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SDD 99


ralphb

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28 minutes ago, ralphb said:

Yes, sure, there is 32K, SAMS with 32 MB, serial port, parallel port, general I/O, CD sound, USB mouse ... and P-Code. ?  The GIO has two special pins which I'll demo in the next video.

Oh wow... P-code functionality! To me that by itself is worth the whole project :)

Well done!

By the way, you don't need a space between WRITELN and the parenthesis in P-code. Not sure why you've had that issue.

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9 minutes ago, Vorticon said:

Oh wow... P-code functionality! To me that by itself is worth the whole project :)

If you open a P-Code card you see that it consists (almost) entirely of ROM and GROM chips.  In other words, it is mostly software, but it needs a special environment to run, which I provide with the SDD.  The ROM and GROM files reside on the disk, which makes it easy to hack the P-system.  In fact, I eventually plan to speed up the disk access further by bypassing the slow VDP RAM -- it remains to be seen how feasible that idea is.

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1 minute ago, ralphb said:

If you open a P-Code card you see that it consists (almost) entirely of ROM and GROM chips.  In other words, it is mostly software, but it needs a special environment to run, which I provide with the SDD.  The ROM and GROM files reside on the disk, which makes it easy to hack the P-system.  In fact, I eventually plan to speed up the disk access further by bypassing the slow VDP RAM -- it remains to be seen how feasible that idea is.

Yes that opens up a lot of possibilities indeed. Is the current disk access speed similar to the original hardware or faster?

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7 minutes ago, Vorticon said:

Yes that opens up a lot of possibilities indeed. Is the current disk access speed similar to the original hardware or faster?

It's faster, but by how much I haven't measured.  Since normally, all the main programs (Main, Filer, Editor, etc.) are loaded sector-wise from floppy disk, having RAM disk-like access should speed this up quite nicely.  Also, you don't need to disk jockey with floppies, which is another benefit.

 

I'll do a side by side if I got time to prepare the disks and set up two systems.

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1 minute ago, ralphb said:

It's faster, but by how much I haven't measured.  Since normally, all the main programs (Main, Filer, Editor, etc.) are loaded sector-wise from floppy disk, having RAM disk-like access should speed this up quite nicely.  Also, you don't need to disk jockey with floppies, which is another benefit.

 

I'll do a side by side if I got time to prepare the disks and set up two systems.

I'll try to do the comparison this evening using your video demonstration as a benchmark. 

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6 hours ago, ralphb said:

Yes, sure, there is 32K, SAMS with 32 MB, serial port, parallel port, general I/O, Wifi, CD sound, USB mouse ... and P-Code. ?  The GIO has two special pins which I'll demo in the next video.

 

EDIT: Forgot wifi ...

Whoa. What is CD sound?

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16 hours ago, Asmusr said:

Whoa. What is CD sound?

Strictly speaking, it's Half-CD sound, i.e., 44.1 kHz audio with 8 bit resolution.  I could bump this up to 12 bits resolution, but I cannot hear a big difference.  The audio is piped into the TMS 9919 so that it's merged by the beeps from the TI and you hear it from your TV/monitor.  I think I presented the feature in my previous video.

 

You need to convert a WAV or MP3 file to plain PCM format, but then can play back the PCM file by CALL PLAY(<file>).  It's non-blocking, so you can use it in games, or simply as background music while typing in a BASIC program. ?

 

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  • 1 month later...
  • 1 month later...

Today I received my final boards, where final means that I won't change them again, unless there are any errors.  The layout is two centimeters narrower, but I cannot shrink it further, or the connectors won't fit anymore.

 

final-layout.thumb.jpg.d37b2911337a979e8b75e196f88b8f99.jpg

 

Over the next days I should receive some more parts I'll need, and then I can build a sidecart.  With that, I'll be able to test the self-update I implemented over the last weeks, and the parallel port and general I/O also need some work.

 

Keep your fingers crossed that this one works! ?

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1 hour ago, GDMike said:

Is that really it? Is that going to give us some great sounds? Really? It's here..or just about. I'm stoked

Any PEB version on the horizon?

No, it still takes some time.  Next week I will build the sidecar, then test it, and work on the firmware a little.  Then I can send out a few boards for beta testing.  If everything is OK, I can order some assembled boards, which are then for you.

 

If the built sidecar works, I can also start designing the PEB board, which keeps the main logic intact, but needs a new power supply and a reordering of connectors.  Maybe some connectors have to be removed.  Once the design is ready, the process will repeat.

 

Thus, the sidecar will be ready before the PEB card.

Edited by ralphb
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Ralph,

 

Glad to see things looking they are coming to near production time.  A couple of things I would suggest if you have not already thought about it.  Get a unit into someone's hands that can design a box for it to protect it.  Me personally, I do not like exposed circuit boards off the side of my TI's.  Between cats, dust, static, drinks, etc., too great of an opportunity to mess up the board.

 

Second, if and when you get the time if you have not already started the process, if you can get some kind of "beta" manual out there so we can start to read and understand the features that will get a lot of people excited.  I thought I read a post about it having WiFi capability as well, or maybe you were thinking of adding it.  Assuming WiFi capability is present, programming examples in both basic and assembly language on the interface for communications would be very nice.  Something similar to what Matt did for the TIPI.

 

If it does have WiFi capability so you can get to a TCP interface, then I will modify some code to create a terminal emulator interface for it for whenever you open up sales to everyone.

 

Beery

 

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12 minutes ago, BeeryMiller said:

Ralph,

 

Glad to see things looking they are coming to near production time.  A couple of things I would suggest if you have not already thought about it.  Get a unit into someone's hands that can design a box for it to protect it.  Me personally, I do not like exposed circuit boards off the side of my TI's.  Between cats, dust, static, drinks, etc., too great of an opportunity to mess up the board.

 

Second, if and when you get the time if you have not already started the process, if you can get some kind of "beta" manual out there so we can start to read and understand the features that will get a lot of people excited.  I thought I read a post about it having WiFi capability as well, or maybe you were thinking of adding it.  Assuming WiFi capability is present, programming examples in both basic and assembly language on the interface for communications would be very nice.  Something similar to what Matt did for the TIPI.

 

If it does have WiFi capability so you can get to a TCP interface, then I will modify some code to create a terminal emulator interface for it for whenever you open up sales to everyone.

 

Beery

 

And...if a peb version of the card is made, can't someone come up with a case for those too? Doesn't have to be metal

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48 minutes ago, GDMike said:

And...if a peb version of the card is made, can't someone come up with a case for those too? Doesn't have to be metal

 

Just my 2 cents...…...

 

For a 3D printer, something like that would have some significant cost due to printing time and needed plastic.  The way Ksarul has been designing his cards, I have not seen a need for a case.

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22 hours ago, BeeryMiller said:

Get a unit into someone's hands that can design a box for it to protect it.  Me personally, I do not like exposed circuit boards off the side of my TI's.  Between cats, dust, static, drinks, etc., too great of an opportunity to mess up the board.

 

Second, if and when you get the time if you have not already started the process, if you can get some kind of "beta" manual out there so we can start to read and understand the features that will get a lot of people excited.

Beery, I agree on both counts.  Early on, someone contacted me about 3d-printed cases (he also did cases for the FinalGROM).  You could also buy a right-sized plastic box as case, but you have to be careful to not put too much stress on the edge connector -- the PCB has to be at exactly the right height.  This is probably easier with a printed case.

 

I also will start on documentation soon.  The SDD is quite complex, and I think it would be nice if the beta testers will have some reference material as well.  I plan to do online but also a PDF version.

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22 hours ago, GDMike said:

And...if a peb version of the card is made, can't someone come up with a case for those too? Doesn't have to be metal

Yeah, I don't think that will be necessary ...  There are plenty of "official" cards that don't have a case!

 

Besides, ordering a PCB that fits the PEB box will be more expensive than a sidecar, since you have the bus connector at the bottom and the peripheral connectors at the top.  My go-to producer even has a 10x10 cm2 limit that probably wouldn't work for the PEB, so some creative solution is needed.

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  • 2 weeks later...

I just had a go at the new boards.  Suffice to say that my first board is junk, because of one new IC.

 

On my previous boards, I used a linear power regulator, because they're pretty simple to use.  But with upto 1.2 A (after recalculating the power usage) and 1.7 V voltage difference, that's more than 2 W and a lot of waste heat.  (It'd be even worse for the PEB card, since we have 8 V to regulate down to 3.3 V.)

 

So I decided to switch to a so-called step-down regulator, which does not produce that much heat.  You'll see the problem once you see the IC:

 

tps.jpg.9ed22bbc83809f4cddfe629b53b4ab32.jpg

 

The large pad on the bottom has no side connectors, thus cannot be soldered conventionally.  Either you put large vias below the pad that you can solder it "from below", or you use a heat blower and solder paste to solder this IC.  Either way is not made easier by the actual size of the part:

 

stepdown.thumb.jpg.f142c1a6cf8c3d0d17dd2f662d98c66f.jpg

 

Anyway, in my first attempt I used way too much solder paste, which did solder the IC, but also produced a viable short -- any pin is connected to all other pins. ?

 

I have 4 or 5 more of these ICs, let's hope I'm more successful with the next board! ?

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2 minutes ago, GDMike said:

Could you possibly just wire it from the pads to a bigger board?

That wouldn't do, since it's the IC that is so small (and not available any bigger).  Also note the (covered) copper areas around the IC; their size and geometry is set in the datasheet.  Any other layout, and the power supply might not work.

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