Loading ...
Sorry, an error occurred while loading the content.

Re: [cosmacelf] Re: Memory Map of elf

Expand Messages
  • Richard
    see below ... From: Allen Bong To: Sent: Wednesday, December 10, 2003 1:04 AM Subject: [cosmacelf] Re: Memory
    Message 1 of 29 , Dec 10, 2003
    • 0 Attachment
      see below


      ----- Original Message -----
      From: "Allen Bong" <sfbong@...>
      To: <cosmacelf@yahoogroups.com>
      Sent: Wednesday, December 10, 2003 1:04 AM
      Subject: [cosmacelf] Re: Memory Map of elf


      > --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
      > > If The EHOPS program does not care where it is, and fine's it on
      > memory.
      > > You could put a double pole double throw switch in. Connected to
      > the chip
      > > select lines of the ram and Rom to switch these two around. Assum
      > following
      > > pin out of switch
      > > 1 2
      > > 3 4
      > > 5 6
      > > connect pin 1 to 6, 2 to 5, input ram to 3, input rom to 4,
      > output to
      > > ram 2 or 5, output to rom 1 or 6
      > >
      > > flipping switch would just reverse these to lines. You will need
      > make sure
      > > the connection you make leaves a pull up resistor connected to the
      > ram and
      > > rom, and that you put it in a place that they are both the same
      > polarity,
      > > 2716's chip select is active LOW. I don't Know what your ram's are.
      > >
      >
      > My ram are the similar one as used in the elf but it was of cmos
      > favour: - 5101
      >
      > > One note I Beleive you would have to be entering C0 08 00 not 30
      > 08. 30 08
      > > 00 would branch to address 0008.
      >
      >
      > Sorry, I forgot that there is a long branch for it.
      >
      >
      > >
      > > To Answer the other question about It Being Conventional.
      > >
      > > For Dedicatied Use It Is common to start it with rom at 0000. But
      > not for
      > > none dedicated use, most other programs start at 0000, with a rom
      > in the way
      > > they would not work. The soultion most used to solve this is zero
      > power
      > > rams or battery backup.
      > >
      > > I am sure there are other ways to switch this. But I would Have to
      > See how
      > > you decoded the 2716 and the Ram.
      >
      >
      > > I used almost the same scheme as described in Part 3 of the PE
      > construction
      > articles. Instead of using a 4 bit latch 4042 which I dont have any
      > in my
      > junk box, I used a 74HC174 6 bit latch together with a 74HC04 to get
      > the
      > inverted address /A10 for addressing the onboard 256 byte RAM. Out

      This is a problem the input of the 74HC04 needs to be moved to the /Y0
      output.
      of the decoder. (when the ROM is Address, A10 is still low so both the rom
      and ram is on.)

      The switch above would still be the way i would go, to keep it simple. when
      you get up to running the Tiny monitor combo, some one already has it set up
      to run from rom at 8000, and you will wont to reconfigure the way you are
      addressing. One word Of note: after you enter C0 08 00 a dozen or so times,
      you will get to a point you can do it in about 30 sec. adding the battery
      part of the artical would be a better use of your time. Then you put it in
      once and it will stay.

      if you use the switch, Then Put a 10k resistor from the input of the 74HC04
      to +5V, cut the line between the resistor and the decoder(if it is connected
      yet).

      Then put a 10k resistor from CE of the 2716 to +5V, and cut the line between
      the resistor and the decoder.

      you would than be reversing the /Y0 and /Y1 lines, the reason for the
      resistors it that when the switch is flipped, there is a time (ms) that
      nothing would be connected, and this could cause damage. You can then flip
      the switch with power on (processor not running).

      uses the decoder side as input on the switch.

      > of the
      > A8-A13 coming out of the '174, A11-A13 were used as inputs of a
      > 74HC138
      > 1-out-of-8-decoder. /Y0 output was left NC and /Y1 (0800-0FFF) was
      > connected to the /CS of the 2716. The /OE of 2716 was connected
      > to /MRD of
      > 1802. /Y2
      > was connected to the second 2716 and /Y3 to /Y7 were reserved for
      > future
      > use.
      >
      > The circuit was constructed on a 2"X4" perforated board and connected
      > to the
      > elf through a 26 pin ribbon cable. As I have plenty of 2716s
      > (savaged from
      > junked OKI teleprinter machines), there is no problem for me to
      > extend the
      > Eprom board when the program grows larger. I think I'd finally get
      > the Tiny
      > Basic and the IDIOT4 to run on my Elf after I get the serial interface
      > functioning.
      >
      > Regards
      >
      > Allen
      >
      >
      >
      > >
      > > ----- Original Message -----
      > > From: "Allen Bong" <sfbong@t...>
      > > To: <cosmacelf@yahoogroups.com>
      > > Sent: Tuesday, December 09, 2003 8:11 PM
      > > Subject: [cosmacelf] Memory Map of elf
      > >
      > >
      > > > Hi group,
      > > >
      > > > Was it a bit unconventional to start a 1802 with ram at address
      > 0000?
      > > Wouldn't it be better if ROM was placed at 0000? In this
      > > > way any monitor program would be able to start execution after
      > the cpu is
      > > reset.
      > > >
      > > > I am putting the EHOPS program in an 2716 eprom at 0800. Every
      > time I
      > > want to use the program I have to put 30 08 00 at
      > > > address 0000 using the toggle switches. Is there any way I can
      > add in
      > > some decoding logic controlled by a switch so I can swap
      > > > the address of the rom at 0800 with the ram at 0000 so I can have
      > the
      > > option of using the keypad entry or toggle switch entry if I
      > > > wish.......
      > > >
      > > > Thanks.
      > > >
      > > > Allen
      > > >
      > > >
      > > >
      > > >
      > > >
      > > >
      > > > ========================================================
      > > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
      > the
      > > Wiki/FAQ at http://1802.bitting.com/
      > > >
      > > > To unsubscribe from this group, send an email to:
      > > > cosmacelf-unsubscribe@yahoogroups.com
      > > >
      > > >
      > > >
      > > > Your use of Yahoo! Groups is subject to
      > http://docs.yahoo.com/info/terms/
      > > >
      > > >
      >
      >
      >
      > ========================================================
      > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view the
      Wiki/FAQ at http://1802.bitting.com/
      >
      > To unsubscribe from this group, send an email to:
      > cosmacelf-unsubscribe@yahoogroups.com
      >
      >
      >
      > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
      >
      >
    • Allen Bong
      ... wrote: Hi Josh, I have looked through your schematic and I found it very simple and well designed. Am I right understanding its working as below when the
      Message 2 of 29 , Dec 11, 2003
      • 0 Attachment
        --- In cosmacelf@yahoogroups.com, "joshbensadon" <joshbensadon@y...>
        wrote:

        Hi Josh,

        I have looked through your schematic and I found it very simple and
        well designed. Am I right understanding its working as below when
        the vip/elf switch is at the left?

        1. When the elf is switched on and the "RUN" is on, A15 should be at
        low.

        2. After completed executing LBRA 8003, A15 turns high and continue
        to run from 8003 normally as an eprom.

        3. OR A15 will become high after the F8 80 B3, F8 07 A3, D3 (sep r3)
        sequence at 8007.

        4. If the rom routine is accessing the ram as temporary variables,
        it should work.

        Allen


        > Hi Allen,
        >
        > > Yes, Your schematic on how you did it is very much appreciated.
        You
        > > may either email me direct to sfbong(at)tm(dot)net(dot)my or
        post it
        > > to the "files" section so any one who is interested may retrieve
        it.
        > >
        > > The schematics on how the VIP implement the ghosting would be
        nice
        > > too if you have it.
        >
        > It's the same idea, ghosting the EPROM is what VIP did.
        > I will post the file in my folder, members-JoshBensadon.
        >
        > It uses just 2 chips, 74HC00 and 74HC02, available in any junk
        box! :)
        >
        > Regards,
        > Josh
      • Allen Bong
        ... From: Richard To: Sent: Thursday, December 11, 2003 9:12 AM Subject: Re: [cosmacelf] Re: Memory Map of
        Message 3 of 29 , Dec 11, 2003
        • 0 Attachment
          ----- Original Message -----
          From: "Richard" <stateamuse@...>
          To: <cosmacelf@yahoogroups.com>
          Sent: Thursday, December 11, 2003 9:12 AM
          Subject: Re: [cosmacelf] Re: Memory Map of elf


          see below

          [..................text snipped...............】

          > > > I used almost the same scheme as described in Part 3 of the PE
          > > construction
          > > articles. Instead of using a 4 bit latch 4042 which I dont have any
          > > in my
          > > junk box, I used a 74HC174 6 bit latch together with a 74HC04 to get
          > > the
          > > inverted address /A10 for addressing the onboard 256 byte RAM. Out
          >

          > This is a problem the input of the 74HC04 needs to be moved to the /Y0
          > output.
          > of the decoder. (when the ROM is Address, A10 is still low so both the
          rom
          > and ram is on.)

          Oop, I must have over-looked this one. But the EHOPS still works as it is
          less than 256 bytes long.
          I think problems will surface when executing programs starting from
          0c00-0fff when A10 turns high.

          .................................................snipped....................
          ..........
        • Richard
          You must have something else connected, Is Anything connected to the decoder enable lines (pins 4,5,6). If The RAM is Address At 0 then there would be a
          Message 4 of 29 , Dec 11, 2003
          • 0 Attachment
            You must have something else connected, Is Anything connected to the
            decoder enable lines (pins 4,5,6).
            If The RAM is Address At 0 then there would be a problem with with
            addressing 0800. The A10 line is low in both cases.



            ----- Original Message -----
            From: "Allen Bong" <sfbong@...>
            To: <cosmacelf@yahoogroups.com>
            Sent: Thursday, December 11, 2003 9:10 AM
            Subject: Re: [cosmacelf] Re: Memory Map of elf


            >
            > ----- Original Message -----
            > From: "Richard" <stateamuse@...>
            > To: <cosmacelf@yahoogroups.com>
            > Sent: Thursday, December 11, 2003 9:12 AM
            > Subject: Re: [cosmacelf] Re: Memory Map of elf
            >
            >
            > see below
            >
            > [..................text snipped...............】
            >
            > > > > I used almost the same scheme as described in Part 3 of the PE
            > > > construction
            > > > articles. Instead of using a 4 bit latch 4042 which I dont have any
            > > > in my
            > > > junk box, I used a 74HC174 6 bit latch together with a 74HC04 to get
            > > > the
            > > > inverted address /A10 for addressing the onboard 256 byte RAM. Out
            > >
            >
            > > This is a problem the input of the 74HC04 needs to be moved to the /Y0
            > > output.
            > > of the decoder. (when the ROM is Address, A10 is still low so both the
            > rom
            > > and ram is on.)
            >
            > Oop, I must have over-looked this one. But the EHOPS still works as it is
            > less than 256 bytes long.
            > I think problems will surface when executing programs starting from
            > 0c00-0fff when A10 turns high.
            >
            >
            .................................................snipped....................
            > ..........
            >
            >
            >
            >
            > ========================================================
            > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view the
            Wiki/FAQ at http://1802.bitting.com/
            >
            > To unsubscribe from this group, send an email to:
            > cosmacelf-unsubscribe@yahoogroups.com
            >
            >
            >
            > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
            >
            >
          • Allen Bong
            ... No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram was enabled using the /A10 using HC04. So when my program executes from 0800 to 08FF,
            Message 5 of 29 , Dec 11, 2003
            • 0 Attachment
              --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:

              No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram was
              enabled using the /A10 using HC04. So when my program executes from
              0800 to 08FF, /A10 was high all the time: ie. (0000,1000,0000,0000 to
              0000,1000,1111,1111).

              Allen



              > You must have something else connected, Is Anything connected to
              the
              > decoder enable lines (pins 4,5,6).
              > If The RAM is Address At 0 then there would be a problem with with
              > addressing 0800. The A10 line is low in both cases.
              >
              >
              >
              > ----- Original Message -----
              > From: "Allen Bong" <sfbong@t...>
              > To: <cosmacelf@yahoogroups.com>
              > Sent: Thursday, December 11, 2003 9:10 AM
              > Subject: Re: [cosmacelf] Re: Memory Map of elf
              >
              >
              > >
              > > ----- Original Message -----
              > > From: "Richard" <stateamuse@c...>
              > > To: <cosmacelf@yahoogroups.com>
              > > Sent: Thursday, December 11, 2003 9:12 AM
              > > Subject: Re: [cosmacelf] Re: Memory Map of elf
              > >
              > >
              > > see below
              > >
              > > [..................text snipped...............ã€`
              > >
              > > > > > I used almost the same scheme as described in Part 3 of the
              PE
              > > > > construction
              > > > > articles. Instead of using a 4 bit latch 4042 which I dont
              have any
              > > > > in my
              > > > > junk box, I used a 74HC174 6 bit latch together with a 74HC04
              to get
              > > > > the
              > > > > inverted address /A10 for addressing the onboard 256 byte
              RAM. Out
              > > >
              > >
              > > > This is a problem the input of the 74HC04 needs to be moved to
              the /Y0
              > > > output.
              > > > of the decoder. (when the ROM is Address, A10 is still low so
              both the
              > > rom
              > > > and ram is on.)
              > >
              > > Oop, I must have over-looked this one. But the EHOPS still works
              as it is
              > > less than 256 bytes long.
              > > I think problems will surface when executing programs starting
              from
              > > 0c00-0fff when A10 turns high.
              > >
              > >
              > .................................................snipped............
              ........
              > > ..........
              > >
              > >
              > >
              > >
              > > ========================================================
              > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
              the
              > Wiki/FAQ at http://1802.bitting.com/
              > >
              > > To unsubscribe from this group, send an email to:
              > > cosmacelf-unsubscribe@yahoogroups.com
              > >
              > >
              > >
              > > Your use of Yahoo! Groups is subject to
              http://docs.yahoo.com/info/terms/
              > >
              > >
            • sfbong@tm.net.my
              Hi Richard, I myself was also quite confused how the ram works when the 2716 was enabled. Anyway the card is still with me and I am going to trace the
              Message 6 of 29 , Dec 11, 2003
              • 0 Attachment
                Hi Richard,

                I myself was also quite confused how the ram works when the 2716 was enabled. Anyway the card is still with me and I am going to trace the schematic again to-night just to solve the mystery. Sorry for any misleading informations that I gave!

                Allen.


                ----- Original Message -----
                From: Allen Bong <sfbong@...>
                Date: Friday, December 12, 2003 11:11 am
                Subject: [cosmacelf] Re: Memory Map of elf

                > --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
                >
                > No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram
                > was
                > enabled using the /A10 using HC04. So when my program executes
                > from
                > 0800 to 08FF, /A10 was high all the time: ie. (0000,1000,0000,0000
                > to
                > 0000,1000,1111,1111).
                >
                > Allen
                >
                >
                >
                > > You must have something else connected, Is Anything connected
                > to
                > the
                > > decoder enable lines (pins 4,5,6).
                > > If The RAM is Address At 0 then there would be a problem with with
                > > addressing 0800. The A10 line is low in both cases.
                > >
                > >
                > >
                > > ----- Original Message -----
                > > From: "Allen Bong" <sfbong@t...>
                > > To: <cosmacelf@yahoogroups.com>
                > > Sent: Thursday, December 11, 2003 9:10 AM
                > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                > >
                > >
                > > >
                > > > ----- Original Message -----
                > > > From: "Richard" <stateamuse@c...>
                > > > To: <cosmacelf@yahoogroups.com>
                > > > Sent: Thursday, December 11, 2003 9:12 AM
                > > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                > > >
                > > >
                > > > see below
                > > >
                > > > [..................text snipped...............ã?`
                > > >
                > > > > > > I used almost the same scheme as described in Part 3 of
                > the
                > PE
                > > > > > construction
                > > > > > articles. Instead of using a 4 bit latch 4042 which I
                > dont
                > have any
                > > > > > in my
                > > > > > junk box, I used a 74HC174 6 bit latch together with a
                > 74HC04
                > to get
                > > > > > the
                > > > > > inverted address /A10 for addressing the onboard 256 byte
                > RAM. Out
                > > > >
                > > >
                > > > > This is a problem the input of the 74HC04 needs to be moved
                > to
                > the /Y0
                > > > > output.
                > > > > of the decoder. (when the ROM is Address, A10 is still low
                > so
                > both the
                > > > rom
                > > > > and ram is on.)
                > > >
                > > > Oop, I must have over-looked this one. But the EHOPS still
                > works
                > as it is
                > > > less than 256 bytes long.
                > > > I think problems will surface when executing programs starting
                > from
                > > > 0c00-0fff when A10 turns high.
                > > >
                > > >
                > > .................................................snipped............
                > ........
                > > > ..........
                > > >
                > > >
                > > >
                > > >
                > > > ========================================================
                > > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or
                > view
                > the
                > > Wiki/FAQ at http://1802.bitting.com/
                > > >
                > > > To unsubscribe from this group, send an email to:
                > > > cosmacelf-unsubscribe@yahoogroups.com
                > > >
                > > >
                > > >
                > > > Your use of Yahoo! Groups is subject to
                > http://docs.yahoo.com/info/terms/
                > > >
                > > >
                >
                >
                > ------------------------ Yahoo! Groups Sponsor --------------------
                > -~-->
                > Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark
                > Printer at MyInks.com. Free s/h on orders $50 or more to the US &
                > Canada.http://www.c1tracking.com/l.asp?cid=5511
                > http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/S_NqlB/TM
                > -------------------------------------------------------------------
                > --~->
                >
                > ========================================================
                > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
                > the Wiki/FAQ at http://1802.bitting.com/
                >
                > To unsubscribe from this group, send an email to:
                > cosmacelf-unsubscribe@yahoogroups.com
                >
                >
                >
                > Your use of Yahoo! Groups is subject to
                > http://docs.yahoo.com/info/terms/
                >
                >
                >
              • Richard
                see below ... From: Allen Bong To: Sent: Thursday, December 11, 2003 10:11 PM Subject: [cosmacelf] Re: Memory
                Message 7 of 29 , Dec 11, 2003
                • 0 Attachment
                  see below

                  ----- Original Message -----
                  From: "Allen Bong" <sfbong@...>
                  To: <cosmacelf@yahoogroups.com>
                  Sent: Thursday, December 11, 2003 10:11 PM
                  Subject: [cosmacelf] Re: Memory Map of elf


                  --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:

                  No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram was
                  enabled using the /A10 using HC04. So when my program executes from
                  0800 to 08FF, /A10 was high all the time: ie. (0000,1000,0000,0000 to
                  0000,1000,1111,1111).

                  Yes This Is True. Note: A10 is LOW and /A10 Would still be High
                  the only reason the inverter was used is because the 5101 RAM is active High
                  instead of Low like the ROM. So anytime You use your ROM The RAM is active.
                  The ROM must be winning when there is a read. The Fact that the Rom is not
                  active when Ram is used is what is making it work, But I Don't Know How Long
                  The Ram chips Can take the punishment.


                  Allen



                  > You must have something else connected, Is Anything connected to
                  the
                  > decoder enable lines (pins 4,5,6).
                  > If The RAM is Address At 0 then there would be a problem with with
                  > addressing 0800. The A10 line is low in both cases.
                  >
                  >
                  >
                  > ----- Original Message -----
                  > From: "Allen Bong" <sfbong@t...>
                  > To: <cosmacelf@yahoogroups.com>
                  > Sent: Thursday, December 11, 2003 9:10 AM
                  > Subject: Re: [cosmacelf] Re: Memory Map of elf
                  >
                  >
                  > >
                  > > ----- Original Message -----
                  > > From: "Richard" <stateamuse@c...>
                  > > To: <cosmacelf@yahoogroups.com>
                  > > Sent: Thursday, December 11, 2003 9:12 AM
                  > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                  > >
                  > >
                  > > see below
                  > >
                  > > [..................text snipped...............ã?`
                  > >
                  > > > > > I used almost the same scheme as described in Part 3 of the
                  PE
                  > > > > construction
                  > > > > articles. Instead of using a 4 bit latch 4042 which I dont
                  have any
                  > > > > in my
                  > > > > junk box, I used a 74HC174 6 bit latch together with a 74HC04
                  to get
                  > > > > the
                  > > > > inverted address /A10 for addressing the onboard 256 byte
                  RAM. Out
                  > > >
                  > >
                  > > > This is a problem the input of the 74HC04 needs to be moved to
                  the /Y0
                  > > > output.
                  > > > of the decoder. (when the ROM is Address, A10 is still low so
                  both the
                  > > rom
                  > > > and ram is on.)
                  > >
                  > > Oop, I must have over-looked this one. But the EHOPS still works
                  as it is
                  > > less than 256 bytes long.
                  > > I think problems will surface when executing programs starting
                  from
                  > > 0c00-0fff when A10 turns high.
                  > >
                  > >
                  > .................................................snipped............
                  ........
                  > > ..........
                  > >
                  > >
                  > >
                  > >
                  > > ========================================================
                  > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
                  the
                  > Wiki/FAQ at http://1802.bitting.com/
                  > >
                  > > To unsubscribe from this group, send an email to:
                  > > cosmacelf-unsubscribe@yahoogroups.com
                  > >
                  > >
                  > >
                  > > Your use of Yahoo! Groups is subject to
                  http://docs.yahoo.com/info/terms/
                  > >
                  > >



                  ========================================================
                  Visit the COSMAC ELF website at http://www.cosmacelf.com, or view the
                  Wiki/FAQ at http://1802.bitting.com/

                  To unsubscribe from this group, send an email to:
                  cosmacelf-unsubscribe@yahoogroups.com



                  Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                • joshbensadon
                  Allen, ... Yes, that is right. ... Well, A15 turns high for some reason when the C8 instruction is loaded that is why A15 is AND d with MRead, so the flip/flop
                  Message 8 of 29 , Dec 12, 2003
                  • 0 Attachment
                    Allen,


                    > 1. When the elf is switched on and the "RUN" is on, A15 should be at
                    > low.

                    Yes, that is right.

                    > 2. After completed executing LBRA 8003, A15 turns high and continue
                    > to run from 8003 normally as an eprom.
                    > 3. OR A15 will become high after the F8 80 B3, F8 07 A3, D3 (sep r3)
                    > sequence at 8007.

                    Well, A15 turns high for some reason when the C8 instruction is loaded
                    that is why A15 is AND'd with MRead, so the flip/flop only sets once
                    an actual Memory Read where A15 is high. This will occur when the
                    1802 does the next instruction fetch after the LBRA 8003 or the SEP R3.
                    Once it does this, the EPROM ghosting is over and the RAM is accessible
                    @ addresses 0000-7FFF.

                    > 4. If the rom routine is accessing the ram as temporary variables,
                    > it should work.

                    Yes.

                    Josh
                  • Allen Bong
                    ... Richard, I must apologize for the wrong informations given on my earlier posts. After tracing the circuit board, I found that the inverter was actually
                    Message 9 of 29 , Dec 12, 2003
                    • 0 Attachment
                      --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
                      > see below
                      >
                      > ----- Original Message -----
                      > From: "Allen Bong" <sfbong@t...>
                      > To: <cosmacelf@yahoogroups.com>
                      > Sent: Thursday, December 11, 2003 10:11 PM
                      > Subject: [cosmacelf] Re: Memory Map of elf
                      >
                      >
                      > --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
                      >

                      Richard,

                      I must apologize for the wrong informations given on my earlier posts.

                      After tracing the circuit board, I found that the inverter was
                      actually inverting the TPA signal for the HC174 clock. The strobe of
                      the 4042 was programmable but the HC174 only accepts a low to high in
                      order to latch in A8-A15 on Q output (if that is what I understand
                      from the datasheet).

                      The RAM was chip selected using the A11 signal (not inverted) on pin
                      19 of the 5101. So it is still wrong if a second 2716 is added. I
                      have corrected the mistakes on my EPROM board and I am going to put
                      in Josh's circuit tonight. I just have to change the HC04 to HC00
                      and add another HC02. There was one extra gate on the HC00 which can
                      be used as an inverter for the HC174.

                      There are 2 extra pins on my 26 pin IDC connector for bringing in
                      the "RUN" signal. So I just have to add a change-over toggle switch
                      on the eprom card and reassemble the EHOPS program with the extra
                      instruction at 0800 and I think it should work.

                      I would probably need some help from our group on how to put in a
                      6116 ram with battery backup (or the Dallas RAM) to take over the
                      5101 when I am ready.

                      Allen

                      > No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram
                      was
                      > enabled using the /A10 using HC04. So when my program executes from
                      > 0800 to 08FF, /A10 was high all the time: ie. (0000,1000,0000,0000
                      to
                      > 0000,1000,1111,1111).
                      >
                      > Yes This Is True. Note: A10 is LOW and /A10 Would still be High
                      > the only reason the inverter was used is because the 5101 RAM is
                      active High
                      > instead of Low like the ROM. So anytime You use your ROM The RAM
                      is active.
                      > The ROM must be winning when there is a read. The Fact that the
                      Rom is not
                      > active when Ram is used is what is making it work, But I Don't Know
                      How Long
                      > The Ram chips Can take the punishment.
                      >
                      >
                      > Allen
                      >
                      >
                      >
                      > > You must have something else connected, Is Anything connected to
                      > the
                      > > decoder enable lines (pins 4,5,6).
                      > > If The RAM is Address At 0 then there would be a problem with with
                      > > addressing 0800. The A10 line is low in both cases.
                      > >
                      > >
                      > >
                      > > ----- Original Message -----
                      > > From: "Allen Bong" <sfbong@t...>
                      > > To: <cosmacelf@yahoogroups.com>
                      > > Sent: Thursday, December 11, 2003 9:10 AM
                      > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                      > >
                      > >
                      > > >
                      > > > ----- Original Message -----
                      > > > From: "Richard" <stateamuse@c...>
                      > > > To: <cosmacelf@yahoogroups.com>
                      > > > Sent: Thursday, December 11, 2003 9:12 AM
                      > > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                      > > >
                      > > >
                      > > > see below
                      > > >
                      > > > [..................text snipped...............ã?`
                      > > >
                      > > > > > > I used almost the same scheme as described in Part 3 of
                      the
                      > PE
                      > > > > > construction
                      > > > > > articles. Instead of using a 4 bit latch 4042 which I dont
                      > have any
                      > > > > > in my
                      > > > > > junk box, I used a 74HC174 6 bit latch together with a
                      74HC04
                      > to get
                      > > > > > the
                      > > > > > inverted address /A10 for addressing the onboard 256 byte
                      > RAM. Out
                      > > > >
                      > > >
                      > > > > This is a problem the input of the 74HC04 needs to be moved to
                      > the /Y0
                      > > > > output.
                      > > > > of the decoder. (when the ROM is Address, A10 is still low so
                      > both the
                      > > > rom
                      > > > > and ram is on.)
                      > > >
                      > > > Oop, I must have over-looked this one. But the EHOPS still
                      works
                      > as it is
                      > > > less than 256 bytes long.
                      > > > I think problems will surface when executing programs starting
                      > from
                      > > > 0c00-0fff when A10 turns high.
                      > > >
                      > > >
                      >
                      > .................................................snipped............
                      > ........
                      > > > ..........
                      > > >
                      > > >
                      > > >
                      > > >
                      > > > ========================================================
                      > > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or
                      view
                      > the
                      > > Wiki/FAQ at http://1802.bitting.com/
                      > > >
                      > > > To unsubscribe from this group, send an email to:
                      > > > cosmacelf-unsubscribe@yahoogroups.com
                      > > >
                      > > >
                      > > >
                      > > > Your use of Yahoo! Groups is subject to
                      > http://docs.yahoo.com/info/terms/
                      > > >
                      > > >
                      >
                      >
                      >
                      > ========================================================
                      > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
                      the
                      > Wiki/FAQ at http://1802.bitting.com/
                      >
                      > To unsubscribe from this group, send an email to:
                      > cosmacelf-unsubscribe@yahoogroups.com
                      >
                      >
                      >
                      > Your use of Yahoo! Groups is subject to
                      http://docs.yahoo.com/info/terms/
                    • Richard
                      what I was saying about the dallas chip was you could put this in your eprom board, and only change the one pin. and use /Y0 select signal. As for the 6116
                      Message 10 of 29 , Dec 12, 2003
                      • 0 Attachment
                        what I was saying about the dallas chip was you could put this in your eprom
                        board, and only change the one pin. and use /Y0 select signal. As for the
                        6116 battery you need 2- diodes and a 3.6 volt Litium battery. or 1-diode
                        a 270ohm resistor and a 3.6V rechargeable nickel cadium battery, But the
                        Litium will works better. They don't break down and leak all over your
                        circuit board.


                        ----- Original Message -----
                        From: "Allen Bong" <sfbong@...>
                        To: <cosmacelf@yahoogroups.com>
                        Sent: Friday, December 12, 2003 8:29 PM
                        Subject: [cosmacelf] Re: Memory Map of elf


                        --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
                        > see below
                        >
                        > ----- Original Message -----
                        > From: "Allen Bong" <sfbong@t...>
                        > To: <cosmacelf@yahoogroups.com>
                        > Sent: Thursday, December 11, 2003 10:11 PM
                        > Subject: [cosmacelf] Re: Memory Map of elf
                        >
                        >
                        > --- In cosmacelf@yahoogroups.com, "Richard" <stateamuse@c...> wrote:
                        >

                        Richard,

                        I must apologize for the wrong informations given on my earlier posts.

                        After tracing the circuit board, I found that the inverter was
                        actually inverting the TPA signal for the HC174 clock. The strobe of
                        the 4042 was programmable but the HC174 only accepts a low to high in
                        order to latch in A8-A15 on Q output (if that is what I understand
                        from the datasheet).

                        The RAM was chip selected using the A11 signal (not inverted) on pin
                        19 of the 5101. So it is still wrong if a second 2716 is added. I
                        have corrected the mistakes on my EPROM board and I am going to put
                        in Josh's circuit tonight. I just have to change the HC04 to HC00
                        and add another HC02. There was one extra gate on the HC00 which can
                        be used as an inverter for the HC174.

                        There are 2 extra pins on my 26 pin IDC connector for bringing in
                        the "RUN" signal. So I just have to add a change-over toggle switch
                        on the eprom card and reassemble the EHOPS program with the extra
                        instruction at 0800 and I think it should work.

                        I would probably need some help from our group on how to put in a
                        6116 ram with battery backup (or the Dallas RAM) to take over the
                        5101 when I am ready.

                        Allen

                        > No, pins 4&5 are gounded and pin 6 was connected to Vcc. The ram
                        was
                        > enabled using the /A10 using HC04. So when my program executes from
                        > 0800 to 08FF, /A10 was high all the time: ie. (0000,1000,0000,0000
                        to
                        > 0000,1000,1111,1111).
                        >
                        > Yes This Is True. Note: A10 is LOW and /A10 Would still be High
                        > the only reason the inverter was used is because the 5101 RAM is
                        active High
                        > instead of Low like the ROM. So anytime You use your ROM The RAM
                        is active.
                        > The ROM must be winning when there is a read. The Fact that the
                        Rom is not
                        > active when Ram is used is what is making it work, But I Don't Know
                        How Long
                        > The Ram chips Can take the punishment.
                        >
                        >
                        > Allen
                        >
                        >
                        >
                        > > You must have something else connected, Is Anything connected to
                        > the
                        > > decoder enable lines (pins 4,5,6).
                        > > If The RAM is Address At 0 then there would be a problem with with
                        > > addressing 0800. The A10 line is low in both cases.
                        > >
                        > >
                        > >
                        > > ----- Original Message -----
                        > > From: "Allen Bong" <sfbong@t...>
                        > > To: <cosmacelf@yahoogroups.com>
                        > > Sent: Thursday, December 11, 2003 9:10 AM
                        > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                        > >
                        > >
                        > > >
                        > > > ----- Original Message -----
                        > > > From: "Richard" <stateamuse@c...>
                        > > > To: <cosmacelf@yahoogroups.com>
                        > > > Sent: Thursday, December 11, 2003 9:12 AM
                        > > > Subject: Re: [cosmacelf] Re: Memory Map of elf
                        > > >
                        > > >
                        > > > see below
                        > > >
                        > > > [..................text snipped...............ã?`
                        > > >
                        > > > > > > I used almost the same scheme as described in Part 3 of
                        the
                        > PE
                        > > > > > construction
                        > > > > > articles. Instead of using a 4 bit latch 4042 which I dont
                        > have any
                        > > > > > in my
                        > > > > > junk box, I used a 74HC174 6 bit latch together with a
                        74HC04
                        > to get
                        > > > > > the
                        > > > > > inverted address /A10 for addressing the onboard 256 byte
                        > RAM. Out
                        > > > >
                        > > >
                        > > > > This is a problem the input of the 74HC04 needs to be moved to
                        > the /Y0
                        > > > > output.
                        > > > > of the decoder. (when the ROM is Address, A10 is still low so
                        > both the
                        > > > rom
                        > > > > and ram is on.)
                        > > >
                        > > > Oop, I must have over-looked this one. But the EHOPS still
                        works
                        > as it is
                        > > > less than 256 bytes long.
                        > > > I think problems will surface when executing programs starting
                        > from
                        > > > 0c00-0fff when A10 turns high.
                        > > >
                        > > >
                        >
                        > .................................................snipped............
                        > ........
                        > > > ..........
                        > > >
                        > > >
                        > > >
                        > > >
                        > > > ========================================================
                        > > > Visit the COSMAC ELF website at http://www.cosmacelf.com, or
                        view
                        > the
                        > > Wiki/FAQ at http://1802.bitting.com/
                        > > >
                        > > > To unsubscribe from this group, send an email to:
                        > > > cosmacelf-unsubscribe@yahoogroups.com
                        > > >
                        > > >
                        > > >
                        > > > Your use of Yahoo! Groups is subject to
                        > http://docs.yahoo.com/info/terms/
                        > > >
                        > > >
                        >
                        >
                        >
                        > ========================================================
                        > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
                        the
                        > Wiki/FAQ at http://1802.bitting.com/
                        >
                        > To unsubscribe from this group, send an email to:
                        > cosmacelf-unsubscribe@yahoogroups.com
                        >
                        >
                        >
                        > Your use of Yahoo! Groups is subject to
                        http://docs.yahoo.com/info/terms/



                        ========================================================
                        Visit the COSMAC ELF website at http://www.cosmacelf.com, or view the
                        Wiki/FAQ at http://1802.bitting.com/

                        To unsubscribe from this group, send an email to:
                        cosmacelf-unsubscribe@yahoogroups.com



                        Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                      • Allen Bong
                        ... 0000? ... the cpu ... machine ... The ... a ... approach. ... CPU ... Hi Dave, I have printed and studied the 3 schematics of the ACE CPU on your cosmac
                        Message 11 of 29 , Dec 13, 2003
                        • 0 Attachment
                          --- In cosmacelf@yahoogroups.com, Dave Ruske <dave@r...> wrote:
                          > On Tuesday, December 9, 2003, at 07:11 PM, Allen Bong wrote:
                          > > Was it a bit unconventional to start a 1802 with ram at address
                          0000?
                          > > Wouldn't it be better if ROM was placed at 0000? In this
                          > > way any monitor program would be able to start execution after
                          the cpu
                          > > is reset.
                          >
                          > The ACE CPU card took the approach of hijacking the first 24
                          machine
                          > cycles, forcing a C0 xx 00 onto the bus to simulate a long branch.
                          The
                          > "xx" was set via DIP switches on the card, allowing it to jump to
                          a
                          > monitor ROM on reset. I thought it was kind of an interesting
                          approach.
                          >
                          > I've been doing some scans recently, I'll try to get to the ACE
                          CPU
                          > card soon.
                          >
                          > Dave

                          Hi Dave,

                          I have printed and studied the 3 schematics of the ACE CPU on your
                          cosmac elf website. I can understand how the instruction C0 pp 00
                          was generated using the 4556. But I cant understand how the RAM
                          (6116 I guess) data was tri-stated during that 24 clock cycles.


                          Allen
                        • Dave Ruske
                          ... I don t have the time to dig into it at the moment, but one thing to watch for is that the RAM at 0000 wasn t necessarily on the CPU card. My system has
                          Message 12 of 29 , Dec 13, 2003
                          • 0 Attachment
                            On Saturday, December 13, 2003, at 09:46 AM, Allen Bong wrote:
                            > I have printed and studied the 3 schematics of the ACE CPU on your
                            > cosmac elf website. I can understand how the instruction C0 pp 00
                            > was generated using the 4556. But I cant understand how the RAM
                            > (6116 I guess) data was tri-stated during that 24 clock cycles.

                            I don't have the time to dig into it at the moment, but one thing to
                            watch for is that the RAM at 0000 wasn't necessarily on the CPU card.
                            My system has some EPROM and 2K of RAM on that card, but the bulk of
                            the RAM (including page 0) is on a separate 64K dynamic RAM card. I
                            don't recall whether the data from memory was tri-stated on the CPU
                            card itself or via a signal on the bus.

                            Thanks for the reminder... I'd completely forgotten that I'd already
                            scanned in and posted those schematics!

                            Dave
                          • Allen Bong
                            ... already ... I am just lucky though. I search through all the message headers in this group and found the discussion on the ACE Bus at follows
                            Message 13 of 29 , Dec 14, 2003
                            • 0 Attachment
                              --- In cosmacelf@yahoogroups.com, Dave Ruske <dave@r...> wrote:

                              > On Saturday, December 13, 2003, at 09:46 AM, Allen Bong wrote:
                              >
                              > Thanks for the reminder... I'd completely forgotten that I'd
                              already
                              > scanned in and posted those schematics!

                              I am just lucky though. I search through all the message headers in
                              this group and found the discussion on the ACE Bus at follows

                              http://groups.yahoo.com/group/cosmacelf/message/1093

                              Do you think someone would be interested in an article in PE on an
                              article call "An 1802 based EPROM programmer"? the programmer only
                              programs 2708 eprom. If you want, I can photo-copy/scan the article
                              for your website. It is only 3 pages long in the June-81 PE.

                              Allen
                            • Stewart
                              ... Hi Allen, I for one would love to see it. Sounds like an interesting wire wrap project! And the white-gold 2708 eproms turn up on eBay regularly. They
                              Message 14 of 29 , Dec 15, 2003
                              • 0 Attachment
                                --- In cosmacelf@yahoogroups.com, "Allen Bong" <sfbong@t...> wrote:
                                > Do you think someone would be interested in an article in PE on an
                                > article call "An 1802 based EPROM programmer"? the programmer only
                                > programs 2708 eprom. If you want, I can photo-copy/scan the article
                                > for your website. It is only 3 pages long in the June-81 PE.

                                Hi Allen, I for one would love to see it. Sounds like an interesting
                                wire wrap project! And the white-gold 2708 eproms turn up on eBay
                                regularly. They are a pain with their different voltages but are
                                certainly typical of that period in the circuits of the mid Seventies.
                                Can you save the article as a PDF after scanning it?

                                Stewart
                              • sfbong@tm.net.my
                                ... From: Stewart Date: Tuesday, December 16, 2003 9:24 am Subject: [cosmacelf] 1802 eprom programmer ... Hi Stewart, I will try my best
                                Message 15 of 29 , Dec 15, 2003
                                • 0 Attachment
                                  ----- Original Message -----
                                  From: Stewart <stew_m_3@...>
                                  Date: Tuesday, December 16, 2003 9:24 am
                                  Subject: [cosmacelf] 1802 eprom programmer

                                  > --- In cosmacelf@yahoogroups.com, "Allen Bong" <sfbong@t...> wrote:
                                  > > Do you think someone would be interested in an article in PE on
                                  > an
                                  > > article call "An 1802 based EPROM programmer"? the programmer
                                  > only
                                  > > programs 2708 eprom. If you want, I can photo-copy/scan the
                                  > article
                                  > > for your website. It is only 3 pages long in the June-81 PE.
                                  >
                                  > Hi Allen, I for one would love to see it. Sounds like an interesting
                                  > wire wrap project! And the white-gold 2708 eproms turn up on eBay
                                  > regularly. They are a pain with their different voltages but are
                                  > certainly typical of that period in the circuits of the mid Seventies.
                                  > Can you save the article as a PDF after scanning it?
                                  >
                                  > Stewart

                                  Hi Stewart,

                                  I will try my best to scan it first. I have the Adobe PDF programs in CD but dont know which one and how to use it. But I guess I can learn. I will post it to the file section when it is ready.

                                  Allen

                                  >
                                  >
                                  > ------------------------ Yahoo! Groups Sponsor --------------------
                                  > -~-->
                                  > Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark
                                  > Printer at MyInks.com. Free s/h on orders $50 or more to the US &
                                  > Canada.http://www.c1tracking.com/l.asp?cid=5511
                                  > http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/S_NqlB/TM
                                  > -------------------------------------------------------------------
                                  > --~->
                                  >
                                  > ========================================================
                                  > Visit the COSMAC ELF website at http://www.cosmacelf.com, or view
                                  > the Wiki/FAQ at http://1802.bitting.com/
                                  >
                                  > To unsubscribe from this group, send an email to:
                                  > cosmacelf-unsubscribe@yahoogroups.com
                                  >
                                  >
                                  >
                                  > Your use of Yahoo! Groups is subject to
                                  > http://docs.yahoo.com/info/terms/
                                  >
                                  >
                                  >
                                • Peter de Vroomen
                                  Hi, I was browsing some old magazines yesterday (some other than I was speaking about a few weeks ago), and to my surprise there was a Microcomputing
                                  Message 16 of 29 , Jun 4, 2004
                                  • 0 Attachment
                                    Hi,

                                    I was browsing some old magazines yesterday (some other than I was speaking
                                    about a few weeks ago), and to my surprise there was a 'Microcomputing'
                                    (formerly known as Kilobaud) issue with a 2716 eprom programmer based on an
                                    1802 processor.

                                    I'll scan it if there's an interest.

                                    PeterV
                                  • Michael Fogus
                                    ... I would personally love to see a scan! -m # # http://www.minotaurcomputing.com #
                                    Message 17 of 29 , Jun 4, 2004
                                    • 0 Attachment
                                      > I'll scan it if there's an interest.

                                      I would personally love to see a scan!
                                      -m


                                      #
                                      # http://www.minotaurcomputing.com
                                      #
                                    • Peter de Vroomen
                                      ... Ok, the trouble was that my scanner s powersupply died, but I hacked another powersupply to work with it. So I managed to scan the pages :) (there are 2).
                                      Message 18 of 29 , Jun 6, 2004
                                      • 0 Attachment
                                        > > I'll scan it if there's an interest.
                                        >
                                        > I would personally love to see a scan!

                                        Ok, the trouble was that my scanner's powersupply died, but I hacked another
                                        powersupply to work with it. So I managed to scan the pages :) (there are
                                        2).

                                        The files are in a zip file of about 3Mb. Mail me your e-mail address and
                                        I'll send it to you. Or maybe they can be hosted in cosmacelf yahoogroups?

                                        My e-mail is peterv[*at*]jaytown[*dot*]com.

                                        PeterV


                                        ---
                                        Outgoing mail is certified Virus Free.
                                        Checked by AVG anti-virus system (http://www.grisoft.com).
                                        Version: 6.0.698 / Virus Database: 455 - Release Date: 2-6-2004
                                      • david dirilo
                                        I d like the zip file. email:weenamon@yahoo.com David D. ... __________________________________ Do you Yahoo!? Friends. Fun. Try the all-new Yahoo!
                                        Message 19 of 29 , Jun 8, 2004
                                        • 0 Attachment
                                          I'd like the zip file.
                                          email:weenamon@...
                                          David D.
                                          --- Peter de Vroomen <peterv@...> wrote:
                                          > > > I'll scan it if there's an interest.
                                          > >
                                          > > I would personally love to see a scan!
                                          >
                                          > Ok, the trouble was that my scanner's powersupply
                                          > died, but I hacked another
                                          > powersupply to work with it. So I managed to scan
                                          > the pages :) (there are
                                          > 2).
                                          >
                                          > The files are in a zip file of about 3Mb. Mail me
                                          > your e-mail address and
                                          > I'll send it to you. Or maybe they can be hosted in
                                          > cosmacelf yahoogroups?
                                          >
                                          > My e-mail is peterv[*at*]jaytown[*dot*]com.
                                          >
                                          > PeterV
                                          >
                                          >
                                          > ---
                                          > Outgoing mail is certified Virus Free.
                                          > Checked by AVG anti-virus system
                                          > (http://www.grisoft.com).
                                          > Version: 6.0.698 / Virus Database: 455 - Release
                                          > Date: 2-6-2004
                                          >
                                          >





                                          __________________________________
                                          Do you Yahoo!?
                                          Friends. Fun. Try the all-new Yahoo! Messenger.
                                          http://messenger.yahoo.com/
                                        Your message has been successfully submitted and would be delivered to recipients shortly.