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Ksarul

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Posts posted by Ksarul

  1. Posted

    It's one of the earliest ones they made too--as those had the tan/brownish clamshells. Later they switched to black, and the last ones didn't have a clamshell at all. I seem to remember that there was an issue with the FDC chip in the first batch they built--the chips were from a lot that had some serious QC problems and they switched them out with a daughter board with a different FDC chip on it due to a temporary shortage of the original chip. They then just stayed with the substitute and incorporated it directly into later boards.

  2. Posted

    The project you are asking about is the project you're looking at in this thread, Manic1975. Tursi, Acadiel, and I have been working on this off and on for a few years now. The cartridge is a two-part system. Part one is ROM. That part is banked in 8K increments using non-inverted banking. The second part (the GROM simulation code for the AVR) allows up to 128K of GROM on the cartridge (giving a maximum of 640K of program space on the cartridge). Note that only the AVR can be programmed over a USB port, but that Tursi plans a loader that will load the AVR from the TI.

     

    The memory that is reprogrammable is limited by the AVR being used, an ATMEL ATMega1284. We used that because it is the largest DIP AVR available, and most TI users really don't like to deal with surface-mount stuff. If ATMEL comes out with a larger DIP AVR that is compatible with the ATMega series (likely name would be a 2564), it should work too, but I really don't see that happening.

     

    You might also look at the 632K cartridge thread, as that is Gazoo's plan to load up one of these boards with software. . .he uses 8K for the menu.

  3. Posted

    I actually have an Aquarius as well--but then I also have a Powertran Cortex, a Tomy Tutor, a Tomy Pyuuta, a Tomy Pyuuta Jr., a Tomy Pyuuta Mark II, a TI CC40, A TI74, a Kaypro IV, a Sage II, and a Marinchip S9900 (all of these in addtion to my regular TI machines: a 99/4, a 99/4A, and a pair of 99/8s (one of each major type for the 99/8s).

  5. Posted

    I finally got a chance to go through the last of my recent TI purchases (wouldn't you know it, the thing I was looking for was in the LAST box I checked). I did find an Editor Assembler cart (just the cart, no manual, but you can find the manual online at the WHT FTP site). Let me know if you still need one UK Retrogamer and we can work something out. . .

  9. Posted

    I'll do the dip selector for sure, Marc--and for the clock chips, right now I have it set up so that you put whatever chip you want in the socket and jumper each pin across to the appropriate signal on the board. It would require up to 40 jumpers to connect the clock--but it is also pretty much future-proof, as any DIP clock chip can be put in there. . .I'll look at the one you suggested too, Swim. Again, many thanks for the input.

     

    Gazoo, I'm not sure I'll have room to put a CF socket on there--but I'll look at the idea. Doing so might enlarge the rear extension of the card too much for stability Personally, I'd also avoid moving power to pin 20 on the connector, but I'll think about doing that too--or at least setting up a jumper for it.

    • Like 1

  12. Posted

    I've already set up a spot on near the connectors to connect a 4-pin power plug of the 3.5" floppy-drive style, Swim. I also put two connectors so that it would be easy to attach a CF adapter at the back and still have a place to attach an IDE cable for a second drive. Note they are on the same IDE bus, so the maximum number of devices is still two for the card.

     

    The area for the clock is still in flux, so any useful ideas here can still be implemented (with a greater or lesser degree of ease, depending on the chip). Many thanks for the input--I definitely can use the help! :)

    • Like 1

  13. Posted

    I have been working on this one again--I've actually gotten things to the point where I'm about halfway done with the layout and have a way forward for most of the rest. One thing I've been mulling over is to put a larger socket in for the various clock chips with connections to a double row of pins next to it. This would allow us to insert pretty much any clock chip that we think would work and then jumper across to connect the pins to the right signals. That part of the board would look like a wire nest, but it would then be super-flexible when it comes to the clocks. It does use less real estate on the board than setting up three separate clock sockets does. Thoughts anyone?

  18. Posted

    ROM development module, actually, Marc. Use it as RAM to write the test module to the space, write protect it, and run the tests as if it was a normal ROM. It is primarily a modification to speed up 32K cartridge development cycles when using real hardware instead of emulation. It is definitely not for standard use most of the time, as the NVSRAM won't fit in a closed cartridge case without sawing a hole in the top of the case. I suppose it would also work for folks wanting to load existing cartridges up to 32K in size into it and running them as well. . .but that isn't the real reason we're thinking about this.

    • Like 2

  20. Posted

    Actually, the ZIF will only work to allow you to insert ROM-only cartridge files (and depending on the board it is installed on, it may work with 8K, 16K, or 64K ROMs--with all of the ones larger than 8K being bank-switched). This won't help with your E/A issue, however, as the file needs to be stored on a GROM, which is a specialized TI chip with its own internal address bus that auto increments when polled to present the next instruction. These can be simulated, but it takes a lot of external logic or an AVR. Is your board one of the ones produced by Hexbus? It will have a 74LS379 on it in addition to the ZIF socket (and a couple of resistors/capacitors). I haven't been through my spares box yet, so I still don't know if I have an extra E/A cartridge. One note--if you have a DataBioTics SuperSpace cartridge, a Pilgrim's Pride 6000+ module, or a Supercart (Supercarts were usually homebrews, but some were made in quantity as user's group projects), each of them has an E/A module GROM in it as well.

     

    I'm part of a team that has a GROM-simulation capable cartridge board nearly ready for prime time. The last bugs on the hardware side have finally been quashed and the software for the AVR is done as well--now we just have to polish up the last details in the developer's manual a bit and it will be done.

  21. Posted

    I think we have that covered, Marc--if the WE* signal to the SRAM is held high (and it will be when the switch disables it, as it will then be providing +5V on WE*), the board should respond the same way as it would with an EPROM. We would need a loader that makes sure its last action before exiting is to verify that the header bits are undamaged though. If you have some additional thoughts, feel free to join in--I'd rather work though the ramifications of any possible gotchas before I finalize the design.

     

    We should probably move this discussion to its own thread though. . .as it is an interesting topic in its own right.

  22. Posted

    If it does the same thing in WIN994A, it isn't an equipment problem. It is probably something really subtle in the code that will have you smack your head in disbelief once you do find it. I don't know enough Assembly to help more than this, I'm afraid, but I'm sure that one of the programming gurus will find it in short order.

     

    It sounds like it is about time for a relaxing brew! :)

  23. Posted

    After doing some careful datasheet comparison I found that these aren't a direct replacement for the EPROMs we use, as A14 shifts from pin 27 to pin 1. I was able to quickly modify the layout to incorporate both of the changes this difference required, however, so the problem only increased the complexity of the modification a little bit. To make it an elegant change, I changed JP1 and JP4 to three-way headers so that all necessary signaling changes are accomplished by setting just those two jumpers differently from their normal use position. If one wants to have the WE signal switched, just connect two wires to the appropriate jumper lines on J4, add a third wire to carry +5V and add the switch so you can toggle between WE and +5V. I made sure to place a clearly marked pad near JP4 to grab the +5V from. I didn't want to add it to the header to prevent accidental connections to the +5V during standard operations.

     

    This change was done to the V9 board template. I still have to do my final QC checks on it, but all of the necessary trace changes look to be right now.

  25. Posted

    The E/A works fine with a sidecar 32K (TI or third party) and a sidecar disk controller (TI or third party). You don't need the TI PEB for it. You can also use an Atronic CPS99, a CorComp 9900, or a Myarc MPES-50, as all of them have the same capabilities as a normal PEB.

     

    I passed my spare on to someone about a year ago. I'll have to look to see if I got one in the last couple of batches of cartridges I bought. . .

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