Manic1975 Posted July 7, 2016 Share Posted July 7, 2016 YES!! A new 32k memory expansion for side port! If we add floppy controller (with HxC) to this memory expansion we have CF7+ solution! Quote Link to comment Share on other sites More sharing options...
+save2600 Posted July 7, 2016 Share Posted July 7, 2016 If this becomes reality, be nice if it had a case available. Far too many of these projects are allowed to lay neked among our legacy peripherals. Must be a new millennium thing. Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 7, 2016 Author Share Posted July 7, 2016 I've been thinking of building it to fit an off the shelf project box. But no promises at this stage. -M@ 4 Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted July 17, 2016 Share Posted July 17, 2016 Any updates on this cool little project? /putting the cart before the horse mode ON An off-the-shelf box would be nice, but with all these 3D printed object out there, I'd love to see a case eventually made for this with a little 'STYLE'. Maybe even an inset where a person could attach a piece of aluminum trim to match the TI's case? Who knows, once the dimensions are known, maybe even a competition to see who could design the coolest looking enclosure? Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 18, 2016 Author Share Posted July 18, 2016 The problem with these hobby projects getting 'style', is it is rare to find someone who's hobby has all of those ingredients. And then, my personal tastes will not be the same as others... I actually love the look of a circuit board... I probably have ever since the first time I took my TI apart, from curiosity. I'd love to take on 3-d printing, but then you'd have to wait about 5 years for me to finish this... I haven't been able to get the hang of any 3-d modelling software since "Imagine" for the Amiga. But If someone with style wants to hit this with a can of magic, then I would welcome that. Of course, the hardware needs to be working first. On the progress side, I haven't had success making the prototype work without the buffers. The behavior is very strange. I wish I understood oscilloscopes better. I sent two pcboard layouts to OSHPark yesterday. something like the pi-cobbler t-shaped ribbon cable to breadboard, to make working on the side port with a breadboard more tolerable. a layout for the circuit I did get to work, with the buffer chips and all that. It is something like 4.25"w x 3.25"h. If this board works, I'll open source it, but it won't be the final version that I intend to assemble. I still want to try a couple other layout patterns... Here is what I sent off to OSHPark: Now I need to remember who sells those 'give the foot the boot' ribbon cables for the side port, for my prototyping work. Oh, the pinouts on my protoboard side are reversed for the top of the sidecar. It was just easier that way. Oh, and here is the candidate box, I would like the 32k to fit in for my own personal taste: ( never mind the stuff inside, that's just some Amiga tom-foolery ) -M@ 3 Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted July 18, 2016 Share Posted July 18, 2016 Now I need to remember who sells those 'give the foot the boot' ribbon cables for the side port, for my prototyping work. You want to go << HERE >> as it's the cheapest option and it's from the same exact place as the more expensive website. It even has the same stock number. 1 Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted July 18, 2016 Share Posted July 18, 2016 Screenshot_071716_105302_PM.jpg ( never mind the stuff inside, that's just some Amiga tom-foolery ) -M@ I shall not ignore the Amiga stuff... I like the cut of your jib. 1 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted July 18, 2016 Share Posted July 18, 2016 1 Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 18, 2016 Author Share Posted July 18, 2016 You want to go > as it's the cheapest option and it's from the same exact place as the more expensive website. It even has the same stock number.THANKS! Thats perfect. -M@ Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 18, 2016 Author Share Posted July 18, 2016 I shall not ignore the Amiga stuff... I like the cut of your jib.I need to take a look and see if that PicoPSU had -5v, it might be applicable to the TI if it does. I got bored on my last business trip and ended up winning an ebay PAL Amiga 1200. So I adapted this ATX supply. I used the crimp on pin tips for male DB25 connectors instead of bothering with some ATX socket harness. BITD my A1000 had a power switch on the computer, my PC before that had a power switch on the computer, and my TI had a power switch on the computer. I was a little astonished that the A1200 did not. That reminds me, I need to add a switch to the final pcboard layout for this 32K expansion. If i figure the pass thru layout, i want to have the externally supplied +5V feed the +5V pin on the outgoing connector, instead of what the TI supplies, as the TI output is limited to what the speech board needs. -M@ Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted July 18, 2016 Share Posted July 18, 2016 I was going to use a PicoPSU in the TI, I just never got a round tuit. As I recall, to be ATX-compliant is has to provide -5VDC. Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 18, 2016 Author Share Posted July 18, 2016 I was going to use a PicoPSU in the TI, I just never got a round tuit. As I recall, to be ATX-compliant is has to provide -5VDC. The AT 20 pin spec requires -5VDC, but the ATX 24 pin spec denotes -5VDC as optional, which means ATX motherboards probably don't use it. But the ATX PicoPSU I have had a 20 pin connector... which gives me hope that it might supply the -5VDC... easy enough to test... I just need a moment without laziness... -M@ Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted July 19, 2016 Share Posted July 19, 2016 I just went hunting through the manuals on the Mini-Box site--none of the PicoPSU variants I looked at had the -5V. I looked at the 120 (with 20-pin connector) and the 150 and 160 (with 24). I also looked at the Yoosoo equivalents, they don't have the -5V rail either. Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 19, 2016 Author Share Posted July 19, 2016 I guess that is why we have this thread over here: http://atariage.com/forums/topic/252838-ti-replacement-power-supply/#entry3514542 I'll continue to be lazy then. I like lazy. -M@ Quote Link to comment Share on other sites More sharing options...
Stuart Posted July 27, 2016 Share Posted July 27, 2016 jedimatt42, on 07 Jul 2016 - 07:06 AM, said: I gave it a shot today without the buffers, but it behaved very badly... manually, not connected to the TI, I can walk through the range of values A0-A2 with memen grounded, and get the CS output I want.. But connected to the 4a, it just seems to respond to all address ranges. Anyway, I'll have to strip it down, and try again. I may try just buffering A0-A2 two see if that fixes the selection. I'm interested in being able to run with 3 less chips.. not so much because of the buffer chips cost, but because the pcboard can get to be significantly cheaper the smaller it is. Edit: ( I found the TI-99/4a Console Technical Data pdf on mainbyte... A Big thanks to the owner of that site! ) -M@ Matt, have you had a chance to progress this? I've knocked up the circuit on a breadboard with no buffers and it works OK**. Just the LS138, LS21 and the 62256 RAM. LS21 pin 6 is connected to the RAM /OE and /CS. The LS21 should be able to directly drive a small LED (with current limiting resistor) as well. (** Frustrating to start with. My console has 32K 16-bit internal RAM running with no wait states, and a switch to disable. But the switch disabled the RAM but didn't disable the 0 wait states when accessing the 32K RAM area. So with the breadboard RAM circuit attached, it was somehow reading the address back as data. For example, stepping through the bytes from address >A000 using EasyBug would give the data >A0, >01, >A0, >03, >A0, >05 and so on. Very confusing. Had to rewire the switch so it gave the normal wait states as well when internal RAM disabled.) Stuart. 1 Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 28, 2016 Author Share Posted July 28, 2016 Stuart, I'm not surprised that you got it to work... for so many reasons, but also cause you were right, the stuff is already buffered on the side-port. Question: did you externally power things, or take the power off of the console? Tomorrow I'll share the schematic I was trying without the buffers. In the meantime I had a couple boards printed to test, and those just arrived today. Mem boards that are wired for the buffers, although in theory I could jumper them instead of installing the chips to test skipping the buffers.. And something to help keep my sanity on the bread-board. I have the labelling wrong, as I didn't consider the pre-fab extension cable.. I also have the pin spacing on the edge card wrong, but am able to 'compress' the pins on the connectors I have and make it work. I'll use a sticker to fix my labelling And then update (correct both problems) and share the bread-board bit on osh-park. -M@ 2 Quote Link to comment Share on other sites More sharing options...
Stuart Posted July 28, 2016 Share Posted July 28, 2016 Question: did you externally power things, or take the power off of the console? Powered directly off the side port. Draws around 8mA when running a simple XB program - that will vary a bit depending on how bright your LED is (mine is fairly dim). Well within the 50mA max guideline in the console spec. Nice looking PCBs! Quote Link to comment Share on other sites More sharing options...
cbmeeks Posted July 29, 2016 Share Posted July 29, 2016 What's the latest on this? Me wanty. Me wanty very much. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted July 29, 2016 Share Posted July 29, 2016 Stuart, I'm not surprised that you got it to work... for so many reasons, but also cause you were right, the stuff is already buffered on the side-port. Question: did you externally power things, or take the power off of the console? Tomorrow I'll share the schematic I was trying without the buffers. In the meantime I had a couple boards printed to test, and those just arrived today. Mem boards that are wired for the buffers, although in theory I could jumper them instead of installing the chips to test skipping the buffers.. And something to help keep my sanity on the bread-board. IMG_20160727_182653.jpg IMG_20160727_194418.jpg IMG_20160727_194442.jpg I have the labelling wrong, as I didn't consider the pre-fab extension cable.. I also have the pin spacing on the edge card wrong, but am able to 'compress' the pins on the connectors I have and make it work. I'll use a sticker to fix my labelling And then update (correct both problems) and share the bread-board bit on osh-park. -M@ Are these available yet on OshPark, I can't seem to find them? Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 29, 2016 Author Share Posted July 29, 2016 They are not, i need to test them first. And i already know i need to revise both. -M@ Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted July 30, 2016 Author Share Posted July 30, 2016 What's the latest on this? Me wanty. Me wanty very much. It is still in development. And to be open, I've got too much travel this month. Hopefully I can prepare some options while away to test once the travel subsides. -M@ 1 Quote Link to comment Share on other sites More sharing options...
mindlord Posted August 3, 2016 Share Posted August 3, 2016 This project fills an void in the TI universe. I applaud your efforts, and I extremely interested at least two of these. Quote Link to comment Share on other sites More sharing options...
warpman Posted August 3, 2016 Share Posted August 3, 2016 Most excellent work. I would be interested in two of these as well. Quote Link to comment Share on other sites More sharing options...
Hablemän Posted August 8, 2016 Share Posted August 8, 2016 Hi, please sign me in as well for one piece and give me a short confirmation, please. THANKS! Stefan Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted August 9, 2016 Author Share Posted August 9, 2016 I appreciate the enthusiasm, but the product doesn't exist yet. So I am not taking names or making any lists. The first breadboard prototype worked. Once i get back to the USA and recover, I hope to have time to build the proof of concept pcboard that is waiting on my desk. But as i have discussed in this thread there is another prototype breadboard design i want to get working or understand why it won't work before i do another proof of concept pcboard. Then if that works out, I'll price and buy a reasonable quantity of parts. And start building them for sale. If i am lucky, i have an ah-ha moment, before my next trip, and can get some steps in motion. But I would guess that we are looking at October. That is just a guess. -M@ 2 Quote Link to comment Share on other sites More sharing options...
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