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1088XEL Alternative Mother-Board Project

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When there will be no room for rapidus or VBXE it can be ehm full ATX board! There are very cool PC gaming Thermaltake or Coolermaster cases etc...

Prices are almost same. But yes you will need more space in your room. But on other hand we can have neons and feeling that it is huge computer so

more powerful than small one :D.

 

For example this one Thermaltake Chaser A31 Thunder mid-tower chassis:

http://www.thermaltakeusa.com/Chassis/Mid_Tower_/Chaser/C_00001961/Chaser_A31_Thunder_Edition/design.htm

 

Is beautiful. And in color of Atari Basic (READY) screen...

 

main.jpg

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This is quite an ambitious project, as it stands now, even as it has been streamlined, there is going to be quite a bit on the board, already, with the main standard hardware and the most commonly accepted and used upgrades. It's a full motherboard!I think Michael's philosophy, in keeping it to an Open DIY project, at first and his choice of what to include on-board and allowing a straightforward way to piggy-back already-produced add-ons for technical novices, like myself are probably a good way to go about it. ;)

 

Likewise, if it were to go to a production run, (I and I expect most of us don't have the skill or are feeling too confident / inclined to roll our own - maybe in the 10's?) , in order to have enough people sign on, costs need to be kept to not too terrible. Everyone has a slightly different take on what is essential. People don't want to pay for something they may not use. I have no idea what this would cost or how many might need to sign on to make it cost effective, but I expect it might cost as much as a modern modest PC, so...yeah, it needs to be accessible.

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Here's some back-of-envelope calculations on cost. Wikipedia says Mini-ITX is 17 x 17 cm or 6.7 x 6.7 inches. That's 44.89 square inches (SI). OSH Park (http://docs.oshpark.com/services) has two options for a 4 layer board:

 

Prototype: $10/SI for three boards: so 44.89 SI x $10/SI = $448.90 for three boards

Medium Run: $2/SI, 150 SI minimum: so 44.89 SI x 4 boards = 179.86 SI (150 SI minimum) x $2/SI = $359.12 for four boards

 

The medium run is cheaper but takes longer (3-4 weeks vs. 2-3 weeks for prototypes).

 

I've only ever made small boards, so the price is a little alarming, but that's not gonna stop me. Any other suggestions for PCB fabricators, or is this as good as it gets?

Edited by Smokeless Joe

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So, maybe it might work out to something like this. This is just an easy-chair, non-techy assessment, with no real knowledge of these things, but it feels right. ;)

 

- < $100 USD for a bare board

- $200-250 USD for a partially populated board, including all of the needed support circuitry for the included upgrades,(U1MB, U/AV), excluding the proprietary Atari chips, but having sockets so most people may source and install their own. Probably the sweet-spot for most.

- 300+ for a fully populated board, including all proprietary Atari chips...POKEY, CPU , etc. Something for the more enthusiastic people, like myself.

 

(I have no real idea.)

 

If you want to add a VBBXE or Rapidus daughterboard, the price goes up a bit. ;)

 

Might get enough backers to make this doable.

Edited by Standard User

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300Euro for Apple 2 GS or Amiga 600 like computer with 65c816 / 20MHz, 1MB ram, 8channels stereo pokey, SNES like vbxe graphics, sd card, ps/2 key and mouse interface is good price. With New GUI OS it will be amazing 16 bit. And games will looks like on PC engine:

Edited by Matej

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It looks like I need to clarify some stuff before this gets too far off tangent, and people start freaking out. OSH Park is not a place to have large boards made. Their batch processing of multiple people's orders onto a single panel is only cost effective if your board is relatively small, which is not the case with the 1088XEL. And to compound this even more, my design will absolutely be done as a 4-layer board, so OSH Park's price would be astronomical. Good news is that I have found a Chinese company that will produce this board in batches as small as 5 pieces, and for very reasonable cost. What will be the price? I'll hold off on posting that until I am ready to submit my design. No sense in doing so before then. BTW, I think 'Standard User' is closer to reality but still a bit high on the bare board cost.

 

As I've mentioned, I will not be selling either an assembled or unassembled board myself. But I will be providing all of the PCB design files, Gerber's, schematics, BOM, and vendor source listing so that anyone that chooses to either build a few of these for themselves or to sell to others may do so. So just to be clear, I am not taking any orders.

 

There will be no need to go to an ATX sized board to have plug-in Rapidus, VBXE, or Sophia functionality. However to make sure I get this right, I do need the dimensional footprint data for Rapidus and VBXE which Lotharek has not provided to me when I made a request on his contact page recently. Sophia (GTIA on CPLD project) will not be a problem, since I have one of those on the way to me. So if anyone can provide me with dimensions for Rapidus and VBXE that would be super, but keep in mind that I need more than just the footprint dimensions, I also need to know where the 40-pin piggyback socket resides within the footprint.

 

- Michael

Edited by mytekcontrols
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If you run out of room you could consider increasing the board size, mini-BTX increases the PCB size to 203mm x 170mm

 

37650f2c_7dfa8c70_mini-itxmini-dtxmicroa

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wtf...... sorry I just couldn't wrap my head around using osh park for much of anything that isn't tiny...... I can't even consider why anyone would price things out thru them....

I better re read this.....

phew.... thank God! Mikes got it sorted already!

I must need coffee or tea or something....

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I didn't mean to cause any trouble with my OSH post! I priced things out through them because I didn't know any better. I've only ever used them and all my previous projects have been very small.

 

I'm very glad to hear there are other, more cost effective, places available for PCB fabrication.

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I didn't mean to cause any trouble with my OSH post! I priced things out through them because I didn't know any better. I've only ever used them and all my previous projects have been very small.

 

I'm very glad to hear there are other, more cost effective, places available for PCB fabrication.

 

No problem, and no I wasn't thinking that you were trying to cause trouble, but I did feel the need to jump in to let people know that I wouldn't be going this route on this project.

 

Best regards :)

 

- Michael

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VBXE will need a video jack... preferably DIN13 with stereo audio on the ST audio out and audio in pins.

 

I found this to reduce the footprint requirements for the separate S-Video and Composite video connectors from Arihav Electronic Supply (Israel)...

 

s-l500.jpg

 

They have 1200+ in stock and also sell through eBay (Quantity of 3 for $3.95 w/$2.59 shipping).

 

So now I think I can squeeze one of these in...

 

s-l400.jpg

 

ST Monitor Jack Pin-Out Specifications

 

AnZkdbc.png

 

- Michael

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VBXE will need a video jack... preferably DIN13 with stereo audio on the ST audio out and audio in pins.

 

FJC since you likely have experience with this (and suggested the DIN 13 connector), what are the DIN 13 connections required for VBXE to drive into a SC1224 ST Monitor?

 

I've checked the forum, found a few threads concerning this, with one guy making a board with a sync separator on it, that he failed to say whether it actually worked correctly or not, and then in others there is talk about simply using CSYNC derived from GTIA feeding both the VSYNC and HSYNC lines, and yet another guy saying just to route GTIA CSYNC to the ST Monitor's CSYNC input only. Very confusing indeed :ponder:

 

- Michael

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If anyone wishes to see Rapidus and VBXE compatibility I still need the following dimensional data for each board...

 

VBXE Top View (XE Model Version 2.x)

5I7bWjt.png

 

Rapidus Top View (XE Model)

 

d9EcWDK.png

 

Thanks to anyone that can supply this information :)

 

- Michael

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OK: here's a link to the ST monitor pinout:

 

http://info-coach.fr/atari/hardware/interfaces.php

 

The VBXE wiring scheme Candle suggested and which I followed is - as best I can draw it - as follows:

 

post-21964-0-08124600-1485954887_thumb.png

 

This is looking down on at the connector footprint on the motherboard (usually drilled out after the ground layer has been Dremelled off where the RF Mod used to be). Not sure if it's better to put L Aud out on pin 1 for the sake of compatibility with ST monitor cables, nor can I recall exactly what was suggested there: I've been going with the method described in the graphic. ST monitor cables (SCART, at least) often have 75 ohm termination resistors on them which aren't needed with VBXE, so you're always better off with a custom cable regardless. With a DB9 monitor (1084S, etc), (stereo) audio is broken out onto RCA jacks. The beauty of the DIN13 is that there are more than enough signals for video and audio. Also, with a standardised pinout (which might as well closely follow the ST wiring), I don't have to request or construct a video cable conforming to some proprietary pinout every time I work on a VBXE machine someone sends in. :)

 

Check out the VBXE installation docs, of course, on Lotharek's website for details of where the wires on the other side of the jack go.

 

As for board dimensions: I have no scientific measuring tools here, but perhaps someone can offer a second opinion on the following measurements:

 

VBXE
DIA 3mm
A 3.25mm
B 60mm
C 4mm
L 66.5mm
W 49mm
Rapidus:
DIA 2mm
L 89mm
W 51mm
A 4.5mm
B 3.5mm
D 4mm
C 27.5mm
E 3.5mm
F 16.5mm
Can't get to my XE VBXE boards right now in order to measure the adapter offsets, but perhaps Lotharek can offer more exact figures anyway if approached.
Edited by flashjazzcat
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If anyone wishes to see Rapidus and VBXE compatibility I still need the following dimensional data for each board...

 

VBXE Top View (XE Model Version 2.x)

5I7bWjt.png

 

Rapidus Top View (XE Model)

 

d9EcWDK.png

 

Thanks to anyone that can supply this information :)

 

- Michael

I can get you the dimensions on the VBXE board after work tonight. I have a nice Mitutoyo caliper which can do US and metric.

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OK: here's a link to the ST monitor pinout:

 

http://info-coach.fr/atari/hardware/interfaces.php

 

The VBXE wiring scheme Candle suggested and which I followed is - as best I can draw it - as follows:

 

attachicon.gifVBXE DIN13.png

 

This is looking down on at the connector footprint on the motherboard (usually drilled out after the ground layer has been Dremelled off where the RF Mod used to be). Not sure if it's better to put L Aud out on pin 1 for the sake of compatibility with ST monitor cables, nor can I recall exactly what was suggested there: I've been going with the method described in the graphic. ST monitor cables (SCART, at least) often have 75 ohm termination resistors on them which aren't needed with VBXE, so you're always better off with a custom cable regardless. With a DB9 monitor (1084S, etc), (stereo) audio is broken out onto RCA jacks. The beauty of the DIN13 is that there are more than enough signals for video and audio. Also, with a standardised pinout (which might as well closely follow the ST wiring), I don't have to request or construct a video cable conforming to some proprietary pinout every time I work on a VBXE machine someone sends in. :)

 

Check out the VBXE installation docs, of course, on Lotharek's website for details of where the wires on the other side of the jack go.

 

As for board dimensions: I have no scientific measuring tools here, but perhaps someone can offer a second opinion on the following measurements:

 

VBXE
DIA 3mm
A 3.25mm
B 60mm
C 4mm
L 66.5mm
W 49mm
Rapidus:
DIA 2mm
L 89mm
W 51mm
A 4.5mm
B 3.5mm
D 4mm
C 27.5mm
E 3.5mm
F 16.5mm
Can't get to my XE VBXE boards right now in order to measure the adapter offsets, but perhaps Lotharek can offer more exact figures anyway if approached.

 

 

Hi Jon thank you so much for all of this great info :)

 

I'll put the video pin-out data to use immediately, since I am currently creating a DIN 13 connector component in my lay-out software (also found a good dimensional drawing spec in a data sheet to go by). And the Rapidus/VBXE dimensions you gave me will get me very much in the ballpark to confirm my placement and clearances required around the CPU and GTIA. Of course at some point I will need to nail down very precise measurements of the mounting hole locations in relation to at least one pin that plugs into either the CPU (Rapidus) or GTIA (VBXE). I already sent Lotharek an email last week requesting this same information, but have yet to hear from him (busy guy?), hence the posting here looking for this same information.

 

The best solution is for the person that has the original PCB design files (Lotharek), to export the hole locations as a DXF (or DWG) file for the hole locations only. This of course would be ideal, since that file would automatically convey scaled dimensional information which I could directly import into my lay-out, thus giving me 100% accuracy. Although a person with a set of digital calipers could gather this data off of a 'real' board and come quite close to what I need, and because I also intend to build in a little forgiveness by making the mounting holes slightly bigger than required, this should suffice.

 

Note: The mounting holes will be used to allow stand-off placement between the upgrade boards and my motherboard to insure a stable and firm installation.

 

 

I can get you the dimensions on the VBXE board after work tonight. I have a nice Mitutoyo caliper which can do US and metric.

 

Hi Stephen :)

 

That would be fantastic! Thank you very much for offering to do this.

 

- Michael

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Correction: Instead of referring to GTIA for the VBXE to plug into, I meant to say ANTIC instead (I keep confusing this with the SOPHIA video upgrade which does plug into GTIA).

 

Sorry :(

 

- Michael

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Updated PCB Component Lay-Out (allowing room for various upgrade boards)...

 

fLf35Lk.png

 

Sophia will piggy-back GTIA and extend towards the right corner. Only one video enhancement board will fit (either VBXE or SOPHIA). What possible reason would you want both :?

 

Inclusion of the DIN 13 RGB/VGA/YPbPr video jack necessitated the removal of the 'standard' SIO connector (something had to go), leaving us with the DA15 substitute. Access to the video output pins is provided by a ribbon style header that will match pin-for-pin with SOPHIA's on-board connector. The VBXE will require termination via a Dupont connector housing and crimp terminals. Stereo will be directly routed to the appropriate pins on the DIN 13 as has been discussed. The stereo connections will be switched out when using the external 3.5mm jack.

 

PBI connectors are now shown as latched vertical 50-pin IDC headers.

 

I also plan on including the required PAL circuitry on-board, thus eliminating the plug-in daughter board as originally planned. For NTSC systems the extra components can be left off (the clock oscillator will be socketed for switching from NTSC to PAL frequency).

 

The cartridge port will require a small secondary board connected with a ribbon cable to the on-board IDC style connector and then mounted where accessible from the outside.

 

I haven't updated the PCB component for the stacked S-Video Mini-DIN/Composite RCA combo, but it's footprint will be the same side-to-side, with only it's tail extending farther into the board area.

 

- Michael

 

Note: Still need more exact measurements for the Rapidus and VBXE boards.

Edited by mytekcontrols
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mother trucker! anybody wanna print sio ports.... we already have the 3d print sio plugs with shells! :)

Edited by _The Doctor__

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mother trucker! anybody wanna print sio ports.... we already have the 3d print sio plugs with shells! :)

 

IMHO I don't think the lack of a stock SIO style port is really that big of a deal, since you can still plug-in stuff through an adapter cable (one standard SIO cable + two DA15 connectors makes two adapters). Once you connect to a disk drive, you automatically have a stock SIO connector to use for plugging in anything else via the daisy-chain.

 

- Michael

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Updated PCB Component Lay-Out (allowing room for various upgrade boards)...

 

fLf35Lk.png

 

Sophia will piggy-back GTIA and extend towards the right corner. Only one video enhancement board will fit (either VBXE or SOPHIA). What possible reason would you want both :?

 

Inclusion of the DIN 13 RGB/VGA/YPbPr video jack necessitated the removal of the 'standard' SIO connector (something had to go), leaving us with the DA15 substitute. Access to the video output pins is provided by a ribbon style header that will match pin-for-pin with SOPHIA's on-board connector. The VBXE will require termination via a Dupont connector housing and crimp terminals. Stereo will be directly routed to the appropriate pins on the DIN 13 as has been discussed. The stereo connections will be switched out when using the external 3.5mm jack.

 

PBI connectors are now shown as latched vertical 50-pin IDC headers.

 

I also plan on including the required PAL circuitry on-board, thus eliminating the plug-in daughter board as originally planned. For NTSC systems the extra components can be left off (the clock oscillator will be socketed for switching from NTSC to PAL frequency).

 

The cartridge port will require a small secondary board connected with a ribbon cable to the on-board IDC style connector and then mounted where accessible from the outside.

 

I haven't updated the PCB component for the stacked S-Video Mini-DIN/Composite RCA combo, but it's footprint will be the same side-to-side, with only it's tail extending farther into the board area.

 

- Michael

 

Note: Still need more exact measurements for the Rapidus and VBXE boards.

 

One thing I noticed about the placement of the PBI slot 1 and the power connector is that they are exactly in line. That could be a source of conflict. Power cables tend to be thick and harder to bend. PBI cards are most likely going to need external access, which means in most cases will need to extend to the rear edge of the board. That would place a card directly over the power connector. If you look at the mini-itx form factor, you'll see that the power connector is a little off-set. I'm not sure what the two other connectors are, but you may also run into like problems.

 

Sadly, I don't see a lot of options. It's really tight quarters. :(

 

The only thing that might work is IF the controls/connectors etc could be fitted to a slot cover and connected via a cable to the PBI card itself.

Edited by Dropcheck

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If anyone wishes to see Rapidus and VBXE compatibility I still need the following dimensional data for each board...

 

VBXE Top View (XE Model Version 2.x)

5I7bWjt.png

 

Thanks to anyone that can supply this information :)

 

- Michael

Grrrrr. Sorry - my tools and VBXE boards are 2 floors down in the basement and the family is all sleeping. I'll get the stuff in the morning and take measurements for you then. Work can wait :)

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One thing I noticed about the placement of the PBI slot 1 and the power connector is that they are exactly in line. That could be a source of conflict. Power cables tend to be thick and harder to bend. PBI cards are most likely going to need external access, which means in most cases will need to extend to the rear edge of the board. That would place a card directly over the power connector. If you look at the mini-itx form factor, you'll see that the power connector is a little off-set. I'm not sure what the two other connectors are, but you may also run into like problems.

 

Sadly, I don't see a lot of options. It's really tight quarters. :(

 

The only thing that might work is IF the controls/connectors etc could be fitted to a slot cover and connected via a cable to the PBI card itself.

 

Yep you are absolutely right about the tight quarters and running out of options because of it :)

 

To be honest the PBI set-up in this design really lends itself best to devices that also have a ribbon cable attachment, which would allow some flexibility in placement, and in some cases might even be routed external to the enclosure. My aim was really at providing something that could be put inside a small PC case, or even a custom enclosure. Using the Mini-ITX form factor allows for a lot of options in this area, since it's mounting holes are a subset of an ATX motherboard, and hence may be utilized in a larger ATX enclosure if desired. This of course opens up all sorts of possible mounting locations and external access to things. Of course now days a PBI device can be made very small, and doesn't necessarily need to take up much room, and whatever stuff does need to be connected to it (or plugged in, like an SD card) can have a bracket mounted ribbon connected port located away from the PBI board itself which I believe is what you were suggesting (similar to how its been done for certain PC expansion boards in the past).

 

For my uses, I doubt that I will even use the PBI or the Cartridge port aspects, and instead will normally be docked to a PC via the built-in SIO2PC-USB, thus having the PC serve as my hard drive and print server. But at least I am trying to build in the possibility to use these other devices, but it has been a challenge.

 

 

Grrrrr. Sorry - my tools and VBXE boards are 2 floors down in the basement and the family is all sleeping. I'll get the stuff in the morning and take measurements for you then. Work can wait :)

 

No problem, I've waited this long so another day or two really doesn't matter. I just appreciate you taking the time to do this in the first place :)

 

- Michael

Edited by mytekcontrols

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Thinking more about what Dropcheck mentioned, I moved some stuff around and now should have good rear panel access to PBI Slot 1...

 

qZWcHno.png

 

And here is an example of Mini-ITX Motherboard for comparison...

 

U4Oj6zE.jpg

 

PBI Slot 2 would primarily be recommended for a device that does not need outside access (i.e., internal hard drive).

 

When I get a chance to update the schematics, I'll post them (quite a few changes).

 

- Michael

Edited by mytekcontrols
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