Announcement

Collapse

Forum Rules and Etiquette

Our mission ...

This forum is part of our mission to promote the preservation of vintage computers through education and outreach. (In real life we also run events and have a museum.) We encourage you to join us, participate, share your knowledge, and enjoy.

This forum has been around in this format for over 15 years. These rules and guidelines help us maintain a healthy and active community, and we moderate the forum to keep things on track. Please familiarize yourself with these rules and guidelines.


Rule 1: Remain civil and respectful

There are several hundred people who actively participate here. People come from all different backgrounds and will have different ways of seeing things. You will not agree with everything you read here. Back-and-forth discussions are fine but do not cross the line into rude or disrespectful behavior.

Conduct yourself as you would at any other place where people come together in person to discuss their hobby. If you wouldn't say something to somebody in person, then you probably should not be writing it here.

This should be obvious but, just in case: profanity, threats, slurs against any group (sexual, racial, gender, etc.) will not be tolerated.


Rule 2: Stay close to the original topic being discussed
  • If you are starting a new thread choose a reasonable sub-forum to start your thread. (If you choose incorrectly don't worry, we can fix that.)
  • If you are responding to a thread, stay on topic - the original poster was trying to achieve something. You can always start a new thread instead of potentially "hijacking" an existing thread.



Rule 3: Contribute something meaningful

To put things in engineering terms, we value a high signal to noise ratio. Coming here should not be a waste of time.
  • This is not a chat room. If you are taking less than 30 seconds to make a post then you are probably doing something wrong. A post should be on topic, clear, and contribute something meaningful to the discussion. If people read your posts and feel that their time as been wasted, they will stop reading your posts. Worse yet, they will stop visiting and we'll lose their experience and contributions.
  • Do not bump threads.
  • Do not "necro-post" unless you are following up to a specific person on a specific thread. And even then, that person may have moved on. Just start a new thread for your related topic.
  • Use the Private Message system for posts that are targeted at a specific person.


Rule 4: "PM Sent!" messages (or, how to use the Private Message system)

This forum has a private message feature that we want people to use for messages that are not of general interest to other members.

In short, if you are going to reply to a thread and that reply is targeted to a specific individual and not of interest to anybody else (either now or in the future) then send a private message instead.

Here are some obvious examples of when you should not reply to a thread and use the PM system instead:
  • "PM Sent!": Do not tell the rest of us that you sent a PM ... the forum software will tell the other person that they have a PM waiting.
  • "How much is shipping to ....": This is a very specific and directed question that is not of interest to anybody else.


Why do we have this policy? Sending a "PM Sent!" type message basically wastes everybody else's time by making them having to scroll past a post in a thread that looks to be updated, when the update is not meaningful. And the person you are sending the PM to will be notified by the forum software that they have a message waiting for them. Look up at the top near the right edge where it says 'Notifications' ... if you have a PM waiting, it will tell you there.

Rule 5: Copyright and other legal issues

We are here to discuss vintage computing, so discussing software, books, and other intellectual property that is on-topic is fine. We don't want people using these forums to discuss or enable copyright violations or other things that are against the law; whether you agree with the law or not is irrelevant. Do not use our resources for something that is legally or morally questionable.

Our discussions here generally fall under "fair use." Telling people how to pirate a software title is an example of something that is not allowable here.


Reporting problematic posts

If you see spam, a wildly off-topic post, or something abusive or illegal please report the thread by clicking on the "Report Post" icon. (It looks like an exclamation point in a triangle and it is available under every post.) This send a notification to all of the moderators, so somebody will see it and deal with it.

If you are unsure you may consider sending a private message to a moderator instead.


New user moderation

New users are directly moderated so that we can weed spammers out early. This means that for your first 10 posts you will have some delay before they are seen. We understand this can be disruptive to the flow of conversation and we try to keep up with our new user moderation duties to avoid undue inconvenience. Please do not make duplicate posts, extra posts to bump your post count, or ask the moderators to expedite this process; 10 moderated posts will go by quickly.

New users also have a smaller personal message inbox limit and are rate limited when sending PMs to other users.


Other suggestions
  • Use Google, books, or other definitive sources. There is a lot of information out there.
  • Don't make people guess at what you are trying to say; we are not mind readers. Be clear and concise.
  • Spelling and grammar are not rated, but they do make a post easier to read.
See more
See less

Powertran Cortex

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    I'm looking for a supplier to make some double sided PCBs.. does anyone know or can recommend a reputable company ?

    I've been told that you can get a good quality 300mm x 160mm Double sided board for 15 each, though you have to order min 10 boards !

    Comment


      Originally posted by ti99/4a View Post
      With a bit of Tweaking it could be modified into a Tomy Tutor ??
      I guess once the F18A is added it is reasonably close to a Tomy Tutor, minus the keyboard, joystick, printer and cassette interfaces. Also, the locations of memory mapped I/O devices are different. I think your biggest hurdle will be to find good schematics and ROM images of a Tomy Tutor, but with that in hand the "tweaking" should be doable.

      It also depends whether you want to use Tomy software unchanged or are able to tweak the software. In the latter case, less tweaking of the hardware is needed. in the former case, you might be better of doing an exact copy of the Tomy Tutor, only changing the 9918A for an F18A.

      I think it will be a several more weeks before I have finalised the mini-cortex design and tested the circuit on the bread board: as-is it is not a 'confirmed working' schematic, let alone a confirmed working PCB.

      Comment


        ROM images for the Tutor are widely available. What is not well-understood is how the banking logic in the CLA works, and there are some locations at >EExx that do "magic" no one has fully documented yet.
        I use my C128 because I am an ornery, stubborn, retro grouch. -- Bob Masse
        Various projects and oddities: http://oldvcr.blogspot.com/
        Machine room: http://www.floodgap.com/etc/machines.html

        Comment


          Hello friends, i am a TI99 user.. i looked last summer a real powertran cortex and looked that is more near at my computer. i start at use the emulator and i wont try at learn a basic.. now i have a problem.. i used emulator v2.0, and i load a dump disk image with a basic program.. exist a mode for print a listate or extract the file in ascii mode for read it and print? I no have a real powertran in Italy is more rarest
          thanks Ermanno

          Comment


            Originally posted by ti99/4a View Post
            I'm looking for a supplier to make some double sided PCBs.. does anyone know or can recommend a reputable company ?

            I've been told that you can get a good quality 300mm x 160mm Double sided board for 15 each, though you have to order min 10 boards !
            Ksarul put me onto www.sitopway.com, who I've used three times now, and couldn't be happier. Have ordered the boards with green soldermask and white silkscreen. Turnaround is 5 days. No minimum quantity as far as I'm aware - I've only ordered around 3 of each board.

            No online quote tool like some of the other PCB manufacturers, but send a copy of the gerbers plus spec and quantity you need to [sales@sitopway.com] and they'll get back to you with a quote within 24 hours or so. For both the orders I've placed, have also received an extra 1 or 2 of the boards free. Not sure if that's just a teaser for a new customer, or extras they managed to squeeze onto the larger manufacturing panel.

            Stuart.

            Comment


              Originally posted by astharot View Post
              Hello friends, i am a TI99 user.. i looked last summer a real powertran cortex and looked that is more near at my computer. i start at use the emulator and i wont try at learn a basic.. now i have a problem.. i used emulator v2.0, and i load a dump disk image with a basic program.. exist a mode for print a listate or extract the file in ascii mode for read it and print? I no have a real powertran in Italy is more rarest
              thanks Ermanno
              Hi Ermanno. You want to be able to list a BASIC program to a text file on the PC? It's possible using the serial terminal feature of the emulator, but takes a couple of steps:

              (1) Load the program into the emulator.
              (2) In the emulator, select Terminal > Serial Terminal from the menu. This should display a second window.
              (3) Select Terminal > Start Terminal Log from the menu. This will display a Windows file dialog where you specify the file to list the program to. By default the file will have a .trm extension, but it's just a plain text file.
              (4) At the Cortex prompt in BASIC, type UNIT 2<Return>. Everything that appears on the screen will now also be sent to the serial terminal window. And everything sent to the serial terminal window will be captured in the log file.
              (5) At the Cortex prompt in BASIC, type LIST<Return>. You should be able to work out what's going to happen.
              (6) Select Terminal > Stop Terminal Log from the menu. The plain text log file now contains the program listing.
              (7) Typing UNIT -2<Return> at the BASIC prompt will stop output going to the serial terminal window.

              I'm expecting someone to point out a far easier way to do it that I've missed!

              Stuart.

              Comment


                Stuart PERFECT!!!!! Write your solution in software section that i have created GREAT BOSS!!!

                Comment


                  On Sitopway, I've made something in the vicinity of 20 orders from them, and most of them have a few "spares" in the order. I've only twice had a board that was actually bad though (out of about 1,000 boards), so the spares are almost always that--a nice extra bit that just makes this board house that much better in my eyes.
                  Enter My Mind At Your Own Risk!

                  Comment


                    Gentlemen,

                    Herewith revised schematics and PCB for the Mini Cortex.

                    I think I've reflected all feedback, from CRUCLK handling, to decouplers, to headers for other interface options, etc. I've also added a F18A to the design. Once again your constructive critique would be much appreciated.

                    The Mini Cortex should be able to run the following software:
                    - Cortex Basic
                    - TurboForth
                    - Monitor
                    - MDEX
                    - Unix (up to full version 6)

                    Possibly, it can run NOS (harddisk version of MDEX) and TXDS (the OS for the TI990/4 mini). It won't run DX10. Possibly, it could run some Geneve software with a modest porting effort.

                    As a long term project it would be interesting to port INTERACT to the Mini Cortex.

                    Comment


                      Hi

                      Do you have a Bill of Materials (BOM) list and project costs /costings for your wonderful Mini-cortex ??

                      Thanks

                      Comment


                        Paul asked me to clarify a few details about the F18A, so here are the questions and answers:

                        1. Can the F18A can be hooked up to a 9995 without wait states?
                        A: Short answer, yes. The F18A's host-interface state machine needs about 120ns (worse case) between reads and writes. As long as the host CPU does not have a memory cycles faster than that, it should work fine. After checking the 9995 datasheet, it looks like the F18A should be ok with a 12MHz 9995.

                        2. There seem to be various versions of the F18A regarding pin size and board orientations?
                        A: The F18A is wider than the original VDP 40-pin DIP package, and hangs off the socket to the left side (the side with pins 1..20). That is currently the only orientation. I offer two PCB pin styles, short and tall, because when I went to install an F18A into a ColecoVision I noticed that the CV used rather tall capacitors around the DRAM chips. The F18A with short pins required those capacitors to be seriously bent over or removed, thus I found some taller PCB pins that would raise the F18A higher and allow it to fit better in systems with components near the VDP socket. There is no other difference. The tall pins are about as tall as a typical SIP pin header used in hobby electronics and on boards like the Arduino and such. Either way, I highly recommend the F18A be installed in a socket, and leave room to the left of the socket for the F18A profile.

                        3. The F18A could be a nice prototyping board for hardware floating point. Not sure how to reprogram the F18A, didn't see a JTAG header on the board.
                        A: The F18A comes with a JTAG header soldered to the board, however the photo on my web store does not show the header (I need to update those photos). You can certainly use the F18A as an FPGA devboard and I was hoping some people would do just that. It only needs 5V and ground to operate, has a simple 8-bit bidirectional bus, 12-bit VGA color, 1MB flash, and several I/O pins. You can develop HDL for it using the free Xilinx ISE WebPack software.

                        Comment


                          Originally posted by ti99/4a View Post
                          Do you have a Bill of Materials (BOM) list and project costs /costings for your wonderful Mini-cortex ??
                          I'll work on a detailed BOM. In brief the key parts are:
                          U1 TMS9995
                          U2 74LS612
                          U3 74LS14
                          U4 AT28C256
                          U5 628512-55
                          U6 74HCT688
                          U7 Sparkfun slim CF Card Board
                          U8 TMS9902A
                          U9 Elektor FT232R Board
                          U10 74LS259
                          U11 GAL22V10D
                          U12 74LS74
                          U13 74LS112
                          U14 74LS138
                          U15 F18A Board

                          Of the above the breakout boards are the most expensive: an F18A is about 75, and the other two are about 25 each. All together the Mini Cortex might cost as much as 200. If you leave out the F18A and use the cable Jim suggested instead of the Elektor board, it might come out at about 100. Obviously it all also depends on what you already have in your parts drawer, whether you source locally or from China, whether you make 1 or 10 PCB's, etc.

                          Forum member "lezanderson" has a lot of experience with component kits, perhaps he is willing to chime in with estimated costing for a Mini Cortex kit.

                          Once again, please be aware that this design is unproven as yet. I strongly recommend that if you want to build this you wait until a prototype has been built and is confirmed working.

                          Comment


                            Since a 512K x 8 static ram chip is not much more expensive than a 64K x 8 chip, would you make the PCB able to take either chip, perhaps 2 chips giving either 128KB or 1MB maximum.
                            Even the Sinclair Spectrum had 128KB ram, and the Cortex was designed to be expandable to 1MB.

                            Comment


                              Originally posted by mnbvcxz View Post
                              Since a 512K x 8 static ram chip is not much more expensive than a 64K x 8 chip, would you make the PCB able to take either chip, perhaps 2 chips giving either 128KB or 1MB maximum. Even the Sinclair Spectrum had 128KB ram, and the Cortex was designed to be expandable to 1MB.
                              I forgot to provide a circuit description, sorry: the 628512 is a 512K x 8 static ram chip. There is no room on the PCB for a second ram chip. Even if there were, I'm using one line of the '612 mapper to be a flag to mark a memory page as read only, leaving only 19 address lines = 512KB. This is a deviation from the Cortex design which has a use for Unix (shared memory pages, making 'fork' operations much faster).

                              Are there applications that would benefit from having 1MB of ram?

                              Comment


                                Originally posted by matthew180 View Post
                                The F18A is wider than the original VDP 40-pin DIP package, and hangs off the socket to the left side (the side with pins 1..20).
                                Ah, somehow I convinced myself it was extending to the right. On the left it will have to clear the CF Card breakout board. How long are the long pins? About 10mm?

                                Originally posted by matthew180 View Post
                                You can certainly use the F18A as an FPGA devboard and I was hoping some people would do just that. It only needs 5V and ground to operate, has a simple 8-bit bidirectional bus, 12-bit VGA color, 1MB flash, and several I/O pins. You can develop HDL for it using the free Xilinx ISE WebPack software.
                                That is great news! Do you have a suggestion for a USB-JTAG cable to use?

                                One last question: I believe you build the boards yourself, do you have a good home technique for mounting SMD parts? I am considering to have the CF Card socket directly on the main PCB, but I do not look forward to soldering 0.025" spaced leads by hand...
                                Last edited by pnr; March 18, 2015, 02:55 PM. Reason: typo

                                Comment

                                Working...
                                X