Kchula-Rrit Posted November 25, 2023 Share Posted November 25, 2023 My main interest for my TI is to use the Editor/Assembler cartridge to write programs. Then I decided it would be nice to have some RAM and ROM in it, so I could keep some library routines at hand. Since the E/A cartridge has no provision for a RAM chip and I did not wish to piggy-back on onto the cartridge, my next thought was to make an adapter to use a breadboard to emulate what I wanted. That PDF of Bunyard was my inspiration for this whole thing. I ordered some 36-pin edge connectors and made an adapter to plug into a breadboard. Then I found that the fingers on the edge connector are too short to make good contact with the console's connector. Realizing that my Linux distribution has KiCAD in it, I drew up a board, taking the measurement for the fingers from an unused ROM cartridge I bought a long time ago. Here's a picture of the top side: Now I just have to find someone to make it. I was thinking of PCBWay, but they are in China, which probably means at least a month-long wait and import duties and such. Are there any in the US who still do small runs that are relatively inexpensive? K-R. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted November 25, 2023 Share Posted November 25, 2023 17 minutes ago, Kchula-Rrit said: My main interest for my TI is to use the Editor/Assembler cartridge to write programs. Then I decided it would be nice to have some RAM and ROM in it, so I could keep some library routines at hand. Since the E/A cartridge has no provision for a RAM chip and I did not wish to piggy-back on onto the cartridge, my next thought was to make an adapter to use a breadboard to emulate what I wanted. That PDF of Bunyard was my inspiration for this whole thing. I ordered some 36-pin edge connectors and made an adapter to plug into a breadboard. Then I found that the fingers on the edge connector are too short to make good contact with the console's connector. Realizing that my Linux distribution has KiCAD in it, I drew up a board, taking the measurement for the fingers from an unused ROM cartridge I bought a long time ago. Here's a picture of the top side: Now I just have to find someone to make it. I was thinking of PCBWay, but they are in China, which probably means at least a month-long wait and import duties and such. Are there any in the US who still do small runs that are relatively inexpensive? K-R. PCBWAY does a good job, and then prices are good. They send back via DHL, which means not a month wait but about 2 weeks. Quote Link to comment Share on other sites More sharing options...
Tornadoboy Posted November 26, 2023 Share Posted November 26, 2023 (edited) PCBWAY is Chinese and the OP mentioned wanting a US company. I use them myself but feel like I need to take a bath afterwards given they're under CCP rule. OSHpark is an American PCB manufacturer that'll do small orders though they're not nearly as cheap. Edited November 26, 2023 by Tornadoboy Quote Link to comment Share on other sites More sharing options...
+Torrax Posted November 26, 2023 Share Posted November 26, 2023 You can also make a 8K SuperCart with the following project. Had one made in the early 1990's using an old PARSEC cartridge board (game ROM went bad). http://www.mainbyte.com/ti99/supercart/supercart.html 2 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 26, 2023 Author Share Posted November 26, 2023 Thanks for the ideas! I will look into them soon. K-R. 1 Quote Link to comment Share on other sites More sharing options...
+FarmerPotato Posted November 26, 2023 Share Posted November 26, 2023 I'm using Aisler, which make them in Europe. More competitive than OSH Park; price/inch goes down the bigger the board. From three orders, delivery to US was in 10 days, 8 days, 14 days. What was annoying was the last one, which sat in Frankfurt for 5 days after shipping. 3 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 26, 2023 Author Share Posted November 26, 2023 Bad news! I tried the PCBWay quote site, which initially said $5 for five boards. When I added an edge connector the price shot up to $279! I did not think edge connectors were that much harder to make. OSHpark reported $5 per square inch. Aisler gave a price for my size board of about 17 for three boards, which I assume is in the neighborhood of $20. These two made no mention of edge connectors. I was really hoping to avoid making a "Frankencart," but I may have to do so, or take the riser from my dead console and swap-out the edge connector for an IDC one. I have a ROM cartridge that I bought some time ago (do not remember when) for a 64KByte ROM. Since TIs do not boot from ROM-only cartridges I figure I can sacrifice it. Looks like it has all the traces I need. Just had a thought. Since I am pretty much using only the Ed/Assem cartridge (no ROM) maybe I could put the 8K RAM on the 16-bit bus. Have to think about it. Still kind of "gun-shy" about killing a console with a botched RAM expansion thirty years ago. K-R. Quote Link to comment Share on other sites More sharing options...
Tornadoboy Posted November 26, 2023 Share Posted November 26, 2023 That's weird, I've had PCBWAY make JAMMA adapters which have 56 pin edge connectors for $5 per set of 5, all I can think is you must have selected a wrong option somewhere. @FarmerPotato, I'll have to check them out, I'd much rather buy from Europe than China and OSHpark is a little on the pricey side. That's not a knock on the Chinese people, it's the CCP I have a problem with. 1 Quote Link to comment Share on other sites More sharing options...
+FarmerPotato Posted November 26, 2023 Share Posted November 26, 2023 @Kchula-Rrit like @Tornadoboy said, you must have selected a wrong option. I got 11 cartridge boards from dirtypcbs.com for $20. They have to fit within 10x10 cm , which is adequate for a standard cartridge. Took 4 weeks because, hey, they promise dirt cheap. Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 27, 2023 Author Share Posted November 27, 2023 I tried the Web-sites and here are my experiences: PCBWay: I selected these options, and left all others at defaults: Board Type = Single Pieces Size = 99.1 x 94.0 Layers = 2 Edge Connector = Yes (Bevelling it did not seem to change the price, but I figured it would make for easier insertion, so I picked it.) The default for Edge Connector was "Hard Gold," which gave the $277 prince. Changing it to "Immersion Silver" lowered the price to $64. NOTE: PCBWay did not ask for info about the width of the edge connector, nor how long the fingers are. Aisler One nice thing about Aislers was that they would take KiCAD files directly. This sounds like a good thing, since I am not sure which files I would otherwise need to upload. When I told KiCAD to "export Gerber files," it made about 20 different files, I assume one for each aspect of the board's construction. I used their "upload board" function. It took the ".kicad_pcb" file from my project and pointed-out some some mistakes. My mounting holes were 0.125-inch radius, instead of my intended diameter. It also did not like the right-angles where the edge connector joined the rest of the PC board. I fixed both mistakes, correcting the mounting holes and giving the connector-to-board joint a 0.125-inch radius. The "insufficient outline clearance" error is one that I had no idea what the problem was or how to fix it. The "unfavorable copper distribution" means that there is no copper layer. This board has no copper plane(s), so this, at least, is not a problem. I did not get an estimate from them. OSHPark: Had the advantage that I could just upload the ".kicad_pcb" file. Their estimate was $73 for three boards. DirtyPCBs Their site seemed rather cryptic. It said "upload files," but did not say which of the 20 ".gbr" files KiCAD spat out. Given my attempt with Aisler, it might want the ".kicad_pcb" file. All of them: I got the impression that, to get a "better" quote, the sites wanted me to have an account or commit to an order. Not sure I want to do that, just to get an estimate. Mind you, I am totally new to this, so am not sure if this is the normal way to do these things. Last time I did anything like this was matching-up 4x4 foot board drawings with a schematic in 1984. The company had other people to deal with the fabrication part of it... K-R. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted November 27, 2023 Share Posted November 27, 2023 50 minutes ago, Kchula-Rrit said: I tried the Web-sites and here are my experiences: PCBWay: I selected these options, and left all others at defaults: Board Type = Single Pieces Size = 99.1 x 94.0 Layers = 2 Edge Connector = Yes (Bevelling it did not seem to change the price, but I figured it would make for easier insertion, so I picked it.) The default for Edge Connector was "Hard Gold," which gave the $277 prince. Changing it to "Immersion Silver" lowered the price to $64. NOTE: PCBWay did not ask for info about the width of the edge connector, nor how long the fingers are. Aisler One nice thing about Aislers was that they would take KiCAD files directly. This sounds like a good thing, since I am not sure which files I would otherwise need to upload. When I told KiCAD to "export Gerber files," it made about 20 different files, I assume one for each aspect of the board's construction. I used their "upload board" function. It took the ".kicad_pcb" file from my project and pointed-out some some mistakes. My mounting holes were 0.125-inch radius, instead of my intended diameter. It also did not like the right-angles where the edge connector joined the rest of the PC board. I fixed both mistakes, correcting the mounting holes and giving the connector-to-board joint a 0.125-inch radius. The "insufficient outline clearance" error is one that I had no idea what the problem was or how to fix it. The "unfavorable copper distribution" means that there is no copper layer. This board has no copper plane(s), so this, at least, is not a problem. I did not get an estimate from them. OSHPark: Had the advantage that I could just upload the ".kicad_pcb" file. Their estimate was $73 for three boards. DirtyPCBs Their site seemed rather cryptic. It said "upload files," but did not say which of the 20 ".gbr" files KiCAD spat out. Given my attempt with Aisler, it might want the ".kicad_pcb" file. All of them: I got the impression that, to get a "better" quote, the sites wanted me to have an account or commit to an order. Not sure I want to do that, just to get an estimate. Mind you, I am totally new to this, so am not sure if this is the normal way to do these things. Last time I did anything like this was matching-up 4x4 foot board drawings with a schematic in 1984. The company had other people to deal with the fabrication part of it... K-R. My one experience with PCBWAY was good I ordered TN-VDP boards from the gerbers provided at the authors site, each board was in a gerber zip file containing all the gerbers for that board, and then I also added edge card to IDC adapters for floppies that they already had gerbers for. Costs me $5 dollars per 5 pieces of tang adapter and vdp adapter and 5 for 10 edge card adapter,s, no beveling. costs 15 + 20 dollars shipping for all. Came in about 2 weeks thru DHL. FYI Quote Link to comment Share on other sites More sharing options...
+FarmerPotato Posted November 27, 2023 Share Posted November 27, 2023 "insufficient outline clearance" Zoom in on your outline cut--how close is any feature? Do you have doubled up line segments? (tricky) What about double lines around the edge connector? In Kicad, take advantage of its error checks. Click the tool with the bug icon. To check the outline, use the 3D Board Viewer. It will detect errors in the outline cut. (polygon not closed, others) Each house may have their own rules--they will flag an edge cut if it they know it will jeopardize a feature too close to the edge. Aisler is picky about leaving room for solder mask between copper and board edge. I imagine a really thin sliver of solder mask coming off? "Unfavorable copper ratio". You want them to etch away 99% of the copper? For some reason they consider this risky. In Kicad, Add a plane fill over the outline cut. On the front, create a plane fill to +5, use GND on the bottom. This will keep most of the copper. For your use, it's not necessary to plate the edge fingers. They oughta come back tin plated. If you really want gold, it can be done at home too. 3 Quote Link to comment Share on other sites More sharing options...
Stuart Posted November 27, 2023 Share Posted November 27, 2023 Note about the Gerbers ... seems common to zip them all up together and use the zip file as 'the gerber file'. 2 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 27, 2023 Share Posted November 27, 2023 One note on supercart boards--I have a number of bare boards here, already made, that allow from 8 to 32K RAM (4 switch-selectable 8K banks) and battery backup. I sell them for $7 each, shipped to a US address. . .may be faster than the manufacturing route, although these don't have the extra 36-pin connector to plug another cartridge into the board. 2 Quote Link to comment Share on other sites More sharing options...
+FarmerPotato Posted November 28, 2023 Share Posted November 28, 2023 Another tip about PCB houses: they will have design rules -- for instance minimum distances between thru-hole and fill or mask. This is what the "Bug" tool checks. (DRC) The PCB house will run a DRC too, but after making sure that THEIR minimums are applied. If you didn't change any of the KiCad defaults and the PCB house didn't report any problems, you're probably ok. I got in trouble where I raised the minimum clearance between trace & thru-hole for GND net. What rendered on my screen was different from Aisler's board rendering--specifically the GND fill zone. Just take a good look at the rendering they show you! Fun fact: @acadiel's very first cartridge PCB: he left solder mask zone covering the edge fingers. protopcb gave him a free do-over, if I recall. 1 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 28, 2023 Author Share Posted November 28, 2023 Thanks for the advice. My KiCAD (v6) has no "bug" icon. Had to look at my other computer with v5 in it. V6 uses a a checklist icon for the design-rules checker. I think I like v5's insect better. My board passed, no errors or warnings. The Here is a top view of my latest version, with copper zones: Aisler still gave me a minimum-clearance error, even though I backed the copper zone off, and their rendering did not show me anything that looked "off." I wonder if they meant around the mounting holes. Have to try that out. K-R. 1 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted November 28, 2023 Share Posted November 28, 2023 You might also try moving the copper on the cartridge port edge connector back 10-15 thousandths of an inch. They don't like it when things go right to the edge of the board. . . Another suggestion is to bevel the corners of that card edge connector just a bit, as it will go into the cartridge port a lot more easily that way. 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted November 29, 2023 Share Posted November 29, 2023 you only have to worry about import duties if it's over $600 USD of product if I recall correctly. When I did multiple runs of F18A boards, i remember when I purchased the FPGA's over seas I had a pretty good import duty on them as it was over the $600 mark. 1 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 30, 2023 Author Share Posted November 30, 2023 (edited) On 11/27/2023 at 9:38 PM, Ksarul said: You might also try moving the copper on the cartridge port edge connector back 10-15 thousandths of an inch. They don't like it when things go right to the edge of the board. . . Another suggestion is to bevel the corners of that card edge connector just a bit, as it will go into the cartridge port a lot more easily that way. Thanks for the advice; had not thought of either of those. The edge connector might be the clearance violation. K-R. Edited November 30, 2023 by Kchula-Rrit Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted November 30, 2023 Author Share Posted November 30, 2023 5 hours ago, Shift838 said: you only have to worry about import duties if it's over $600 USD of product if I recall correctly. When I did multiple runs of F18A boards, i remember when I purchased the FPGA's over seas I had a pretty good import duty on them as it was over the $600 mark. Good to know. Come to think of it, I do not recall any import duty on some reels of PLA filament. I guess that first incident really got burned into my mind. Some parts I ordered from Canada cost $35 and the duty was $50. Admittedly, it was some time ago... K-R. Quote Link to comment Share on other sites More sharing options...
+acadiel Posted November 30, 2023 Share Posted November 30, 2023 On 11/27/2023 at 9:59 PM, FarmerPotato said: Another tip about PCB houses: they will have design rules -- for instance minimum distances between thru-hole and fill or mask. This is what the "Bug" tool checks. (DRC) The PCB house will run a DRC too, but after making sure that THEIR minimums are applied. If you didn't change any of the KiCad defaults and the PCB house didn't report any problems, you're probably ok. I got in trouble where I raised the minimum clearance between trace & thru-hole for GND net. What rendered on my screen was different from Aisler's board rendering--specifically the GND fill zone. Just take a good look at the rendering they show you! Fun fact: @acadiel's very first cartridge PCB: he left solder mask zone covering the edge fingers. protopcb gave him a free do-over, if I recall. Hehe... yep. I forget what the issue was in ExpressPCB, but yes, they did give a half-price do-over. I still have some of those that I sanded down and they still work just fine. That's why I got the next couple of runs of the 64K board with them before switching over to the local place for the last run of the 64K board. 3 1 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted December 29, 2023 Author Share Posted December 29, 2023 Boards just arrived from Aisler! They look really good; tried to photograph one, but couldn't get the picture to turn out. The edge-connector was apparently the clearance violation. At Ksarul's suggestion I backed the fingers off from the very edge and their checker passed the board. The corners on the finger-extension have a 1/16-inch radius on them, as well. They look like the picture above, except for the radius on the corners of the edge-connector. There were some "things" on the edge of the board where it looked like they were cut from a larger batch. After I filed them down the edge-connector plugged into my Tortise console quite nicely. The console's connector left some tracks in the "console goo" pretty much in the center of each finger. I'm happy so far. Now I can try some ideas I have for my "Delusion of Grandeur" cartridge, with a breadboard. K-R. 1 Quote Link to comment Share on other sites More sharing options...
Stuart Posted December 29, 2023 Share Posted December 29, 2023 8 hours ago, Kchula-Rrit said: There were some "things" on the edge of the board where it looked like they were cut from a larger batch. After I filed them down the edge-connector plugged into my Tortise console quite nicely. Your boards, plus boards from others, are arranged on standard size panel(s) which are processed through the machinery, then the inidividual boards are cut out from the panel. 1 Quote Link to comment Share on other sites More sharing options...
Kchula-Rrit Posted December 30, 2023 Author Share Posted December 30, 2023 15 hours ago, Stuart said: Your boards, plus boards from others, are arranged on standard size panel(s) which are processed through the machinery, then the inidividual boards are cut out from the panel. That makes sense; they aren't going to go through all that set-up just for my little boards. Fascinating that they had enough other orders to put mine in the pipeline right away. Here's a picture of the finished board: Shift838's board is much nicer, but this is my first attempt. Thanks for all the advice. K-R. 2 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.