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About FarmerPotato

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  • Birthday 01/01/1971

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    Austin, TX
  • Interests
    TI-99/4A. FORTH. Verilog.
  • Currently Playing
    Last year: Port Royale 3, Pocket Trains, Minecraft, Master of Orion II, PacMan 256, Katamari Damacy, We Love Katamari, NY Times Crossword
    This year: Katamari Damacy Reroll, Settlers of Catan Universe, Chisholm Trail, NY Times Crossword

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  1. Hackerspace work night report: We tried out Zoom at the Hackerspace. Amanda installed the Zoom app on a Galaxy 10 phone. That's our camera/mic. Using wifi and DC power. The picture was good in the classroom lighting. Sound was ok. I think I can scrounge up a Bluetooth headset. There will be a tripod for the camera. With Zoom, you can do screen sharing, or yield the sharing privilege to others. To join in with Zoom (in August!), use the meeting ID https://zoom.us/j/7707370625 The projector in the classroom is history. There is a projector in the lounge, but it's set up for playing video games from the couch. The classroom has a 60" LCD with all the inputs (RF,VGA,HDMI,Composite) and another 37" LCD. There are two huge whiteboards on one wall. Danny was doing air conditioning maintenance last night. So it should be running at tip top. We also have big-ass fans (not actually those ones) A couple Hackerspace members expressed interest in attending.
  2. Me too on the waitlist for 1. I'm not in a hurry. I'm currently working on side port and cartridge port. No immediate plans for Pbox.
  3. Welcome bcombee! There will be lots to see. We'll be happy to share the knowledge of whatever aspect of 4A-ness you want. Feel free to bring your system to work with, there will be plenty of space in the classroom. acadiel and OLD CS1 were at VCFSW too.
  4. Hello, I'm attempting to use the ATF22LV10C-JU with the new model XGPro programmer (formerly MiniPro, TL866-II). What I've tried: I have a PLCC-28 to DIP28 adaptor, and program it as DIP28. The programmer reports success at each step. However, I've received my PCB, begun board bringup, and I'm not getting anything out of the PLD. JED file is from WinCUPL, where the design simulates successfully. I verified VCC=3.3, and CLK in at 6 MHz. All inputs are stepped down to 3.3V by 74LVC245A buffers, and much slower than 3 Mhz. I have only combinatorial equations, no registers, but I put a 6 Mhz on the CLK pin anyway. So far, all I see is two Output pins at 3.3, when they should be varying. I didn't add enough test points to my board, so I've ordered a custom PCB breakout to test the ATF22LV10 in isolation. Others reported the ATF22V10 wasn't easy to program. My XGPro with the latest firmware reports success, is there any reason to be skeptical of this?
  5. It's almost the 3rd Wednesday work night at ATX Hackerspace, Jul 16. I'll be there doing some 99/4ATX business. Like trying out video conferencing in the classroom, with YouTube and Zoom. In case you want to test being on the Zoom channel, here's the URL: Zoom meeting URL: https://zoom.us/j/7707370625 I'm not sure if you have to sign in on Zoom. Anyway its free. YouTube test channel to follow. Anybody is welcome to jump in Wednesday night after 7:30 Central. Thanks for all the input on which videoconference.
  6. I'm in the 24hr wait period for YouTube. I like Zoom and it has chat and screen sharing. It turns out it only costs $15 for a one month plan. The free one cuts off every 40 minutes. My new Zoom meeting URL: https://zoom.us/j/7707370625
  7. Has anybody made (for sale) a test point adaptor for Pbox card, sidecar, or cartridge port? I've seen pictures of a Pbox card riser with a card on top. Ideally there would be a row of pin headers to attach probes to, so that you can watch the bus without adding test points for all the common signals to hardware under development. I drew up a PCB for the cartridge port, 3" long and 2" wide (just a bit wider than the 2x18 card edge.) It takes a 2x18 header for test leads, and a pass-thru 4A cartridge port (either pointing up, or reuse the right angle adaptor.) I'm kind of balking at the fab cost which is the same as a regular cartridge run. Ideas to make it more useful would be to squeeze in some pads for GROM, EPROM, bank latch, and maybe even a tiny prototype area. So it becomes both a cartridge debugger AND an experimenter board. Test points board. 50mm wide x 75 mm long. ||||||||||||||| -|||||||||||||||- ||||||||||||||||| ||||||||||||||||| ||||||||||||||||| ||||||||||||||||| ||||||||||||||||| |***************| test point |***************| headers ||||||||||||||||| ||||||||||||||||| |@@@@@@@@@@@@@@@| cartridge port \@@@@@@@@@@@@@@@/ pass-thru Experimenter add-on board. 50mm wide x 100mm long. ||||||||||||||| -|||||||||||||||- | | |LLLLLL GGGGGG | LATCH and GROM socket |LLLLLL GGGGGG | | | |RRRRRRRRR | EPROM socket |RRRRRRRRR | |RRRRRRRRR | | | |***************| breakout all pins |***************| in rational order |...............| protoboard |...............| |...............| . . |...............| |...............| |...............| Two boards can be panelized in a 100x100mm job ($16.95 at dirtypcbs.com), two for the price of one. Here's another inspiration for an experimenter board: https://store.digilentinc.com/breadboard-expansion-with-mxp-connectors-for-ni-myrio/
  8. I will try YouTube. There's no two-way there, no chat room right?
  9. Video Broadcast for 99/4ATX on weekend of Aug 8-10! We will have a Ustream channel. When no one wants to broadcast on it, it will point at something interesting, like a computer demo, a 3D printer, or a breakfast taco. You never know! https://www.ustream.tv/channel/u45p8uc7YSS I picked Ustream because the free trial seems better than freeconferencecall.com or Zoom.
  10. Making the RAM fast and large is a perfectly fine goal, it's just not possible on the cartridge port. 9900 doesn't need cache because its clock is only 3 MHz and cheap SRAM even from the late 80s needs no wait states. Cache is a necessity when your CPU is clocked way faster than the RAM; today your x86 is clocked in gigahertz and your RAM at 800 Mhz. TheBF had some good ideas about replacing the side port with a 16 bit fast memory bus to the PBox (I hope with a backwards compatible adaptor as an option). Others have put fast 32K memory inside the console. We don't need a cache, we just need RAM in the console that is 16 bit and no wait states. Modern SRAM is fast and cheap. For instance, this 512Kx8 thru-hole SRAM is $5 and is the type used in SAMS cards (and hopefully future Horizon RAMdisk). And this 512Kx8 or 256Kx16 part is $3 and $5, operates up to 100Mhz, and comes in a surface mount package that is just a little harder to solder than plain old 0.1" thru hole chips (SOJ-36 with 0.05" pins, you need a magnifier, and a knife edge K solder tip.) It would be hellacomplicated but you could make an in-console 16-bit bus tiny SAMS upgrade around that. Then again, I have more ideas than time or attention span.
  11. I'm still waiting for the actual cart boards from DirtyPCBs (where they cost $2 each). I held it up until I added the peg hole into the board (oops). BUT I will have this test rig for the ATF22V10 logic chip from OshPark next week. I couldn't stand working with the PLCC to DIP adaptor that came with the TL866 / XGecu programmer. (It doesn't fit a breadboard, for one.) It it a PLCC-28 adaptor with two sets of pins: one set on the bottom plugs into a breadboard, while the top set is for a logic analyzer. All the pins on top are labeled. Carts through OshPark would cost $50 for 3! It's good for prototyping small things fast at $5/sq inch for three samples. (I screw up one while soldering, I get the next one working, maybe need the 3rd one after I break #2.)
  12. I think that considering a 512K flash cart as a big RAM is off the track. You could replace the chip with a large SRAM (for about $20) and have a mega-Supercart, but here are the numbers, like mizapf said: Relative Speeds (not including instruction overhead which is pretty big.) 1 PAD 16-bit access in 1 cycle each for read and write. 6 32K expansion 8-bit access in 6 cycles for read and write of 1 or 2 bytes. 2 x (1 cycle + 2 wait states). 6 times slower than PAD. 300 Flash - same read access as 32K, but takes 9 writes to program one byte. Plus a lot more instruction fetch and executes. So it will be at least 20 times slower than the 32K RAM per byte, or 40x slower per word. I'm guessing 50x after overhead. In other words, writing to Flash is best suited for saving small amounts of data or loading a new cart into the thing. I spent a lot of hours with the logic analyzer on the side port watching Mini Memory and 32k accesses. I know it pretty well by now. Tursi also made a great document from his logic analyzer of all types of memory cycles. I'll record the bus activity of the flash-writing code listed above to know for sure what the relative speed will be. (I have simulated my tests so far in the WinCUPL simulator from the Windows 95 era and I really, really have grown to hate it.)
  13. OK. We have a really nice Hakko desoldering vacuum gun and ChipQuik. Makes it a breeze. Bring a 40 pin socket.
  14. We can get one out of a scrap 4A for you. Otherwise it's about $3-$5 from China, $30 domestic. I forget whether it's soldered or socketed, but no problem, we can desolder at the Hackerspace.
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