1088XLD - Custom A8 Computer in 1050 Drive Case

[+DrVenkman]

 

So what you want is to go back to the 400/800 ?

 

Nah...daughterboards are clumsy, introduce possible contact problems and make things much more expensive (connectors, extra PCBs to be manufactured etc.) Besides.....what can there that needs repair ? It's still all Atari chips in there

 

Um, no. If it ends up as an essentially-reconfigured 1088XEL, there will be PIC microcontroller chips for the keyboard, mouse and VGATE functions, there will be an FTDI serial-to-USB interface board, an Ultimate 1MB board and likely some variant of the logic setup for an XEL-CF PBI hard disk interface.

 

Plus the possibility of assembly errors, the risk of a bad solder joint or - yes - a bad Atari chip. They *do* fail occasionally, believe it or not.

[BillC]

@Michael:

 

If you are running into issues with what can fit in the drive bay opening you could use a custom faceplate similar to the one in the post below for the MEGA Speedy, which would allow use of the entire front edge of the main PCB. The upper port area could be enlarged as well if desired.

 

http://atariage.com/forums/topic/231176-mega-speedy-the-ultimate-1050-upgrade-intrest-assesment/page-15?do=findComment&comment=3822378

[Level42]

@Michael:

 

If you are running into issues with what can fit in the drive bay opening you could use a custom faceplate similar to the one in the post below for the MEGA Speedy, which would allow use of the entire front edge of the main PCB. The upper port area could be enlarged as well if desired.

 

http://atariage.com/forums/topic/231176-mega-speedy-the-ultimate-1050-upgrade-intrest-assesment/page-15?do=findComment&comment=3822378

 

God I need to finish that one....the issue is....the basis of that design is not 100% correct. the lower angle is wrong. I got it to fit on my 1050 but it required manual modding...

 

I lack the skills to do a real CAD drawing sadly.

[Level42]

 

Um, no. If it ends up as an essentially-reconfigured 1088XEL, there will be PIC microcontroller chips for the keyboard, mouse and VGATE functions, there will be an FTDI serial-to-USB interface board, an Ultimate 1MB board and likely some variant of the logic setup for an XEL-CF PBI hard disk interface.

 

Plus the possibility of assembly errors, the risk of a bad solder joint or - yes - a bad Atari chip. They *do* fail occasionally, believe it or not.

 

 

Yeah I realize what it will be, it will already have a number of "daughter cards".

 

I don't see how a module set-up makes it easier to replace a bad chip ? It's quite the opposite.... O well...the discussion is mute anyway...We will have to go whatever Michael comes up with....and I have little reason to doubt that what it will be will be great

[+mytek]

 

...there will be PIC microcontroller chips for the keyboard, mouse and VGATE functions, there will be an FTDI serial-to-USB interface board, an Ultimate 1MB board and likely some variant of the logic setup for an XEL-CF PBI hard disk interface.

 

Yep all except the built-in FTDI SIO2PC-USB on this one. Since there are two standard SIO ports, one of those can be used with a conventional external SIO2PC like the one Lotharek makes.

 

 

 

@Michael:

 

If you are running into issues with what can fit in the drive bay opening you could use a custom faceplate similar to the one in the post below for the MEGA Speedy, which would allow use of the entire front edge of the main PCB. The upper port area could be enlarged as well if desired.

 

http://atariage.com/forums/topic/231176-mega-speedy-the-ultimate-1050-upgrade-intrest-assesment/page-15?do=findComment&comment=3822378

 

I'm good, now that I figured it all out (or at least I think I am ).

 

 

Yeah I realize what it will be, it will already have a number of "daughter cards".

I don't see how a module set-up makes it easier to replace a bad chip ? It's quite the opposite.... O well...the discussion is mute anyway...We will have to go whatever Michael comes up with....and I have little reason to doubt that what it will be will be great

 

Of course it will be great ... just kidding . On another note: Today I have arrived at full connectivity between the schematic and the PCB layout. What this means is that I have a complete schematic with all parts assigned an ID, and a layout that has all the components placed to match. So other than a bit of minor tweaking here and there, I am nearly ready to route traces .

[+mytek]

PCB Update

 

I now have a schematic: 1088XLD_schema_preview.pdf

 

And here's the PCB layout in what might be a final form...

 

 

Looks to be ready for trace routing. But I'm tired, and don't want to jump into it until I've had plenty of time scrutinizing everything. But it's certainly beginning to take shape, and shows the potential .

 

Also you can now see all of the special headers for the upgrades (Sophia or VBXE, Rapidus, P-COVOX, and internal SIO devices), providing all the extra signals required that don't get picked up when piggybacking. Sophia RGB should work out of the box with the right cable specified. Sophia DVI can be made to work as well, but might require leaving one of the SIO connectors off to route the connector to the outside world. The XE version of the VBXE should drop right in, as well as the XE version of Rapidus. And of course we have the new P-COVOX board covered as well. Everything looks to be very accessible.

 

Besides the 12V going to the SIO (same as original 400/800), it is also present on the MPBI+ and on a separate power connector (along with 5V).

 

Edit: BTW, LED D11 is a placeholder until I find a right angle 3 lead bi-color LED that'll suit the physical and electrical requirements.

 

Edit2: Via the 2-4 Decoder (CD4555B), the 2nd 2-bit PS/2 port of the TK-II chip was sacrificed so that they now become addressable outputs for mouse selection/indication as well as provide a brief pulse to set the Disk Swap Latch circuit. These actions will be carried out via unused ALT+key combinations on the keyboard. The state of the mouse port select (i.e., which joystick port serves as the mouse) will be stored in non-volatile memory and restored upon power-up. Of course this will require a customized XLD version of TK-II firmware to repurpose the 2nd PS/2 port bits.

 

Edit3: The P-COVOX header also provides left and right audio inputs that'll get mixed in with the stereo Pokey outputs, thereby allowing all audio aspects to share a common output either through the DIN-13 jack or the 3.5 mm headphone jack on the interface daughter board. Could also be used by ivop's SIO Midi board.

[rockdoc2010]

I hope I didnt offend anyone. After i reread my post my lack of commas can be annoying. In college I got nailed for too many and then for not enough.

I think its awesome!!

Which system did you use as far as motherboard design? 800xl?

[rockdoc2010]

A must have. Digikey pn ED2108-ND

CONN IC DIP SOCKET 40POS GOLD

 

low profile and comes with a decoupling cap

 

8.10$ a piece

 

Other sizes as well

All my sockets on my 1200xl ran me about 80$

[Level42]

Uhhhh....that is very very expensive for a good socket and the built in capacitor is notmrequired as that filter cap is already in the schematics of the A8 and I bet Michael kept those in.

 

I get sockets from AliExpress which are fine and wayyyyy cheaper but if you want brand ones, even those should be around 1,50/2 bucks a piece.

Edited August 6, 2018 by Level42

[+mytek]

Which system did you use as far as motherboard design? 800xl?

 

I'll assume you are referring to the electronic design and not the PCB layout which is nothing like any standard A8 system. It's a mash-up of different A8 system glue logic as well as a lot of my own.

 

 

A must have. Digikey pn ED2108-ND

CONN IC DIP SOCKET 40POS GOLD

 

low profile and comes with a decoupling cap

 

8.10$ a piece

 

Other sizes as well

All my sockets on my 1200xl ran me about 80$

 

I hate to burst your bubble, but to reiterate what Level42 said, you pay a lot to get that decoupling cap built-in, and there is absolutely no reason to do that since those already exist on the mother board. To give you an idea of the difference in price, I use these from Phoenix Enterprises...

 

HWS2632 LINK

 

Edit: Also it's not likely that the cap will be connected to the correct pins anyway, surprised that didn't cause problems for you.

[seastalker]

Whoa Mytek, you released the plans on the 1088XLD that fits the 1050 drive? HUGE HUGE thanks!

[+mytek]

Whoa Mytek, you released the plans on the 1088XLD that fits the 1050 drive? HUGE HUGE thanks!

Just the schematics, and not everything has yet been verified. Hence the reason it says 'PREVIEW'.

 

And yes the 1088XLD is destined for using the 1050 case, and is a drop in alternative for the original 1050 PCB. I say alternative, since it is a computer, and no longer a floppy drive controller as the original board was intended to be.

[Level42]

....and suddenly it crossed my mind
...why not let the 1050 be a computer AND 4 Floppy disk drives in one ??

Sdrive Max fits PERFECTLY...

There's only one slight issue...the SD card slot is rather unreachable this way....

...oh....and the software would need a re-write to run in horizontal mode.....

Edited August 8, 2018 by Level42

[guus.assmann]

Hello,

 

Looks ok, there's room for 2.

 

If you go to Ebay and seach for SD extention, you will find a connector, cable and a micro-SD slot.

That way, you can place the card anywhere. (Cable is quite long)

 

BR/

Guus

[Level42]

Ah ! GREAT TIP....already was thinking about making something myself but this would be a lot easier !

something like this would be fine I guess:

https://nl.aliexpress.com/item/TF-to-micro-SD-card-Flex-Extension-cable-Extender-Adapter-reader-car-GPS-mobile-25CM-Memory/32731755112.html?spm=a2g0z.search0104.3.109.414c1abbjDQqE6&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10151_10065_10344_10068_10342_10343_10340_10341_10696_10084_10083_5011515_10618_5011615_10304_10307_10820_10301_10821_5723615_10843_10059_100031_10103_10624_10623_10622_10621_10620,searchweb201603_54,ppcSwitch_7&algo_expid=ca97b198-56b2-48c5-9f06-64fdd184ab0d-17&algo_pvid=ca97b198-56b2-48c5-9f06-64fdd184ab0d&priceBeautifyAB=0


Only issue is mounting the new slot in a neat place...I guess it can be glued at a nice "hidden" but still accessible spot....maybe the right side of the bezel....

 

So that leaves only the horizontal software issue

 

Yeah, I thought about two of them too, but wouldn't be all that useful ? Not sure if the software allows the drives to be used as D5:--D8:
Also, it would be a nice area to insert a dark piece of black plastic for stuff like LED's, ,maybe the SD slot, etc.

May need to make an extension cable from the USB port of the Arduino too....for flashing firmware....although ....you don't do this everyday. But it would still be better than having to open it up every time you need to flash it....

Edited August 8, 2018 by Level42

[Level42]

Michael, do you have the outer sizes of what the PCB will be ?

 

Never mind.....stupid question while I have the empty case here....

Edited August 8, 2018 by Level42

[+mytek]

....and suddenly it crossed my mind

...why not let the 1050 be a computer AND 4 Floppy disk drives in one ??

 

Sdrive Max fits PERFECTLY...

 

There's only one slight issue...the SD card slot is rather unreachable this way....

 

...oh....and the software would need a re-write to run in horizontal mode.....

 

Interesting idea on the Sdrive Max. However it isn't going to change my approach which will give me even more drive flexibility, and of course speed utilizing Jon's U1MB BIOS and a built-in CF drive.

 

Good luck with your project .

[Level42]

 

Interesting idea on the Sdrive Max. However it isn't going to change my approach which will give me even more drive flexibility, and of course speed utilizing Jon's U1MB BIOS and a built-in CF drive.

 

Good luck with your project .

 

Well one doesn't rule out the other, right ? My suggestions/ideas/brainfarts _never_ imply you should change your approach Michael....but it's never bad to share ideas IMHO...I think your past projects benefited from some external ideas too ? (Not sure on this actually....LOL)

 

The only issue there could be would be space, but since U1MB will be more towards the power switch and still sit quite low I'm confident there will be enough space.

 

Also: since I never worked with a 1088XEL I know little about Jon's CF-drive functions but I assume this is more like a harddisk than a floppy emulator? One of Sdrive-Max really nice features is being able to run ATX, not sure if that is possible with CF too ?

I never really had any Harddisk or emulation of one for my A8's....all I have are cartridge solutions (one with CF card, My-IDEII) and now the Sdrive-Max. (Oh and of course a MegaSpeedy 1050 and a happy 1050, but those are here just for fun).

(By the way, CompactFlash is rather outdated isn't it ? This already seems like a retro-format to me now....time marches on.......no SD card possibility ? )

Edited August 9, 2018 by Level42

[+mytek]

Well one doesn't rule out the other, right ?

 

You are correct, and I was probably mistaken to suggest in all ways that the CF drive was superior to the Sdrive Max. A better way to put it was for my project this would not be a way I will likely go. For one thing, if I factor in the front panel Cartridge access, the Interface Board connectors/status LEDs, and the CF drive slot(s), there would be no where left to put the device and still see the LCD screen unless one wished to butcher the 1050 case, which I am really trying very hard to avoid if at all possible. Besides not being able to load ATX files, which doesn't interest me in the least (hey that's the truth ), the CF drive offers much faster access, and via the U1MB Loader much easier navigation and search (plus it's way easier for these old eyes to read stuff on the main screen instead of a tiny LCD display).

 

Edit: Don't get me wrong, I think the Sdrive Max is a very cool and extremely useful device. And probably the best floppy emulator you're ever going to see connected to the SIO port.

 

 

 

....but it's never bad to share ideas IMHO...I think your past projects benefited from some external ideas too ?

 

Share a way, and yes the 1088XEL (as well as this project) did benefit from others ideas, as well as troubleshooting help when I ran into problems on the XEL. But ultimately this is my project, which as I've pointed out before, is not being built to please anyone except for myself. It's my plan, my journey, which I've decided to allow other people to follow along as I go. Unfortunately I've noticed all too often on AA that people think that they have a free pass on telling others how to do things when projects like this are shared. Granted they probably think they are doing someone a favor, and/or pointing out something that was forgotten, but that is not always the case. Some people just think their ideas are better, and/or want it to be their way. Referring to that last sentence... I will admit that I have no tolerance for that way of thinking.

 

So let me outline the 1088XLD game plan as I see it.

• It is for the most part being built from proven 1088XEL technology.
• It is simply a repackaging of such.
• It is not about advancing said technology.
• At this point in time, the design is frozen, except for any minor updates that may be required to correct any inaccuracies that might have crept in.
• This is being done for my pleasure. Think of this as the ultimate maze style adventure game.
• This may or not actually get completed, may or may not become a public release.
• I reserve the right to take whatever path I desire, and/or to disagree with other people's suggestions.

The XEL was designed with a public release in mind, so it only made sense to allow a lot of public influence to determine the development direction. The XLD for lack of better words, is presently following a closed development path. This doesn't mean all suggestions are ignored, but it does mean that I decide if I like the suggestion and/or incorporate it.

 

 

 

By the way, CompactFlash is rather outdated isn't it ? This already seems like a retro-format to me now....time marches on....I'd need to buy a reader for CF for my Mac to transfer files....no SD card possibility ?

 

Hmm... Atari's could be considered outdated as well, or at the very least retro . Speaking of which, the IDE/CF technology existed for the Atari 8-Bit back in the day, thanks to a large degree to Bob Woolley's articles. So yes it is retro, but it's from the same era as the A8, so it only seems appropriate to use it. Food for thought, a 1450XLD really could have been built in this way.

 

There are SD adapters that'll work, but I prefer the CF cards for this specific application (IDE interfaced system) because for one, they just work a bit better and without some of the quirks that the adapter introduces. And secondly, although this may sound foolish, CF cards remind me of the data wafers from Star Trek (yes I know... very retro indeed). And last, but not insignificant, most of the adapters are not very ergonomic, requiring removal each and every time you wish to change the SD card .

 

 

 

Also: since I never worked with a 1088XEL I know little about Jon's CF-drive functions but I assume this is more like a harddisk than a floppy emulator?

 

Yes definitely a hard drive approach, implemented in a transparent non-invasive way. Meaning it does not require removal, does not take up the cartridge slot, SIO port, or any other normally used connection. In every sense it is truly the way it should be done, and mirrors modern systems in this regard. Almost identical to how the Incognito CF card works (edit: as well as the original Bob Woolley and early MYIDE hardware designs).

 

So that's my story .

[+mytek]

Now that I have schematics and a PCB layout that matches the number of components and IDs, I will be taking a leave of absence from this project to pursue other things. It was important for me to get it to this state before setting it aside, so that I could purge my brain of all the details before moving on. I plan to resume work on this project towards the end of this year.

 

To be continued...

[+mytek]

Schematic Update: Video Section --- Primary Oscillator

 

 

Incorporates New Dual Selectable Oscillator Circuit

 

 

After looking at the pricing on the TTL Clock Oscillators, especially for PAL (5 USD), and the fact you would still need to swap these out when changing video standards, I decided to go back to crystals, but with a twist. Via a single jumper, PAL or NTSC will now be selectable (same jumper that formally selected only the V-Gate 'No-Color' chroma bias voltage). So this means the crystals can all be soldered in place.

 

I just completed testing on a protoboard and it works like a charm, but I'll also need to wire this up on a piece of vector board to be sure it'll work without the protoboard's extra capacitance.

 

Of course you'll still need to swap GTIA and Antic .

 

 

 

[Level42]

Or get an AntiX and be able to switch between the best of both worlds .....if you can live with a hybrid solution....

I always thought a PAL machine required two crystals to be operating, but this schematic only has one output, so I guess it outputs either NTSC -or- PAL frequency ?

Could you explain how the circuit works a bit ? Thanks !

Edited August 16, 2018 by Level42

[flashjazzcat]

There are three crytals in total. X3 provides the clock for the PAL colourburst circuit in the first schematic.

[+mytek]

Or get an AntiX and be able to switch between the best of both worlds .....if you can live with a hybrid solution....

 

I always thought a PAL machine required two crystals to be operating, but this schematic only has one output, so I guess it outputs either NTSC -or- PAL frequency ?

 

Could you explain how the circuit works a bit ? Thanks !

 

Yes AnticX is definitely going to be easier for a lot of situations. But for those without a Sophia or a PAL-M monitor, or programs that need things to be truly PAL, then there is still a need for crystal swapping.

 

As Jon pointed out, X3 is the 3rd crystal that produces the color burst clock for PAL. Basically the X3 circuit is being synced with the primary system clock, but puts out a different crystal locked frequency required by a PAL GTIA on pin 16 (a pin with no internal connection on an NTSC GTIA chip) to properly produce color.

 

Edit: Just to add to this... X1 or X2 (whichever is selected) will put out the proper 'System' clock for GTIA, which gets divided in half for the CPU. However due to the difference in how PAL works vs. NTSC, a different frequency then can be easily derived from the system clock is required to produce the color burst signal for PAL. Without this signal which is synced to in a PAL TV, you will only have a B&W picture. However the system will still work correctly in all other aspects.

[AtariGeezer]

Think I'll hold off on building my 2nd XEL in favor of this new cool project

 

I'll get New Eyes next month (cataract surgery) so I'll be able to see a whole lot better. It will allow me to stop using magnifying glasses to see. If it wasn't for my VA benefits, I'd be screwed...