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I can't make John's serial board with His Z-80 Board

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    If you read my post #29 you can configure P39 3-4 to use the first half of a 2764 as the monitor for $F000 to $FFFF.

    Incidentally, what RAM card are you using with the Z80 CPU card?



      Hi All;

      Thank You Dave for Your Prompt reply.. Yes, I read it, but, I was/am unsure if that is the setting for a 2732 as well..

      I have a Tanner 64K Memory board with F000 to FFFF excluded, so there is memory from 0000 to EFFF..

      THANK YOU Marty


        No it isn’t.

        You have to get the data sheet for the specific EPROM you are using and configure the Z80 CPU card jumpers to suit.

        There is such a wide variation in pinouts that any general statement is bound to be incorrect.



          Hi Dave;

          What I have is an AMD AM2732B..

          I'LL see what the Data sheets show for it..

          THANK YOU Marty


            Hi All;

            I tried to do as John stated in the Listing of the Master0 text, but instead of Master0 I used the Monitor text from Dave, but, when I tried to do it, it gave me an error of No Submit file..
            Where or how do I create the submit file for Dave's Monitor Text ??

            THANK YOU Marty


              Hi All;

              I got it to work !!!
              With Dave's Monitor Program, I thought the Hex2bin program wasn't working, but, once I did the conversion, I had to get out of that Directory, and come back to it and I had the Mon1.bin file, I loaded it into my Programmer and I programmed an AMD 2732.. And tried it and I got John's Monitor ready for me to respond to with a K and it displayed the appropiate Listing of files available..
              Which also means that my Serial Board is working, as well..

              THANK YOU Marty



                The original monitor looked like it needed more cards than you have to run. Bodging the monitor permits it to work on the hardware you have. There is still code in there for functions that require hardware you may not have. The speech stuff should still work (it uses the other serial port on the SCC). The disk controller part of the monitor may also be hardware specific?



                  Hi All;

                  Dave, Yes the next Board to drop in is the Floppy Drive Controller from John, Hopefully that will be an easy bringing up.. Compared to the Serial Board..
                  In awhile I will let You know what the situation is with it..
                  Ok, I have the Floppy Controller in, but I have forgotten how to access it, I will have to go to the web site for the floppy controller and take a peek..
                  But, it looks like it came up fine, I still have to get a floppy drive and a cable and a power supply to make things complete..

                  THANK YOU Marty
                  Last edited by Marty; April 17, 2020, 04:15 AM.


                    No problem.

                    By the way, how did your transistorised 8080 project go? Is it all finished now?



                      Hi All;

                      Dave, Thanks for asking, No it isn't done, I have either all or most of the boards soldered up, but, nothing, has been tested, He built another module that I could plug the various boards into to test them, but the software isn't there to do the tests..
                      And also, I have to carefully, look at each board, before applying power, looking for solder shorts, and that is a work in progress..

                      On the note from above, I looked at John's site for the ZFDC Floppy Controller, and He shows the menu for that board, but, it doesn't say how to get there from the main Z-80 menu..

                      THANK YOU Marty


                        Yes, don't damage the cards! Use a current-limiting power supply - my recommendation!

                        The ZFDC web page identifies that this test code is NOT part of the Z80 Monitor that you have already put onto the Z80 CPU board into EPROM - but a SEPARATE piece of diagnostic code (downloadable from the ZFDC web page) that is required to be burnt into a separate EPROM and swapped for the monitor on the Z80 CPU board.



                          Hi All;

                          Dave I have a couple of newer switchable set of power supplies in my Altair, I have had that for a Long tine..
                          The origional Power supply, is still there, but it is not connected..

                          I Looked and downloaded the files from John's zfdc site, and both of the ones I see would not fit even in a 2764, they do fit, (which I have already done when I built the zfdc Board), in a 27C256 type of eprom, which is what is on the zfdc board..

                          I don't see anything small enough to fit even in a 27C64 Eprom, for the Monitor in the Z-80..

                          THANK YOU Marty


                            You are right. My understanding is incorrect.

                            There is an EPROM fitted to the ZFDC board itself. If this doesn’t work, then the ZFDC card won’t either.

                            The diagnostic program is a CP/M program - so you have to get the ZFDC card working to boot CP/M to test the ZFDC...

                            Chickens and eggs come to mind here.



                              Hi All;

                              Dave, Thank You for Your response..

                              So, I still need to figure out, how to get to the ZFDC Command to display..

                              I know it can be done, Before, a year or two ago, when I last had things running, I had the system working, now (If I remember correctly I had 8" floppies), but it worked and I was able to Display the commands for the ZFDC Board..

                              I could use some input from someone who has worked with this System on bringing it up, piece by piece..

                              THANK YOU Marty


                                Everything you can do via the Z80 CPU monitor is defined in the text strings at the end of the monitor source code.

                                No more, no less...