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

Cromemco People in the Audience?

Expand Messages
  • B. Degnan
    I have just started working on a Cromemco System One that has been in my to-do pile for a while. It s in nice cosmetic shape, but it needs some reverse
    Message 1 of 5 , Nov 30, 2006
    • 0 Attachment
      I have just started working on a Cromemco System One that has been in my
      to-do pile for a while. It's in nice cosmetic shape, but it needs some
      reverse engineering. If anyone is interested, here is a link to pics:

      vintagecomputer.net/browse_thread.cfm?id=41

      There are plenty of docs on the web fortunately. Anyone have one of
      these that would not mind sending me a snapshot of the inside-back cabling?

      Bill
    • Bill Sudbrink
      I use cromemco cards in one of my IMSAIs. The console serial port is on the 16FDC. You want the 25 pin connector on it going to a DB25 on the back. That
      Message 2 of 5 , Nov 30, 2006
      • 0 Attachment
        I use cromemco cards in one of my IMSAIs. The console serial
        port is on the 16FDC. You want the 25 pin connector on it going
        to a DB25 on the back. That will then attach to a terminal. The
        machine will boot up into RDOS (the ROM on the 16FDC) if the
        ZPU has its switch set to jump to C000 on start. The serial port
        and the RDOS start up code will auto sync to whatever BAUD
        rate your terminal is set to from 110-9600, you have to press return
        a few times to get it to sync.

        > -----Original Message-----
        > From: midatlanticretro@yahoogroups.com
        > [mailto:midatlanticretro@yahoogroups.com]On Behalf Of B. Degnan
        > Sent: Thursday, November 30, 2006 7:12 PM
        > To: midatlanticretro@yahoogroups.com
        > Subject: [midatlanticretro] Cromemco People in the Audience?
        >
        >
        > I have just started working on a Cromemco System One that has been in my
        > to-do pile for a while. It's in nice cosmetic shape, but it needs some
        > reverse engineering. If anyone is interested, here is a link to pics:
        >
        > vintagecomputer.net/browse_thread.cfm?id=41
        >
        > There are plenty of docs on the web fortunately. Anyone have one of
        > these that would not mind sending me a snapshot of the
        > inside-back cabling?
        >
        > Bill
        >
        >
        >
        >
        >
        > Yahoo! Groups Links
        >
        >
        >
        > --
        > No virus found in this incoming message.
        > Checked by AVG Free Edition.
        > Version: 7.1.409 / Virus Database: 268.15.2/559 - Release Date: 11/30/2006
        >
        --
        No virus found in this outgoing message.
        Checked by AVG Free Edition.
        Version: 7.1.409 / Virus Database: 268.15.2/559 - Release Date: 11/30/2006
      • B. Degnan
        Bill, Thanks. I had not checked the ZPU doc yet, getting to the RDOS ROM would be a start. Two of the pins on the RDOS are soldered together, unsure why, the
        Message 3 of 5 , Nov 30, 2006
        • 0 Attachment
          Bill,
          Thanks. I had not checked the ZPU doc yet, getting to the RDOS ROM would
          be a start. Two of the pins on the RDOS are soldered together, unsure why,
          the picture I have on my site does not show this. I had tried to get
          anything to return on the terminal, but no result. It seems like power is
          OK, the system is in really nice shape. Almost like it broke down within a
          year or so and no one ever bothered to try to fix it. Hmmm.
          Bill

          At 10:05 PM 11/30/2006 -0500, you wrote:
          >I use cromemco cards in one of my IMSAIs. The console serial
          >port is on the 16FDC. You want the 25 pin connector on it going
          >to a DB25 on the back. That will then attach to a terminal. The
          >machine will boot up into RDOS (the ROM on the 16FDC) if the
          >ZPU has its switch set to jump to C000 on start. The serial port
          >and the RDOS start up code will auto sync to whatever BAUD
          >rate your terminal is set to from 110-9600, you have to press return
          >a few times to get it to sync.
        • Bill Sudbrink
          The 16FDC design calls for lower density masked ROMs. As the higher density ROMs got cheaper, cormemco switched over to using them. The pins that are tied
          Message 4 of 5 , Dec 1, 2006
          • 0 Attachment
            The 16FDC design calls for lower density masked ROMs. As the higher density
            ROMs got cheaper, cormemco switched over to using them. The pins that are
            tied together are just unused address pins on the high density ROM. Things
            to
            check:
            1 make sure that the "start address" switches on the ZPU are set correctly
            2 make sure that you are using the right DB25 connector (should be just a
            straight
            through cable) and that the cable to your terminal is "right way around",
            that is
            the TXD/RXD orientation of pins 2 and 3. I can never remember when you
            want
            DCE (Data Computer Equipment) or DTE (Data Terminal Equipment). You
            really
            only need TXD, RXD and ground (pin 7) between the computer and the
            terminal.
            Try sticking a NULL modem converter in the path and see if that helps.
            3 leave out everything except the ZPU, 16FDC and the 64KZ
            4 be sure the 64KZ is set to bank 0 (zero)
            5 check voltage levels on the bus
            6 gently "rock" (ease out and reinsert) socketed chips, especially TI (Texas
            Instruments) chips with tarnished pins.

            > -----Original Message-----
            > From: midatlanticretro@yahoogroups.com
            > [mailto:midatlanticretro@yahoogroups.com]On Behalf Of B. Degnan
            > Sent: Thursday, November 30, 2006 11:53 PM
            > To: midatlanticretro@yahoogroups.com
            > Subject: RE: [midatlanticretro] Cromemco People in the Audience?
            >
            >
            > Bill,
            > Thanks. I had not checked the ZPU doc yet, getting to the RDOS ROM would
            > be a start. Two of the pins on the RDOS are soldered together,
            > unsure why,
            > the picture I have on my site does not show this. I had tried to get
            > anything to return on the terminal, but no result. It seems
            > like power is
            > OK, the system is in really nice shape. Almost like it broke
            > down within a
            > year or so and no one ever bothered to try to fix it. Hmmm.
            > Bill
            >
            > At 10:05 PM 11/30/2006 -0500, you wrote:
            > >I use cromemco cards in one of my IMSAIs. The console serial
            > >port is on the 16FDC. You want the 25 pin connector on it going
            > >to a DB25 on the back. That will then attach to a terminal. The
            > >machine will boot up into RDOS (the ROM on the 16FDC) if the
            > >ZPU has its switch set to jump to C000 on start. The serial port
            > >and the RDOS start up code will auto sync to whatever BAUD
            > >rate your terminal is set to from 110-9600, you have to press return
            > >a few times to get it to sync.
            >
            >
            >
            >
            >
            > Yahoo! Groups Links
            >
            >
            >
            > --
            > No virus found in this incoming message.
            > Checked by AVG Free Edition.
            > Version: 7.1.409 / Virus Database: 268.15.2/559 - Release Date: 11/30/2006
            >
            --
            No virus found in this outgoing message.
            Checked by AVG Free Edition.
            Version: 7.1.409 / Virus Database: 268.15.3/561 - Release Date: 12/1/2006
          • B. Degnan
            Bill, Thanks. I will let you know. Bill
            Message 5 of 5 , Dec 1, 2006
            • 0 Attachment
              Bill,
              Thanks. I will let you know.
              Bill

              At 06:53 AM 12/1/2006 -0500, you wrote:
              >The 16FDC design calls for lower density masked ROMs. As the higher density
              >ROMs got cheaper, cormemco switched over to using them. The pins that are
              >tied together are just unused address pins on the high density ROM. Things
              >to
              >check:
              >1 make sure that the "start address" switches on the ZPU are set correctly
              >2 make sure that you are using the right DB25 connector (should be just a
              >straight
              > through cable) and that the cable to your terminal is "right way around",
              >that is
              > the TXD/RXD orientation of pins 2 and 3. I can never remember when you
              >want
              > DCE (Data Computer Equipment) or DTE (Data Terminal Equipment). You
              >really
              > only need TXD, RXD and ground (pin 7) between the computer and the
              >terminal.
              > Try sticking a NULL modem converter in the path and see if that helps.
              >3 leave out everything except the ZPU, 16FDC and the 64KZ
              >4 be sure the 64KZ is set to bank 0 (zero)
              >5 check voltage levels on the bus
              >6 gently "rock" (ease out and reinsert) socketed chips, especially TI (Texas
              > Instruments) chips with tarnished pins.
            Your message has been successfully submitted and would be delivered to recipients shortly.