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Powertran Cortex

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    Originally posted by Norv View Post
    Hi all
    My Cortex is still here looking for a good home, I don't think it helps that my posts seem to take up to a week to get past the moderator. By the time my posts get on the site you lot have moved on to the next page.
    I have no objections to it going to America or even further. I have a business address so it can be collected during the day by a courier.
    I have also found an a to d board that I don't think is quite finished and a few odd ic's (not 999 series) that can come with it.

    Norvin
    Is it just me or has anybody else only just had notification that this message was posted ?, i'm sure it wasn't there on the 27th when it says it was posted.

    I didn't think this forum was moderated, if you are registered the messages get posted straight away ?

    Jim

    Comment


      Originally posted by Jim Hearne View Post
      Is it just me or has anybody else only just had notification that this message was posted ?, i'm sure it wasn't there on the 27th when it says it was posted.

      I didn't think this forum was moderated, if you are registered the messages get posted straight away ?

      Jim
      I don't Know if it is a junior member thing but I am registered and it always takes about a week for my posts to get on the forum but when they do go up the seem to be inserted back in date order for the time I sent them. but never mind please don't forget about my Cortex where is it going. I am starting to get my ear bent about it so need to get it sorted. I am posting this at 18;00 uk time on 2nd December.

      Norvin

      Comment


        Originally posted by Jim Hearne View Post
        Is it just me or has anybody else only just had notification that this message was posted ?, i'm sure it wasn't there on the 27th when it says it was posted.

        I didn't think this forum was moderated, if you are registered the messages get posted straight away ?

        Jim
        I've had a few emails saying "Norv has just replied..." and when I come here to take a look, there's no evidence of his post! I didn't realize that there seems to be some bizarre delay/lag. Very weird...

        Dave.

        Comment


          Originally posted by Norv View Post
          Hi all
          My Cortex is still here looking for a good home, I don't think it helps that my posts seem to take up to a week to get past the moderator. By the time my posts get on the site you lot have moved on to the next page.
          I have no objections to it going to America or even further. I have a business address so it can be collected during the day by a courier.
          I have also found an a to d board that I don't think is quite finished and a few odd ic's (not 999 series) that can come with it.

          Norvin
          @Norvin, I would definitely be interested in the Cortex, then. I've been resurrecting the layouts for various Cortex boards, so the A/D board would be most interesting.

          @Stuart, if you are willing to do the pickup and ship it to me, I would greatly appreciate it--just let me know if you can do it.

          @Jim, I haven't seen Norvin's post prior to today either--or the previous one where he notes that it is fine with him if it comes to this side of the Pond. Definitely something strange going on with the board. . .
          Enter My Mind At Your Own Risk!

          Comment


            Originally posted by Norv View Post
            I don't Know if it is a junior member thing but I am registered and it always takes about a week for my posts to get on the forum but when they do go up the seem to be inserted back in date order for the time I sent them. but never mind please don't forget about my Cortex where is it going. I am starting to get my ear bent about it so need to get it sorted. I am posting this at 18;00 uk time on 2nd December.

            Norvin
            Hi Norv,

            For the record, I got email notification of your post @11:20 EST (16:20 GMT) today, December 5.

            Dave.

            Comment


              I've also just had notification of Norvins last post (#572), 3 days late.

              I'm posting this 18:44 on 5th.


              And it appears instantly, very strange.

              Jim
              Last edited by Jim Hearne; December 5, 2013, 10:54 AM.

              Comment


                Originally posted by Ksarul View Post
                @Norvin, I would definitely be interested in the Cortex, then. I've been resurrecting the layouts for various Cortex boards, so the A/D board would be most interesting.
                I've actually already tried scrounging the A/D board as well by PM though i'm not sure if Norvin has got it.
                But i'd be happy enough with some photos and buying a pcb from you once it's reverse engineered.

                Jim

                Comment


                  TI Microsystems Designers Handbook.

                  I found this in among the few data books that survived a clear out many years ago.

                  TI Microsystems Designers Handbook 2nd edition.pdf

                  It's a 100meg file but loads of interesting stuff in there.

                  If you just want to look at the E-Bus pages.

                  E-Bus pages

                  Jim

                  Comment


                    Porting ancient unix

                    Hello all,

                    Background

                    About a month ago I came across this thread and I have read it with much interest. I had never heard of the Cortex before reading this thread, but I do own a 99/4a. I powered it up about two years ago and was overjoyed to see it still work. Back in the day I had expanded it with 32K RAM on the 16 bit bus, and built an EPROM programmer and a 5.25" floppy disk driver for it, both from scratch. 30 years ago I wanted to put a mini unix on it, but that never materialised. That dream kept itching and was the driver for reviving the 99/4a. However, including an old telly it is too big a setup to be practical. Still, a 9900 plus 64K RAM should be enough to run Xinu and LSX unix. With a MMU and 256K it should be enough for Version 6 ("Lion's") unix. A 99105 or 99110 (having separate I/D spaces) should be enough for Version 7 and perhaps even BSD 2.11.

                    Via Dave's website I discovered the Cortex, Marinchip and the MDEX software. What an interesting read. By the way, Dave, your site lacks the general MDEX manual, but it is available on Jim Hearn's pages. Perhaps a forgotten item? Very impressed with the Cortex emulator by the way.

                    All in all, a Cortex with the disk hardware installed should be able to run LSX unix. This may sound unrealistic, but some Russian hackers have it running on a BK0010, a Russian home computer from the 1980's that uses a single chip PDP11 derivative as its CPU, and has 48K RAM. The software repo for it is over on Sourceforge.

                    I have no intention of building or owning a Cortex, but Stuart's breadboard projects look like a practical start to get my 30 year old project speeded up a bit.

                    Hardware

                    Stuart, thank you for these captivating designs and excellent web pages. You are getting quite a following: http://www.vaxman.de/projects/tms99xx/

                    I've just build the 9995 breadboard and it works like a charm. The CPU and UART came from G&C supermarket at eBay, which sells them for 7 and 3 euro respectively, free shipping via mail. The parts arrived after 19 and 28 days and turned out to be genuine. By mistake I ordered a 9902 instead of a 9902A, but it still works. I compared the datasheets and saw no obvious differences. Does anybody know the difference between the two?

                    I left out the MAX232 level shifter and hooked up the 9902 to a FTDI232 chip right away, using the Elektor/Circuit Cellar breakout board. http://www.elektor.com/magazines/201....1912360.lynkx
                    This way I can use the USB port as a power source and the system becomes a handy A5 sized USB peripheral. I also changed the LS04 to a LS14 (hex inverting schmitt-trigger) and used two inverters to make a (power-on) reset circuit. I have found that the LS138 is not actually needed: if one connects an inverted /MEMEN signal to the 9902 chip select it works equally well. Other adaptations are the use of an EEPROM and a 512K RAM chip. What results is a 6 chip fully functional computer (CPU, UART, RAM, ROM, LS14 and LS32).

                    Somebody suggested that the ROM should be bankable and that writes could always go to the RAM. I haven't tried this yet, but I think the following should work: if the RAM chip select is hooked up to /MEMEN it covers the full 64K. Its output enable becomes the OR of /DBIN and the inverted /ROM_CE. That latter becomes the OR of the original /ROM_CE and a new signal MAP. When MAP is low, the lower 32K are read from ROM, when MAP is high the ROM is disabled resulting in 64K of RAM.

                    Another modification I would like to try is adding the single stepping hardware. I think the Cortex circuit for this could work: decoding the external instructions with a LS138 and generating a /NMI signal with three flip-flops (two LS74's). The CKON/CKOFF instructions and the fourth flip-flop could be used to generate the MAP signal for above bank switching. This would take it from a 6 chip system to a 9 chip system, but still fitting on two strips of breadboard.

                    For disk I'm thinking about a microcontroller hooked up to an SD memory card, but that is for another day. Also for another day is building the 99105/99110 project.

                    Questions:
                    - any suggestions?
                    - connecting READY to /RESET should eliminate the automatic wait state. Has anybody done the recalculation work for the baud rate table?
                    - the only 99xxx I can find is a 50 euro part sold by 'timeline' on eBay, a UK source. Is that a known good source? Are there better alternatives?
                    - what is the best way to get software downloaded? 'Typing' a file from the terminal emulator to the breadboard seems a good way, but currently this overflows; I guess I need to hook up the hardware flow control signals.

                    Software

                    With convenient hardware now almost sorted, the next step is getting a good 9900 C compiler. This is what I lacked 30 years ago and I am still not there yet. These are the options I'm aware of:

                    - Clint Pulley's C99 for the 99/4a. This one is too limited for my purposes.

                    - Allan Beard's TI-C for the Geneve 9640. This one is based on Matthew Brandt's compiler for the 68K which is open source. A compiled version of TI-C for the 9640 is on whtech, but alas no sources. I'm trying to locate Allan Beard, but have not found him yet.

                    - Port the original Ritchie C compiler from PDP-11 to 9900. This is my current preferred route. With the 9900 similar to the PDP-11 in philosophy this should be feasible. I ported the version 6 compiler to modern C some 4 years ago (and the BK0010 project has done the BSD2.11 compiler). Already ported the assembler to 9900.

                    - Dave Pitt's GCC port. I couldn't get this to work out of the box and using GCC kinda kills the 'retro' attraction for me, as it could never run natively on a 16 bit machine.

                    Did the Cortex ever have a C compiler? Any other suggestions?

                    Thanks everybody for the wonderful preservation work!

                    Paul

                    Comment




                      scanning this at the moment, I'll upload it somewhere when it's finished
                      Attached Files

                      Comment


                        Wow, that will be great.

                        Many thanks,

                        Jim

                        Comment


                          Ebus system design book scanned, temporarily uploaded to https://www.dropbox.com/s/3dussnv2mr...stemDesign.pdf (11.5MByte), I can;t leave it there so if someone can copy it to somewhere permanent that would be good.

                          Comment


                            Hi Tony,
                            I have downloaded it, its now here: http://www.quantums.info/cortex/EbusSystemDesign.pdf

                            Sorry, i'm pushing my luck now, do you have the original scans in a higher resolution or with less jpg compression ?
                            I can't read all of the text on some of the pages with circuits, e.g page 148.

                            Many thanks again for taking the time to scan it for us.

                            Jim
                            Last edited by Jim Hearne; December 30, 2013, 03:03 PM.

                            Comment


                              Many thanks, Tony! I was beginning to think this document was lost in the mists of time!
                              Enter My Mind At Your Own Risk!

                              Comment


                                I've put the scan images at https://www.dropbox.com/s/htv987sqzz...signImages.zip (I wont leave anything there long term, I dont have much space). Can you recreate the complete pdf easily from images?

                                If there are any specific pages that need rescanning or at a higher resolution just let me know

                                Comment

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