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

Re: [midatlanticretro] ROM gurus

Expand Messages
  • Dan Roganti
    ... You have to make certain of the CS pin logic levels. Table 4 shows only some kind of DIP switch settings. You like to verify the logic in the schematic
    Message 1 of 9 , Jan 31, 2012
    • 0 Attachment




      On Tue, Jan 31, 2012 at 2:17 PM, Mike Loewen <mloewen@...> wrote:

         Ok, ROM gurus...I have a Data I/O 29B with a UniPak2B and a LogicPak:

      http://sturgeon.css.psu.edu/~mloewen/Oldtech/Test/DataIO29B.html

         I would like to be able to read an AMD AM9216BDC mask-programmed ROM,
      but it isn't listed as a supported device.  I've read that it might be
      possible to build an adapter to reroute a couple of pins to allow it to be
      read like a 2716, but have no clue as the specifics.  The 9216 is a 24-pin
      DIP, with dual-active low chip selects, and uses both +5V and +12V.  The
      board these are installed on can use either 9216s or 2716s, but not a mix
      of both.  Here's the info on the ROM board:

      http://bitsavers.org/pdf/hp/terminal/264x/13255-91221_Control_Memory_With_Bank_Select_Module_Oct78.pdf

         Table 4.0 lists the strapping for 9216 vs 2716, and there's a schematic
      at the end.  Any pointers?


      You have to make certain of the CS pin logic levels. Table 4 shows only some kind of DIP switch settings. You like to verify the logic in the schematic where it's used. Just as the firmware is preprogrammed into a Mask Rom at the Factory, these CS pins are also configurable at the factory as either Hi or Lo level inputs by the customer - per their design/schematics. The rest of the chip is straight forward if just you want to read the contents - eg. address, data and power.

      Only these pins are diff from the 2716
          Pin 21= A10
          Pin 20= CS1***
          Pin 19= +12v
          Pin 18= CS1***
      ***check logic level in schematic

      =Dan

    • Dan Roganti
      ... I only looked as far as the page with Table 4, I didn t notice earlier but further in that pdf on page 16, you can see already on this schematic that these
      Message 2 of 9 , Jan 31, 2012
      • 0 Attachment




        On Tue, Jan 31, 2012 at 8:55 PM, Dan Roganti <ragooman@...> wrote:




        On Tue, Jan 31, 2012 at 2:17 PM, Mike Loewen <mloewen@...> wrote:

          The 9216 is a 24-pin
        DIP, with dual-active low chip selects, and uses both +5V and +12V.  The
        board these are installed on can use either 9216s or 2716s, but not a mix
        of both.  Here's the info on the ROM board:

        http://bitsavers.org/pdf/hp/terminal/264x/13255-91221_Control_Memory_With_Bank_Select_Module_Oct78.pdf

           Table 4.0 lists the strapping for 9216 vs 2716, and there's a schematic
        at the end.  Any pointers?


        You have to make certain of the CS pin logic levels. Table 4 shows only some kind of DIP switch settings. You like to verify the logic in the schematic where it's used. Just as the firmware is preprogrammed into a Mask Rom at the Factory, these CS pins are also configurable at the factory as either Hi or Lo level inputs by the customer - per their design/schematics. The rest of the chip is straight forward if just you want to read the contents - eg. address, data and power.

        Only these pins are diff from the 2716
            Pin 21= A10
            Pin 20= CS1***
            Pin 19= +12v
            Pin 18= CS1***
        ***check logic level in schematic



        I only looked as far as the page with Table 4, I didn't notice earlier but further in that pdf on page 16, you can see already on this schematic that these Roms are made with Active Lo inputs on both CS pins. I guess that's where you were looking before when you stated this.

        So pins 18 and 20 on these Roms are not an issue, these are the same as a 2716 - ie, Active Lo inputs. You only have to worry about pins 19 and 21 for your adapter.

        =Dan


      • Jeff Jonas
        ... I m a bit surprised that it isn t listed (pun intended). Perhaps it was on a supplemental list of read-only devices instead of fully supported programmable
        Message 3 of 9 , Jan 31, 2012
        • 0 Attachment
          > > I would like to be able to read an AMD
          > > AM9216BDC mask-programmed ROM,
          > > but it isn't listed as a supported device.

          > While the device isn't supported by the programmer, it's just a 2kx8 ROM with a different pinout. If you connect the data and address lines up, power the chip, and make it active, you can read it.

          I'm a bit surprised that it isn't listed (pun intended). Perhaps it was on a supplemental list of read-only devices instead of fully supported programmable devices, since it's reasonable to clone R/O parts to reprogrammable devices (whether OTP: one time programmable or erasable).

          > First, find the pinout of the 9216 ...

          What he said :-)

          Don't make my cry. :-(
          This would be an ideal extension to current microprocessor tools such as "The Bus Pirate" that connects USB to a variety of serial protocols such as JTAG, SPI, I2C, etc. It should be easy to extend that using I2C buffers to assert the address & read signals and buffer back the result. But I'm hopelessly overloaded with wonderful projects already :-(

          -- jeffj
        • Mike
          This seems similar to the 2316B used in the Apple II. There is an adapter from 2716 to 2316B described on this web page.
          Message 4 of 9 , Feb 2, 2012
          • 0 Attachment
            This seems similar to the 2316B used in the Apple II. There is an adapter from 2716 to 2316B described on this web page.

            http://www.willegal.net/appleii/appleii-integer.htm

            In your case, you will be going in the opposite direction. You would have to get pin outs of 2716 and 9216BDC and rewire a socket to make the pinout of the 9216BCD exactly match that of the 2716. You may need to tweak select line mapping or add an inverter depending upon exact differences/polarities of the select lines.

            Regards,
            Mike Willegal

            --- In midatlanticretro@yahoogroups.com, "Jeff Jonas" <jeff_s_jonas@...> wrote:
            >
            > > > I would like to be able to read an AMD
            > > > AM9216BDC mask-programmed ROM,
            > > > but it isn't listed as a supported device.
            >
            > > While the device isn't supported by the programmer, it's just a 2kx8 ROM with a different pinout. If you connect the data and address lines up, power the chip, and make it active, you can read it.
            >
            > I'm a bit surprised that it isn't listed (pun intended). Perhaps it was on a supplemental list of read-only devices instead of fully supported programmable devices, since it's reasonable to clone R/O parts to reprogrammable devices (whether OTP: one time programmable or erasable).
            >
            > > First, find the pinout of the 9216 ...
            >
            > What he said :-)
            >
            > Don't make my cry. :-(
            > This would be an ideal extension to current microprocessor tools such as "The Bus Pirate" that connects USB to a variety of serial protocols such as JTAG, SPI, I2C, etc. It should be easy to extend that using I2C buffers to assert the address & read signals and buffer back the result. But I'm hopelessly overloaded with wonderful projects already :-(
            >
            > -- jeffj
            >
          • Mike Loewen
            ... Per several of your suggestions, I ended up breadboarding an adapter to make the 9216 look like a 2716 to my 29B. Only 3 changes were needed: Pin 19 (A10)
            Message 5 of 9 , Feb 21, 2012
            • 0 Attachment
              On Tue, 31 Jan 2012, Mike Loewen wrote:

              > Ok, ROM gurus...I have a Data I/O 29B with a UniPak2B and a LogicPak:
              >
              > ...
              >
              > I would like to be able to read an AMD AM9216BDC mask-programmed ROM,
              > but it isn't listed as a supported device. I've read that it might be
              > possible to build an adapter to reroute a couple of pins to allow it to be
              > read like a 2716, but have no clue as the specifics. The 9216 is a 24-pin
              > DIP, with dual-active low chip selects, and uses both +5V and +12V. The
              > board these are installed on can use either 9216s or 2716s, but not a mix
              > of both.>

              Per several of your suggestions, I ended up breadboarding an adapter to
              make the 9216 look like a 2716 to my 29B. Only 3 changes were needed:

              Pin 19 (A10) of the 2716 was redirected to pin 21 of the 9216.
              Pin 21 (Vpp) of the 2716 was left unconnected.
              Pin 21 of the 9216 was connected to a +12V source.

              It works.


              Mike Loewen mloewen@...
              Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
            Your message has been successfully submitted and would be delivered to recipients shortly.