in the 80 Column Adapter Users Manual.

I'm assuming that the adapter never got made?

[TXG/MNX]

yes if someone could build some would be cool

[+bob1200xl]

A few 80-column adapters got made. I've never tried this one but I was told that it works OK. I think ICD didn't want to compete with the XEP-80.

 

A nicer way to do this is to use the 6545 video chip. It accesses memory during the first half of the clock cycle, interleaving with the CPU.

 

As with many things, the hardware is not so difficult - the software is the major issue.

 

Bob

[+bob1200xl]

Oops...

 

MIO 80-column adapter:

 

[+Larry]

Neat! But again, vastly larger than I expected. This was to go inside the MIO case?

 

According to Tom Harker (many years ago) the firmware was already written -- they simply made a business decision not to produce the unit (since by that time, the Atari market was in decline). If so, it might exist somewhere. (?)

 

-Larry

[+Stephen]

Oops...

 

MIO 80-column adapter:

 

DSC01362.JPG

How do you have all this cool stuff?

[bbking67]

Wow... does it work? How is the performance? What type of monitor is it made to drive?

[+David_P]

Looking at the board, there's 2x 2K SRAM, a SMC9007 video display IC (http://www.bg-electronics.de/datenblaetter/Schaltkreise/CRT9007.pdf) - I found them on eBay for about $10 each - and an EPROM that presumably contains the OS driver. The rest looks like switching and latching logic (plus a PAL).

 

Looks like it's ready to go - or ready for someone to make copies and start selling...

[gozar]

My Mio has the header for the 80 column card, but if I remember correctly, it's really close to the edge, I don't think that card would fit in the case. But maybe I'm remembering it wrong. :-)

[re-atari]

Oops...

 

MIO 80-column adapter:

 

DSC01362.JPG

I see 1 major obstacle standing in the way of rebuilding the hardware, besides an obsolete videochip, in the form of a PAL logic array. Finding out what it does in order to reverse engineer will be challenging, if it's even possible. If the security fuse is burned you cannot read its contents like an eprom.

Another complication is that PALs were gradually replaced by GALs some 25 years ago. PAL sourcecode needs to be adapted to GAL source before you can assemble and burn it in a GAL. IIRC a program called PAL2GAL was the tool to do the conversion.

 

re-atari

[HiassofT]

I see 1 major obstacle standing in the way of rebuilding the hardware, besides an obsolete videochip, in the form of a PAL logic array. Finding out what it does in order to reverse engineer will be challenging, if it's even possible. If the security fuse is burned you cannot read its contents like an eprom.

Another complication is that PALs were gradually replaced by GALs some 25 years ago. PAL sourcecode needs to be adapted to GAL source before you can assemble and burn it in a GAL. IIRC a program called PAL2GAL was the tool to do the conversion.

Actually it's not that bad as you may think.

 

If you can read out the logic, just run the .jed file through JED2EQN and you have the logic terms.

 

Even if the security fuse is blown it's not too complicated. The PAL 16L8 is a pure combinatorial chip, no (hidden) registers or state machines are involved - it's just a (not too) big and/or array.

 

From the schematics you should be able to figure out how the 6 I/O pins are used, the rest of the pins are fixed inputs and outputs. Then you just have to apply all input combinations and check the output pins - for example using a small adapter and an EPROM programmer. With this information you can either re-create the original logic or just program it into an EPROM (if the output enable feature isn't used, otherwise you might have high-Z outputs and/or bidirectional IO pins).

 

so long,

 

Hias

[+bob1200xl]

Yes, well, actually, I did the Atari PAL many years ago by hand. The fuse map is available - you just write down the connections. Once you have a CUPL file for the 16L8, you just tell the compiler to compile a 16V8 GAL as a 16L8 PAL. Works fine.

 

I would be inclined to use a CPLD and throw most of the other logic in it, also. All you need is one SRAM, an EPROM, a CPLD, and the video chip.

 

I got this one from Mike Hohman way back when. He said it worked fine - I don't remember if we actually ran it or not. I do remember that you need a different EPROM on your main MIO board. I think it drives a composite monitor - mono, for sure.

 

Bob

[+bob1200xl]

How do you have all this cool stuff?

 

I kept everything I was given, bought stuff from Atari employees, Atari users, and Atari dealers. Having Atari 'just down the street' was a big advantage.

 

Bob

[bbking67]

I think it drives a composite monitor - mono, for sure.

 

 

I just pulled out my MIO and it has a DB9 for the Video (mine is populated--I think some later productions might not be). Thing is, a DB9 seems like overkill for composite, so that's why I always thought it might be TTL or even RGB.

 

Funny, I took out the MIO just now to look at the port... my original receipt dated June 11, 1987 was in there and I paid $300 for the MIO (I'm in canada and prices are higher here). Then there was a torn customs slip from a repair I had done a couple of years later than cost me $164.95.

Edited August 4, 2014 by bbking67

[+bob1200xl]

My sticker says "Composite - pins 2 and 7". Whether other pins have other outputs, I do not know.

 

The MIO main code should be 1.42b, I think.

 

Here is an 80-column card plugged into an MIO. You can get the cover on, but may balk at considering "it fits".

 

Bob

 

[bbking67]

What is the 50 pin header for?

[+Stephen]

My sticker says "Composite - pins 2 and 7". Whether other pins have other outputs, I do not know.

 

The MIO main code should be 1.42b, I think.

 

Here is an 80-column card plugged into an MIO. You can get the cover on, but may balk at considering "it fits".

 

Bob

 

DSC01363.JPG

So cool. I just remembered, I have 5 of those CRT 9007 ICs.

[+David_P]

What is the 50 pin header for?

 

I think that's the SCSI port.

 

Looking at my MIO, a Rev 2 board, the headers to accept the video card aren't populated

[BillC]

 

I just pulled out my MIO and it has a DB9 for the Video (mine is populated--I think some later productions might not be). Thing is, a DB9 seems like overkill for composite, so that's why I always thought it might be TTL or even RGB.

 

Funny, I took out the MIO just now to look at the port... my original receipt dated June 11, 1987 was in there and I paid $300 for the MIO (I'm in canada and prices are higher here). Then there was a torn customs slip from a repair I had done a couple of years later than cost me $164.95.

I'm surprised you still have the video port! When mine went in for repair, the usual diode issues, ICD also removed the video port, the unused headers(J5/J7/J10) and some power circuitry(C42/C43/D1/D6/VR2). They also changed the end panels to perforated instead of solid.

 

Although I can't remember what year it was, I'm pretty sure the repair was after they had already decided not to make the 80-column upgrade. Especially with the removal of the 3 headers to connect to it and the video port.

[+Stephen]

I'll have to take mine apart and see if anything is there for video. I am doubtful - as it has the perforated end panels.

[bbking67]

Mine has the solid end panels... maybe that's why my memory fried... I ran a BBS, so it was 24x7. When my MIO died I actually bought another one so I could keep going... I eventually sold that one to the NCAUG Atari group (Ottawa Canada users group) to run their BBS. The port is there... I recall that the other unit I had did not have the port (I'm assuming it had the perforated sides, but I can't remember). Mine was bought June 11, 1987, so I would think that it was manufactured early in 2007. The unit was abnnounced at the Winter Consumer Electronics show in January and released shortly thereafter, so my guess is that only the very first run still had the port.

 

In the original Antic article from April 1987, you can see the unit with the video port intact (its the one closest to the front of the case right beside the DB9 for RS232.)

 

http://www.atarimagazines.com/v5n12/ICD.html

https://groups.google.com/forum/#!topic/comp.sys.atari.8bit/MCqBahoXOjw

[BillC]

Mine has the solid end panels... maybe that's why my memory fried... I ran a BBS, so it was 24x7. When my MIO died I actually bought another one so I could keep going... I eventually sold that one to the NCAUG Atari group (Ottawa Canada users group) to run their BBS. The port is there... I recall that the other unit I had did not have the port (I'm assuming it had the perforated sides, but I can't remember). Mine was bought June 11, 1987, so I would think that it was manufactured early in 2007. The unit was abnnounced at the Winter Consumer Electronics show in January and released shortly thereafter, so my guess is that only the very first run still had the port.

 

In the original Antic article from April 1987, you can see the unit with the video port intact (its the one closest to the front of the case right beside the DB9 for RS232.)

 

http://www.atarimagazines.com/v5n12/ICD.html

https://groups.google.com/forum/#!topic/comp.sys.atari.8bit/MCqBahoXOjw

I doubt ICD removed the video port/headers until after they decided not to make the 80-column upgrade.

In addition to my original 1MB MIO I also have a slightly later, going by serial#, 256KB model that I acquired a couple of years ago as part of a large bundle, which still has the solid end panels and DB9 video port.

[fibrewire]

Here is another one with the video port.

 

http://www.shopgoodwill.com/auctions/Vintage-Atari-ST-Computer-Accessories-17664113.html

[bbking67]

wow that is an awesome lot!

[+MrFish]

On 8/3/2014 at 7:58 PM, bob1200xl said:

I got this one from Mike Hohman way back when. He said it worked fine - I don't remember if we actually ran it or not. I do remember that you need a different EPROM on your main MIO board. I think it drives a composite monitor - mono, for sure.

 

On 8/3/2014 at 9:16 PM, bob1200xl said:

The MIO main code should be 1.42b, I think.

 

 

Hi Bob,

 

Do you have the ROM necessary to run the video card? If you do, would you consider dumping it for preservation purposes?

 

Thanks,

MF

 

Edited April 17, 2020 by MrFish