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JamesD

internal 16 bit 32K upgrade

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I am trying to find a 16bit internal 32k that ACTUALLY works and, preferably using a PCB of some kind.

 

I don't mind a kit, infact, I'd prefer one. I am in London UK.

 

Stephen

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The only recent mod with an available board keeps everything 8-bit (see the Hardware Project of the Quarter thread). Here's a link to a 16-bit mod--but it has no board. It is just a lot of wiring and chips. . .

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Has there been any prograss with this?

 

I have a few Ti-99/4a's that would benefit, especially as they'll be no more NanoPebs.

 

regards

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The board linked to from post 27 works fine, and has the same performance as the NanoPeb. :)

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I can add that I have thought of, but never implemented, a further feature of my memory expansion. Since I already have the logic to enable and disable parts of the memory expansion by setting individual CRU bits, now decoded with base address 400H, I could add a secondary decoding scheme. If I included a four bit DIP switch, to select a number between zero and fifteen, I could make the 4000H-5FFFH RAM segment also answer when a CRU bit at 1X00H is set. Thus the memory in my expansion could work as a DSR in RAM too. That would make it easier to implement virtual cards in the machine, like a RAM disk or whatever.

As it is now, the RAM disk I have implemented, relies on having the DSR software on one of my other expansion cards in the box. That's a card I've built myself, which has RAM in the DSR space, to allow for all sorts of modifications at run time. But the internal expansion would of course be more convenient if that wasn't needed to implement a RAM disk or whatever. You could perhaps implement a printout spooler or something like that.

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Here's a old 16/32K 16-bit daughter board sold back in 1985 by Radio Supply. I'm posting the pic for those who may be interested in the history. It had a 16k/32k switch attached to the wires you see that I removed and soldered it to 32k (the switch became flaky).

 

It did require you to unsolder the TMS9900 and remount it on the daughterboard. A chore not for the faint hearted. It doesn't appear that the motherboard has been modified by cutting traces; I see that the crystal is now mounted on the bottom of the motherboard and it has two wires on the top of the motherboard. But, they do not connect to the daughterboard.

 

Thanks to everyone for posting other mods. I've been interested in them so this is educational for me.

 

I used this console back in the 80's because it would assemble quite a bit faster than a normal console. It cut my development time down which was helpful. I never used it to play games so I wouldn't know how it reacted. Today, you can just use the PC for development; didn't have that back then (too bad!).

 

post-63752-0-13024900-1550688449_thumb.jpg

Edited by FALCOR4
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Ok, I realized that I was speeding a little bit when I said, ",,,it would assemble quite a bit faster than a normal console." I added the WDS100 HD at about the same time so, between the 16-bit memory AND the HD things went quite a bit faster. Opps :-)

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That's a bit of hardware I've never seen before--so documenting it is a good thing! Many thanks for identifying yet another item to add to my "hunt this down" list! :) :) :)

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Top Radio Supply

17885 Mt. Elliott

Detroit, Michigan 48212

 

My console is a beige non-v2.2 sent in as defective that, evidently, they repaired? Or, they bought repaired? It came with just the lower motherboard shield soldered to the board (top shield omitted) and a large resistor in-line with the power input (inside the console) to the newer switching P/S which may have been standard on those units by that time. There was a heat sink added to the 9918 and the 9904 does not have a heat sink. Looks like their board is a hand layout and not a computer layout. Something in-the-day you might etch in a pan or your sink (not saying i ever did that!!!!).

 

Those are some details that come to mind. It was a gift from Craig to me and my favorite console....

 

Doug

 

post-63752-0-59617300-1550800320_thumb.jpg

Edited by FALCOR4
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Ah, an HP 16C to brighten things up too! My copy of that calculator says Hello!

 

Swiss Micros? I have their HP41CX reproduction.

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Sorry, by "copy" I rather meant "instance". MIne is a genuine Hewlett Packard, acquired in 1983. It's now on its second set of batteries.

But my HP 15C is a modern re-run, which I bought a few years ago.

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We have the same desk!

In my closet is my console with the Top Radio Supply of Chicago mod - w00t daughter board technology.

Also, on my desk is my trusty HP 16C. I like it much better than TI's LCD Programmer, which always had double bounce key problems.

Thanks for the photo.

d.

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