Opinions and theories about the 3 ADAM Slots

[Captain Cozmos]

Please, everyone's thoughts

I am not trying to pretend I know everything, my specialty is in software engineering.

So going over the schematics and a multi-meter in an attempt to understand the three internal slots, am I wrong to conclude that they are all connected and basically the same thing?

Sure a couple of them are missing a few lines but in theory you should be able to put a memory card in any one of those slots.

The middle slot has the most lines but again, they should all be the same.
At a minimum they all have address and data lines, 5+ and ground.

 

So what is to keep you from using RAM or ROM in any one of those slots as long as you maintain the rules?  Mind that the pins may be in different locations.
As far as using the center slot for higher memory thanks to the refresh line.

 

Again, I am trying to understand because I am now getting into that territory for the DOS project.

Thank you for your time.

CC

[adamcon]

2 hours ago, Captain Cozmos said:

Please, everyone's thoughts

I am not trying to pretend I know everything, my specialty is in software engineering.

So going over the schematics and a multi-meter in an attempt to understand the three internal slots, am I wrong to conclude that they are all connected and basically the same thing?

Sure a couple of them are missing a few lines but in theory you should be able to put a memory card in any one of those slots.

The middle slot has the most lines but again, they should all be the same.
At a minimum they all have address and data lines, 5+ and ground.

 

So what is to keep you from using RAM or ROM in any one of those slots as long as you maintain the rules?  Mind that the pins may be in different locations.
As far as using the center slot for higher memory thanks to the refresh line.

 

Again, I am trying to understand because I am now getting into that territory for the DOS project.

Thank you for your time.

CC

Your thoughts are valid; the answers vague.  Coleco intended at a minimum that ADAM could support a serial modem in slot 1, I believe a language card in slot 2, and a memory card in slot 3.  They also used the external expansion on the side for the Auto Answer device.  When orphaned and others charged onto the scene, they made larger memory expanders, serial modems, printer cards and all the rest.  Basically, almost anything a developer wanted, the ADAM "could" provide in one form or other.  Trysid made a slot 1 serial 1200 baud modem; MI made mem expanders for slot 3, ide cards for slot 1 & one for slot 2, and powermate hd's using slot 2 - w/ or w/out printer support etc.  HLM/GMK did serial on the side port, 80 col video.  and on and on.  You just need to think outside the ADAM box and use whatever slot you need to and keep in mind what else might use that slot and conflict.  IF you think it, you CAN do it!!! 

[Captain Cozmos]

I have been thinking along those lines but have you heard of anyone creating a memory card in the center slot?

Or how about multiple devices on each slot.

Again, if all three share the same data and address lines then what sets each apart that makes them special in the sense of addressing that slot.
Which pin says I am slot 1, slot 2 and slot 3?  There has to be some unique identifier as to which one is which or else you could make a card riser and put 4 devices on the center slot as thought experiment.

If I had to make an assumption it would be that put many devices on those address lines and assign a port number that only the device knows and will answer when talked to.
 

[Falonn]

1 hour ago, Captain Cozmos said:

... if all three share the same data and address lines then what sets each apart that makes them special in the sense of addressing that slot.

I've never seen or touched an Adam--so there is a much higher chance that I'm mistaken--but if these are the three card slots from the schematic that you're talking about, it looks like the pinouts are quite different:

 

 

Picking a pin at random, let's say 28, the three slots are routed to BA7, BD7, and BA12.  CAS2 comes in on pin 5 of the RAM/ROM slot, pin 19 of the I/O slot, and not at all on the RTC slot.  They all look very different.  So it would probably make sense to make a particular card for a particular slot.  Trying to make something that worked in any/all three would take a lot of extra work, glue logic/buffers, and something like a jumper to pick between them.  It would be easier (and cheaper because of fewer components) to just make alternate PCBs for the different slots you wanted to support (assuming they've even got the signals you need available to them; that RTC slot is missing a lot).

[adamcon]

2 hours ago, Captain Cozmos said:

I have been thinking along those lines but have you heard of anyone creating a memory card in the center slot?

Or how about multiple devices on each slot.

Again, if all three share the same data and address lines then what sets each apart that makes them special in the sense of addressing that slot.
Which pin says I am slot 1, slot 2 and slot 3?  There has to be some unique identifier as to which one is which or else you could make a card riser and put 4 devices on the center slot as thought experiment.

If I had to make an assumption it would be that put many devices on those address lines and assign a port number that only the device knows and will answer when talked to.
 

I know that slot 2 can support parallel printer w boot prom, or print card with hd pinout, or I believe the Powermate uses center to access hd/floppy unit

[Captain Cozmos]

1 hour ago, Falonn said:

I've never seen or touched an Adam--so there is a much higher chance that I'm mistaken--but if these are the three card slots from the schematic that you're talking about, it looks like the pinouts are quite different:

 

 

Picking a pin at random, let's say 28, the three slots are routed to BA7, BD7, and BA12.  CAS2 comes in on pin 5 of the RAM/ROM slot, pin 19 of the I/O slot, and not at all on the RTC slot.  They all look very different.  So it would probably make sense to make a particular card for a particular slot.  Trying to make something that worked in any/all three would take a lot of extra work, glue logic/buffers, and something like a jumper to pick between them.  It would be easier (and cheaper because of fewer components) to just make alternate PCBs for the different slots you wanted to support (assuming they've even got the signals you need available to them; that RTC slot is missing a lot).

I understand that the pins are in different locations but I believe that all the lines with the same name are the same line.
If I would have designed the ADAM it would have 3 slots exactly the same without the nonsense.  There is obviously room for it.
I remember there was a break out box that connects to the expansion port so however that was designed.

There are only so many data and address lines in an 8 bit computer.

The difference in ADAM's case is that the video chip has it's crap connect to it's own ram.

So, if I were to make a RAM card to work in the center slot all that would mean is that I can not use the center slot for something else unless it was all on one card.

[NIAD]

Unfortunately, the three Internal Expansion Slots were all setup differently as you know instead of identical like the Apple II internal slots and other computers. I can only assume that this was done for a number of reasons:

 

- Cost savings

- trace layout space on the ADAM Logic Board

- making each Slot very specific for the required function

- ADAMnet, ADAMnet, ADAMnet... almost everything was planned to work thru ADAMnet and daisy chain, even Serial and Parallel Interface(s) and a Hard Drive which were all prototyped.

 

When the external ADAMnet 1200 Baud Modem was scrapped due to cost saving, Slot #1 was dedicated to DCE devices (Modems). Slot #2 was always set for a Boot Prom/Language Card and Slot #3 was set for a 128K Memory Expander (no memory addressor needed in Slot #2) and numerous In-House ADAMs had these installed, but Coleco again went the cheaper route with the 64K ME... was supposed to come in a plastic housing but ended up as just the PCB.

 

The breakout box that you mention for the External Expansion Bus was the EVE Electronics VD-MB 80 Column Unit.

 

 

EVE Electronics - VD-MB 80 Column Expansion Unit - Info.pdf

[allansim]

I have a 300 baud modem that fits into a slot.  I can't contribute much, but for a wishlist it'd be nice to have cards for each slot that could do all the important stuff, like 80-columns with VGA output, ADE or FujiNET, expanded memory module + enhanced sound (not sure if that last one is possible or if it can only be done on the side slot).

[Captain Cozmos]

15 minutes ago, allansim said:

I have a 300 baud modem that fits into a slot.  I can't contribute much, but for a wishlist it'd be nice to have cards for each slot that could do all the important stuff, like 80-columns with VGA output, ADE or FujiNET, expanded memory module + enhanced sound (not sure if that last one is possible or if it can only be done on the side slot).

Working on it.

[NIAD]

16 hours ago, allansim said:

I have a 300 baud modem that fits into a slot.  I can't contribute much, but for a wishlist it'd be nice to have cards for each slot that could do all the important stuff, like 80-columns with VGA output, ADE or FujiNET, expanded memory module + enhanced sound (not sure if that last one is possible or if it can only be done on the side slot).

It was pretty much all done in the 80/90s, but those hardware add-ons are pretty scarce. So, the likes of Bob & Doug Slopsema, Sean Myers, Eric Pearson and John Lundy have recreated all those old hardware add-one over the last 10 years and everything is still available to purchase:

 

ann.hollowdreams.com

 

lundyelectronics.com

 

fujinet.online

 

If you want a near complete list of everything, check out my hardware list for the Coleco ADAM Computer. It’s only a text list, but by the weekend, I should have a big update completed with PICTURES!!!

 

http://adamarchive.org/archive/

 

and looking forward to what Captain Cosmos and Charles Mouse come up with in the future as well as the ADAM+ by DVDH.

Edited December 20, 2022 by NIAD

[Captain Cozmos]

12 minutes ago, NIAD said:

It was pretty much all done in the 80/90s, but those hardware add-ons are pretty scarce. So, the likes of Bob & Doug Slopsema, Sean Myers, Eric Pearson and John Lundy have recreated all those old hardware add-one over the last 10 years and everything is still available to purchase:

 

ann.hollowdreams.com

 

lundyelectronics.com

 

fujinet.online

 

If you want a near complete list of everything, check out my hardware list for the Coleco ADAM Computer. It’s only a text list, but by the weekend, I should have a big update completed with PICTURES!!!

 

http://adamarchive.org/archive/

 

and looking forward to what Captain Cosmos and Charles Mouse come up with in the future as well as the ADAM+ by DVDH.

I have something cooking on the burner.
If I can pull it off it will bring a new dimension to the Coleco ADAM and retain compatibility.
 

[RGDiRocco]

On 12/19/2022 at 2:49 PM, adamcon said:

Your thoughts are valid; the answers vague.  Coleco intended at a minimum that ADAM could support a serial modem in slot 1, I believe a language card in slot 2, and a memory card in slot 3.  They also used the external expansion on the side for the Auto Answer device.  When orphaned and others charged onto the scene, they made larger memory expanders, serial modems, printer cards and all the rest.  Basically, almost anything a developer wanted, the ADAM "could" provide in one form or other.  Trysid made a slot 1 serial 1200 baud modem; MI made mem expanders for slot 3, ide cards for slot 1 & one for slot 2, and powermate hd's using slot 2 - w/ or w/out printer support etc.  HLM/GMK did serial on the side port, 80 col video.  and on and on.  You just need to think outside the ADAM box and use whatever slot you need to and keep in mind what else might use that slot and conflict.  IF you think it, you CAN do it!!! 

 

[Captain Cozmos]

My theory is that the Middle Slot is all you need for anything you want to do.

If you need a hardware expansion that takes over the whole system then you use the external expansion port.

[NIAD]

5 hours ago, Captain Cozmos said:

My theory is that the Middle Slot is all you need for anything you want to do.

It gets pretty interesting routing the two Serial and 1 Parallel cables from the MIB3 installed in Slot #2 especially if one also has an IDE Interface with cable in Slot #1 and two Data Drives and their cabling to deal with installed.

 

The only problem with an all-in-one solution interface for Slot #2 is that there will be a lot of people that won't need all of the functionality of such an interface card, especially one or two serial ports, and therefore those people would have been forced to pay much more for capabilities that they would never use. However, for people that would use the full functionality of such an interface, it would end up being cheaper to purchase just this one interface compared to three individual interfaces for each of the interface slots.

 

My biggest concern with an all in one solution would be if the interface malfunctioned then all the capabilities of the interface would be lost until it could be fixed or replaced.