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acadiel

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Everything posted by acadiel

  1. Great planning and thought put into this! I wasn't aware of it all earlier in the thread, so thanks for the explanation. Yes, I'd want my Pi Zero to have a jack in the back with separate power - to keep it running even when I turn the console off. Hard shutoffs for these things are hard to tell if you'll corrupt something - I have managed to corrupt Raspbian on a couple occasions where the kids yanked the RetroPi power out - and I just had to reimage it and move everything over again. The Zero takes minuscule voltage anyway, so I don't mind leaving it on. I wonder if a microUSB connector we can mount on the back of the case (like this) - or maybe, I can just do a Coax to microUSB and give it power externally that way. Both of these solutions - just drill a hole in the back.
  2. You could cut the power trace and put a DC in jack at the back of the speech case for the Pi. The only thing about the speech synthesizer is that it would have to go first in the chain to get power. The synth wouldn't pass any power anyway unless you've done the bypass mod, and paranoid folks could put a diode in place.
  3. I really want to make a sidecar passthru one day so plug a PEB card like this into. I’m thinking of a way around the regulator bypass issue. We can put a switch in new home brew PEB cards that would bypass the regulator and let you use an external PSU. When bypassed, plugging it in the PEB would just make it a dead card because it’s not getting any power from the external Jack. It wouldn’t blow anything. When not bypassed, it goes through the regulator like normal and the DC in Jack wouldn’t matter and be bypassed. We can even have standard instructions to adapt regular cards for this so folks could use them plugged into the sidecar passthru. I’m sure the above idea has holes in it, but I’ve been mulling it over for a while....
  4. They make them 3D printed now. These are notorious for cracking. https://www.shapeways.com/product/CMBQ6D2Z4/alps-x-y-plotter-gear-qty-3-commodore-atari?li=shareProduct Edit: These were the brass ones people were talking about at one time: http://www.xtreme-production.com/xtreme/index.php?main_page=product_info&cPath=159_307&products_id=3013
  5. Yep, I got your email... see above. Atrax and Arcadeshopper can take care of ya. Thanks!
  6. This might be something we can recreate the logic for to create reproduction CRU banked carts with current PAL/GALs. The CRU writes are pretty simple. We'd just have to figure out DBT's pinout on the cartridge (what they have hooked to where). I did pinout the TI Workshop cart at one time (earlier in this thread) - I have no idea why it had all almost all the cart address lines on it for the PAL, but I'm gathering it only manipulated three of them.
  7. Ksarul bought hundreds of the Hexbus chips. I forgot the exact number.
  8. Yeppers! That's what I was referring to above. Ksarul has most of the copies of the /4A interface. We also have schematics for the Hexbus drive controller. Edit: These are the only pictures I have of the interface. Ksarul will need to provide any higher resolution ones we need. He also has tons of the Hexbus interface chips he got as surplus. I do see a PAL. I do have the ROM dumped (attached). hexbus_interface.BIN
  9. I know Ksarul has a lot of the /4A Hexbus prototypes (and I have the ROM for one of them). But, has anyone thought about seeing if we can maybe put one of these in a sidecar for the JediMatt board? It would be kinda cool to use these to use Hexbus peripherals, connect to a CC-40 or TI-74, etc. I'd be willing to partner with someone on it - but we'd need hires pics of the Hexbus sidecars in existence.
  10. Was a rom for it ever released? That would be fun to play!
  11. Door Door. Someone did a ColecoVision port of it, I believe. I can't find the video offhand. Edit: Here it is:
  12. Yep, just got some 2532A's from them!
  13. The speed is much faster. The standard For X=1 to 10000;print x loop runs much faster. We have the hex dumps for the roms. At least the 32K ones. I don’t know if source exists. I’ve spoken with all four parties that programmed the ROM software. Three do not have the source. The fourth is not sure what they have, and won’t know until they go back home (from their second Vacation home) in June. And yes, it’s stripped down. All screen character definition, color, and sound is taken out. There is added PEEK, POKE, and MHCL (execute machine language) instructions. I’m sure if someone disassembles they rom, they can compare the BASIC tokens to the 99/4A. If someone has any thoughts on solving why the unit can’t stand the mic and earphone plugs being plugged in at the same time, l’m all ears. I keep getting an Internal Error when I have both plugged in to the battery operated cassette.
  14. The 99/2 seems to do that every time.
  15. Saving to cassette on the 99/2 and attempting to load on the 99/4A.
  16. I didn't phrase my question correctly. If this port is like the /4A's expansion port, the address space of >6000->7FFF is already decoded there. You simply have to hook a SRAM up to the address pins and the data pins. I wonder if they did this on the 99/2's expansion connector as well to keep the component count for cartridges low - if they already pre-decoded the address space, they could just plop a ROM on a PCB and get away with no chip select logic. Edit, I found some notes here from one of the technical manuals. However, these tech manuals were written at a time when this was a 12K ROM unit, not a 32K ROM unit. We have 4K RAM, so the whole of >E000->EFFF is 4K of RAM. The picture below assumed 2K of RAM, so >E7FF downward would be counted as RAM, down to >6800. That tells me the 32K "expansion" they originally wanted on the expansion bus (>6800->E7FF). However, since they added the extra 2K of internal RAM, does that mean only 30K can be on the expansion bus? (>6800->DFFF)? Or, can it continue to "count down" two more kilobytes to be 32K from >6000->DFFF? Anyway, I have the card edge connector and the 32K SRAM. I just need some help designing a circuit if I do need to decode any address space here. I figure we could start simple and just plop the whole 32K down from >6000->DFFF and see what happens. There's nothing in that space anyway. The last system ROM is located at >4000->5FFF.
  17. Here is my best effort pinout for the 99/2, according to the schematic. I've already found that the power supply (pre-regulator side) for the schematic is not accurate for my system (the schematic shows an AC supply - I most definitely have an AC supply that is regulated down to 5V, and needs 7V DC minimum to get the regulator to run). Seeing the 15V pins (33 and 34) that really aren't hooked to anything else makes me wonder if the 99/2's original PSU was a 15V supply, regulated down to 5V. (I've been running 7.5V on mine without issue.) I wonder how to properly plop a 5V 32K SRAM memory chip on this expansion bus. In other words, does the >6000->DFFF space exist on this expansion board? Anybody want to take a guess? PIN NAME 1 GND 2 GND 3 GND 4 GND 5 DCIN (5V) 6 DCIN (5V) 7 DCIN (5V) 8 DCIN (5V) 9 DCIN (5V) 10 DCIN (5V) 11 HORSYNC 12 COMP VIDEO 13 A8 14 A7 15 A6 16 A5 17 A4 18 A3 19 A2 20 A1 21 CRUOUT/A0 22 A9 23 NC 24 NC 25 A10 26 A11 27 A12 28 A13 29 A14 30 A15 31 D7 32 D6 33 15V 34 15V 35 D0 36 D1 37 D2 38 D3 39 D4 40 D5 41 CRUIN 42 CLKOUT 43 ROMEN 44 RESET IN 45 INT1 (low) 46 HOLDA 47 HOLD (low) 48 DBIN 49 MEMEN 50 W/CRUCLK (low) 51 RESET (low) 52 READY 53 NMI 54 CRTC CLK 3.35MHZ 55 VERSYNC 56 VIDEN 57 GND 58 GND 59 GND 60 GND (Left rear of unit) (Right rear of unit) TOP OF UNIT +-------------------------------------------------------------------------------------------+ | 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 08 06 04 02 | | 59 57 55 53 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 09 07 05 03 01 | +-------------------------------------------------------------------------------------------+
  18. I just dumped my 4K BSM (thanks, Bob!) Here's the binary. It's different from Ksarul's binary. bsm_jon.bin
  19. A question for Michael Zapf about the 99/2 emulation: If we give the emulation 32K of RAM from >6000 to >DFFF, would the system would recognize all of it? We can do that standard A=A+8 test to see if it does. That'll be a good indication if we put the 32K chip between >6000 and >DFFF on a real system how it'll expand the RAM or not.
  20. Would these work? https://vetco.net/products/60-pin-card-edge-female-connector
  21. More close up photos. Tons of detail.
  22. Here is the dead bug reference For the bank switched >4000 ROM. The Test points circled in the diagram are defined on the top (CF40058 chip) and the connections to the 74Ls139N are noted in the bottom box. Note: CF40058 is likely the I/O chip. The only documentation available is for the CF40051, likely an earlier model. The CF40051 shows pin #18 (TP1) being "S0/Keyboard Scan" and pin #20 (TP2) being "CRUCLKB (CRU Clock)." How those play into bank switching, I don't know. I do know that TP3 is a chip enable that will enable or disable that top EPROM. I'm guessing that one of the cut traces goes to the bottom EPROM's chip enable, but I haven't metered that yet.
  23. Stay tuned in this thread for a bunch of TI-99/2 information. Ksarul knows what I'm talking about... In the meantime, here are some tidits: I am in possession of TI-99/2 unit #115. This unit was originally going to be a Canadian demo unit, and is a almost production ready TI-99/2 The unit has 32K of ROM (attached), which Michael Zapf has confirmed is the same exact dumps as Klaus' 32K ROM The system was originally supposed to have a 24K ROM (three EPROMs). There is a 74LS139N logic chip installed 'dead bug' to enable bank switching at >4000 for 16K of the System ROM (8K at a time.) I do have the pinouts of how this chip is hooked up. I'll have to scan them. The earliest specs for the computer said it would have 12K of ROM. The unit had two problems with it when I got it: 1) One of the bank switched >4000 ROMs was 'empty' - the TMS2564 voltage pin wasn't working, showing a null ROM. Jumping bad pin 28(VCC) to 26 (also VCC) activated it. I programmed a new TMS2564 and installed it with the original sticker. 2) The coupling 100nf glass capacitor near the power supply entry was shattered. I bought a lot of 104 caps on eBay and installed a NOS one to keep the system authentic. The system can run just fine off of a 7.5v, 2.5A DC power adapter. The schematics for mine originally showed an AC PSU, but this most definitely uses a DC PSU, and has a 5V regulator inline. The OLD CS1 and SAVE CS1 work just fine. I was able to save and load to cassette. The TI-99/2 does NOT tolerate stereo patch cables. Use a mono one for both in/out The system appears to have 4K of RAM. If we can find a female cartridge connector, we might be able to PCB a RAM expansion. We just have to figure out how much RAM the system will support in total. The Memory map looks like this: >0000->1FFF - System ROM >2000->3FFF - System ROM >4000->5FFF - System ROM (bank switched) >6000->DFFF- My guess is that cart RAM/ROM expansion might live here (32K) >E000->EFFF - System ram (4K)? >F000->FFFF - Processor RAM and unused according to the memory map The system has two custom IC's - CF40058 and CF40059. These handle the Video Display Controller and I/O. However, existing documentation for this system shows these two have different part numbers, CF40051 (I/O) and CF40052 (VDC). I don't know which is which, but my guess is the 40059 is video (below the 9995) and 40058 is the I/O, because the dead bug for bank switching should be connected to the 40058. Anyway, stay tuned to this thread. I have some surprises coming. jons_992_correct.zip
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