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Re: Apple II Troubleshooting Question

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  • buseyl
    You should check out 1000Bit. In the manual section they have the Apple ][ Reference manual and a whole lot more (other comps too)! The best book for a
    Message 1 of 20 , Aug 30, 2006
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      You should check out 1000Bit. In the manual section they have the
      Apple ][ Reference manual and a whole lot more (other comps too)! The
      best book for a thurough understanding of how the Apple II works is
      "Understanding the Apple II" which is also available. It's extremely
      popular with the crowd on CSA2.

      www.1000bit.net

      Liam Busey


      --- In midatlanticretro@yahoogroups.com, Bob Grieb <bobgrieb@...> wrote:
      >
      > If anyone has an Apple ][ manual, the schematic is
      > included. So far I have not found a copy of it on the
      > web.
      >
      > Bob A - Do you have an Apple II manual?
      >
      > Bob Grieb
      >
      > --- macmothership <macmothership@...> wrote:
      >
      > > Last week I finilly aquired an original Apple II. I have had a II+
      > > for some time, but just
      > > never found an origiinal II for the right price. But this one has a
      > > problem that I'm hoping
      > > someone can help me with.
      > >
      > > • The computer turns on with a normal beep.
      > > • The monitor lights up, but with a set of maybe 4 pixel wide bars a
      > > pixel or so two apart vertically up the screen. In the lower left
      > > there
      > > is a blinking "cursor", which is actually a block of pixels the size
      > > of a character in the second bar, that blinks like a cursor.
      > > • The "cursor responds to keyboard input by moving to the right just
      > > like it should, but no text.
      > > The reset button functions normally, with a beep and a "return" of
      > > the cursor on screen.
      > > • "Control + G" rings the bell
      > > • Typing "Load + Return" cycles through about 10 lines and goes back
      > > to the blinking "cursor"
      > >
      > > Over the weekend, I switched out every chip that is socketed from the
      > > Apple II+ to the apple II one section or row at a time. I did RAM,
      > > ROMS, processor, everything. (that was a tedious job!)
      > > Each and every time there was no change in the symptoms. Also, I
      > > tried the II+ power supply and keyboard. I checked the bottom of the
      > > board for anything strange, but didn't see anything that looks out of
      > > wack.
      > >
      > > It almost seems like a fault in the location that takes the
      > > processor output and keyboard input and converts it or decodes it to
      > > ASCII characters for display on the video. If there is such a place,
      > > I'm just guessing, I'm not good at the component level.
      > >
      > > At this point, would you start to replace solid-state components,
      > > like resistors, capacitors and transistors? I'm not sure there is
      > > anything else left! Unless it is one of the couple of smaller chips
      > > (one near the video out, for example) that are soldered on the II+,
      > > but not on the II, and I couldn't switch.
      > >
      > > Any and all help would be greatly appreciated!
      > >
      > > Thanks,
      > > Jim
      > >
      > >
      > >
      > >
      > >
      >
      >
      > __________________________________________________
      > Do You Yahoo!?
      > Tired of spam? Yahoo! Mail has the best spam protection around
      > http://mail.yahoo.com
      >
    • buseyl
      Hi Jim, I just read about your Apple troubles (I get the digest). It s kind of late tonight but maybe I can help. I have an Apple ][ rev 0 and an Apple ][+
      Message 2 of 20 , Aug 30, 2006
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        Hi Jim, I just read about your Apple troubles (I get the digest). It's
        kind of late tonight but maybe I can help. I have an Apple ][ rev 0
        and an Apple ][+ rev RFI D. All revisions of the Apple and Apple ][+
        are very similar but there are differences so you should be careful
        about swapping parts. For instance, the character generator in IIRC
        rev 7 Apples on up was changed to be pin compatible with a 2716 EPROM
        to allow for custom character sets. If you swap incompatible character
        generators something could get cooked. Do you know what revs your ][
        and ][+ motherboards are? Do you know firmware does your Apple has
        (autostart or old monitor, integer or Applesoft BASIC)?

        Good news. You get video, can move the cursor with the keyboard, and
        get the machine to beep with ctrl-G so your Apple mostly works. I
        wonder. Are you using a color monitor with your ][? Is the garbage
        color (lores) or mono (text)? I'd be curious to see if hires is
        working. The Applevision demo on the DOS 3.3 System Master disk would
        probably give you a good idea but that may be hard to type in blind.

        There're a lot of knowledgeable people here. I think the prognosis for
        your Apple is good.

        Liam

        --- In midatlanticretro@yahoogroups.com, "macmothership"
        <macmothership@...> wrote:
        >
        > I just want to say thanks to everyone who has taken the time to
        respond. It really means
        > alot to me, and when I eventually get this one working it will be
        quite a pleasure to display
        > it at upcoming MARCH events. It took me a long time to find an Apple
        II and I had almost
        > given up hope, so I had to jump on this one, even though it had
        problems. Cosmetically it
        > is quite good. Thanks again for your help so far.
        >
        > Jim
        >
        > --- In midatlanticretro@yahoogroups.com, BOYD BORRILL <b.r.borrill@>
        wrote:
        > >
        > > Hi Evan;
        > > I've been following this thread all day and would like to make
        an offer. I have a book
        > published by SAMS, entitled "The Apple II Circuit Description" by
        Winston D. Gaylor.
        > > It is abut 2 inches thick, spiral bound and contains a complete
        set of circuit
        > descriptions for every revision of the Apple II from the olriginal
        through the Apple II +. It
        > includes timing diagrams, waveforms, keyboard differences and
        circuit/logic diagrams. It
        > thorolughly covers circuit analysis and how to tell the differences
        by the numbers of the
        > various models.
        > > I have sold two copies of this book on E-bay for up to $55.00. I
        recently found this
        > copy in a local thrift store and bought it. Considering the content
        of this thread I would
        > like to offer the following: I will give this book to MARCH as a
        contribution to pay my initial
        > financial offering (because I have no cash anymore). I would suggest
        that MARCH make it
        > available to members as needed, like a "lending Library" and
        otherwise keep it displayed in
        > the museum. It would save a lot of internet searching.
        > > Given a p;ositive response from you, and a mailing address, I
        could have it in your
        > hands in about a week.
        > > Ray
        > >
        > > Evan Koblentz <evan@> wrote:
        > > I'd guess that someone on classiccmp must have it.
        Perhaps someone like
        > > Hans Franke...?
        > >
        > > Or how about you, Tom Owad?
        > >
        > > Or just send an email to Sellam (sellam@) .... He'll either
        > > have it or know who does.
        > >
        > > -----Original Message-----
        > > From: Bob Grieb [mailto:bobgrieb@]
        > > Sent: Tuesday, August 29, 2006 1:15 PM
        > > To: midatlanticretro@yahoogroups.com
        > > Subject: Re: [midatlanticretro] Apple II Troubleshooting Question
        > >
        > > If anyone has an Apple ][ manual, the schematic is included. So
        far I have
        > > not found a copy of it on the web.
        > >
        > > Bob A - Do you have an Apple II manual?
        > >
        > > Bob Grieb
        > >
        > > --- macmothership <macmothership@> wrote:
        > >
        > > > Last week I finilly aquired an original Apple II. I have had a
        II+ for
        > > > some time, but just never found an origiinal II for the right
        price.
        > > > But this one has a problem that I'm hoping someone can help me with.
        > > >
        > > > . The computer turns on with a normal beep.
        > > > . The monitor lights up, but with a set of maybe 4 pixel wide
        bars a
        > > > pixel or so two apart vertically up the screen. In the lower left
        > > > there is a blinking "cursor", which is actually a block of
        pixels the
        > > > size of a character in the second bar, that blinks like a cursor.
        > > > . The "cursor responds to keyboard input by moving to the right
        just
        > > > like it should, but no text.
        > > > The reset button functions normally, with a beep and a "return"
        of the
        > > > cursor on screen.
        > > > . "Control + G" rings the bell
        > > > . Typing "Load + Return" cycles through about 10 lines and goes
        back
        > > > to the blinking "cursor"
        > > >
        > > > Over the weekend, I switched out every chip that is socketed
        from the
        > > > Apple II+ to the apple II one section or row at a time. I did RAM,
        > > > ROMS, processor, everything. (that was a tedious job!) Each and
        every
        > > > time there was no change in the symptoms. Also, I tried the II+
        power
        > > > supply and keyboard. I checked the bottom of the board for anything
        > > > strange, but didn't see anything that looks out of wack.
        > > >
        > > > It almost seems like a fault in the location that takes the
        processor
        > > > output and keyboard input and converts it or decodes it to ASCII
        > > > characters for display on the video. If there is such a place, I'm
        > > > just guessing, I'm not good at the component level.
        > > >
        > > > At this point, would you start to replace solid-state
        components, like
        > > > resistors, capacitors and transistors? I'm not sure there is
        anything
        > > > else left! Unless it is one of the couple of smaller chips (one
        near
        > > > the video out, for example) that are soldered on the II+, but
        not on
        > > > the II, and I couldn't switch.
        > > >
        > > > Any and all help would be greatly appreciated!
        > > >
        > > > Thanks,
        > > > Jim
        > > >
        > > >
        > > >
        > > >
        > > >
        > >
        > > __________________________________________________
        > > Do You Yahoo!?
        > > Tired of spam? Yahoo! Mail has the best spam protection around
        > > http://mail.yahoo.com
        > >
        > > Yahoo! Groups Links
        > >
        > >
        > >
        > >
        > >
        > >
        > > Pioneer Purveyor of Personal Processing Power
        > >
        >
      • macmothership
        I m going to try Herb s suggestion to see if it reads a disk, but I suspect it will. It seems to function. I just got a complete new ROM set I am going to try
        Message 3 of 20 , Aug 31, 2006
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          I'm going to try Herb's suggestion to see if it reads a disk, but I suspect it will. It seems to
          function. I just got a complete new ROM set I am going to try as well, although swapping
          with the II+ didn't change the symptoms.
          I've had a suggestion that the charactor ROM may be the problem. Is that the charactor
          generator that you mention? The large chip under the keyboard location?

          I did swap this with the II+ when doing the chip swap with no change in symptoms. The
          chip in the II looks weird, though. It is brown, has a clear circular window in the middle,
          and is marked with a large lower case letter i. But as I said swapping it didn't change
          anything.

          I know the Apple II isn't a REV 0 (It has the extra pin behind the video port) but other than
          that, I don't know any other details. I am using the B&W (green, actually) Apple tilting
          monitor

          Thanks!
          Jim




          --- In midatlanticretro@yahoogroups.com, "buseyl" <buseyl@...> wrote:
          >
          > Hi Jim, I just read about your Apple troubles (I get the digest). It's
          > kind of late tonight but maybe I can help. I have an Apple ][ rev 0
          > and an Apple ][+ rev RFI D. All revisions of the Apple and Apple ][+
          > are very similar but there are differences so you should be careful
          > about swapping parts. For instance, the character generator in IIRC
          > rev 7 Apples on up was changed to be pin compatible with a 2716 EPROM
          > to allow for custom character sets. If you swap incompatible character
          > generators something could get cooked. Do you know what revs your ][
          > and ][+ motherboards are? Do you know firmware does your Apple has
          > (autostart or old monitor, integer or Applesoft BASIC)?
          >
          > Good news. You get video, can move the cursor with the keyboard, and
          > get the machine to beep with ctrl-G so your Apple mostly works. I
          > wonder. Are you using a color monitor with your ][? Is the garbage
          > color (lores) or mono (text)? I'd be curious to see if hires is
          > working. The Applevision demo on the DOS 3.3 System Master disk would
          > probably give you a good idea but that may be hard to type in blind.
          >
          > There're a lot of knowledgeable people here. I think the prognosis for
          > your Apple is good.
          >
          > Liam
          >
          > --- In midatlanticretro@yahoogroups.com, "macmothership"
          > <macmothership@> wrote:
          > >
          > > I just want to say thanks to everyone who has taken the time to
          > respond. It really means
          > > alot to me, and when I eventually get this one working it will be
          > quite a pleasure to display
          > > it at upcoming MARCH events. It took me a long time to find an Apple
          > II and I had almost
          > > given up hope, so I had to jump on this one, even though it had
          > problems. Cosmetically it
          > > is quite good. Thanks again for your help so far.
          > >
          > > Jim
          > >
          > > --- In midatlanticretro@yahoogroups.com, BOYD BORRILL <b.r.borrill@>
          > wrote:
          > > >
          > > > Hi Evan;
          > > > I've been following this thread all day and would like to make
          > an offer. I have a book
          > > published by SAMS, entitled "The Apple II Circuit Description" by
          > Winston D. Gaylor.
          > > > It is abut 2 inches thick, spiral bound and contains a complete
          > set of circuit
          > > descriptions for every revision of the Apple II from the olriginal
          > through the Apple II +. It
          > > includes timing diagrams, waveforms, keyboard differences and
          > circuit/logic diagrams. It
          > > thorolughly covers circuit analysis and how to tell the differences
          > by the numbers of the
          > > various models.
          > > > I have sold two copies of this book on E-bay for up to $55.00. I
          > recently found this
          > > copy in a local thrift store and bought it. Considering the content
          > of this thread I would
          > > like to offer the following: I will give this book to MARCH as a
          > contribution to pay my initial
          > > financial offering (because I have no cash anymore). I would suggest
          > that MARCH make it
          > > available to members as needed, like a "lending Library" and
          > otherwise keep it displayed in
          > > the museum. It would save a lot of internet searching.
          > > > Given a p;ositive response from you, and a mailing address, I
          > could have it in your
          > > hands in about a week.
          > > > Ray
          > > >
          > > > Evan Koblentz <evan@> wrote:
          > > > I'd guess that someone on classiccmp must have it.
          > Perhaps someone like
          > > > Hans Franke...?
          > > >
          > > > Or how about you, Tom Owad?
          > > >
          > > > Or just send an email to Sellam (sellam@) .... He'll either
          > > > have it or know who does.
          > > >
          > > > -----Original Message-----
          > > > From: Bob Grieb [mailto:bobgrieb@]
          > > > Sent: Tuesday, August 29, 2006 1:15 PM
          > > > To: midatlanticretro@yahoogroups.com
          > > > Subject: Re: [midatlanticretro] Apple II Troubleshooting Question
          > > >
          > > > If anyone has an Apple ][ manual, the schematic is included. So
          > far I have
          > > > not found a copy of it on the web.
          > > >
          > > > Bob A - Do you have an Apple II manual?
          > > >
          > > > Bob Grieb
          > > >
          > > > --- macmothership <macmothership@> wrote:
          > > >
          > > > > Last week I finilly aquired an original Apple II. I have had a
          > II+ for
          > > > > some time, but just never found an origiinal II for the right
          > price.
          > > > > But this one has a problem that I'm hoping someone can help me with.
          > > > >
          > > > > . The computer turns on with a normal beep.
          > > > > . The monitor lights up, but with a set of maybe 4 pixel wide
          > bars a
          > > > > pixel or so two apart vertically up the screen. In the lower left
          > > > > there is a blinking "cursor", which is actually a block of
          > pixels the
          > > > > size of a character in the second bar, that blinks like a cursor.
          > > > > . The "cursor responds to keyboard input by moving to the right
          > just
          > > > > like it should, but no text.
          > > > > The reset button functions normally, with a beep and a "return"
          > of the
          > > > > cursor on screen.
          > > > > . "Control + G" rings the bell
          > > > > . Typing "Load + Return" cycles through about 10 lines and goes
          > back
          > > > > to the blinking "cursor"
          > > > >
          > > > > Over the weekend, I switched out every chip that is socketed
          > from the
          > > > > Apple II+ to the apple II one section or row at a time. I did RAM,
          > > > > ROMS, processor, everything. (that was a tedious job!) Each and
          > every
          > > > > time there was no change in the symptoms. Also, I tried the II+
          > power
          > > > > supply and keyboard. I checked the bottom of the board for anything
          > > > > strange, but didn't see anything that looks out of wack.
          > > > >
          > > > > It almost seems like a fault in the location that takes the
          > processor
          > > > > output and keyboard input and converts it or decodes it to ASCII
          > > > > characters for display on the video. If there is such a place, I'm
          > > > > just guessing, I'm not good at the component level.
          > > > >
          > > > > At this point, would you start to replace solid-state
          > components, like
          > > > > resistors, capacitors and transistors? I'm not sure there is
          > anything
          > > > > else left! Unless it is one of the couple of smaller chips (one
          > near
          > > > > the video out, for example) that are soldered on the II+, but
          > not on
          > > > > the II, and I couldn't switch.
          > > > >
          > > > > Any and all help would be greatly appreciated!
          > > > >
          > > > > Thanks,
          > > > > Jim
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > >
          > > > __________________________________________________
          > > > Do You Yahoo!?
          > > > Tired of spam? Yahoo! Mail has the best spam protection around
          > > > http://mail.yahoo.com
          > > >
          > > > Yahoo! Groups Links
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > > Pioneer Purveyor of Personal Processing Power
          > > >
          > >
          >
        • Bob Grieb
          Jim, If you go to www.1000bit.net, then to the manuals section, and select Apple, you can find a complete copy of the Apple ][ ref manual. Unfortunately, the
          Message 4 of 20 , Aug 31, 2006
          • 0 Attachment
            Jim,

            If you go to www.1000bit.net, then to the manuals
            section, and select Apple, you can find a complete
            copy of the Apple ][ ref manual. Unfortunately, the
            scanning job is not great so the schematics are
            pretty much unusable, but it also has a description of
            how the video section works.

            I downloaded something called
            the Apple II mini manual, and on page 60 it has a
            complete schem of just the video circuit. This should
            help you to see how things are set up. A5 is the location
            on the circuit board of the char gen EPROM, a 2513 type.

            With a 'scope and this schem, you should be able to
            see what's not working.

            Bob Grieb

            --- macmothership <macmothership@...> wrote:

            > I'm going to try Herb's suggestion to see if it reads a disk, but I
            > suspect it will. It seems to
            > function. I just got a complete new ROM set I am going to try as
            > well, although swapping
            > with the II+ didn't change the symptoms.
            > I've had a suggestion that the charactor ROM may be the problem. Is
            > that the charactor
            > generator that you mention? The large chip under the keyboard
            > location?
            >
            > I did swap this with the II+ when doing the chip swap with no change
            > in symptoms. The
            > chip in the II looks weird, though. It is brown, has a clear circular
            > window in the middle,
            > and is marked with a large lower case letter i. But as I said
            > swapping it didn't change
            > anything.
            >
            > I know the Apple II isn't a REV 0 (It has the extra pin behind the
            > video port) but other than
            > that, I don't know any other details. I am using the B&W (green,
            > actually) Apple tilting
            > monitor
            >
            > Thanks!
            > Jim
            >
            >
            >
            >
            > --- In midatlanticretro@yahoogroups.com, "buseyl" <buseyl@...> wrote:
            > >
            > > Hi Jim, I just read about your Apple troubles (I get the digest).
            > It's
            > > kind of late tonight but maybe I can help. I have an Apple ][ rev 0
            > > and an Apple ][+ rev RFI D. All revisions of the Apple and Apple
            > ][+
            > > are very similar but there are differences so you should be careful
            > > about swapping parts. For instance, the character generator in IIRC
            > > rev 7 Apples on up was changed to be pin compatible with a 2716
            > EPROM
            > > to allow for custom character sets. If you swap incompatible
            > character
            > > generators something could get cooked. Do you know what revs your
            > ][
            > > and ][+ motherboards are? Do you know firmware does your Apple has
            > > (autostart or old monitor, integer or Applesoft BASIC)?
            > >
            > > Good news. You get video, can move the cursor with the keyboard,
            > and
            > > get the machine to beep with ctrl-G so your Apple mostly works. I
            > > wonder. Are you using a color monitor with your ][? Is the garbage
            > > color (lores) or mono (text)? I'd be curious to see if hires is
            > > working. The Applevision demo on the DOS 3.3 System Master disk
            > would
            > > probably give you a good idea but that may be hard to type in
            > blind.
            > >
            > > There're a lot of knowledgeable people here. I think the prognosis
            > for
            > > your Apple is good.
            > >
            > > Liam
            > >
            > > --- In midatlanticretro@yahoogroups.com, "macmothership"
            > > <macmothership@> wrote:
            > > >
            > > > I just want to say thanks to everyone who has taken the time to
            > > respond. It really means
            > > > alot to me, and when I eventually get this one working it will be
            > > quite a pleasure to display
            > > > it at upcoming MARCH events. It took me a long time to find an
            > Apple
            > > II and I had almost
            > > > given up hope, so I had to jump on this one, even though it had
            > > problems. Cosmetically it
            > > > is quite good. Thanks again for your help so far.
            > > >
            > > > Jim
            > > >
            > > > --- In midatlanticretro@yahoogroups.com, BOYD BORRILL
            > <b.r.borrill@>
            > > wrote:
            > > > >
            > > > > Hi Evan;
            > > > > I've been following this thread all day and would like to
            > make
            > > an offer. I have a book
            > > > published by SAMS, entitled "The Apple II Circuit Description" by
            > > Winston D. Gaylor.
            > > > > It is abut 2 inches thick, spiral bound and contains a
            > complete
            > > set of circuit
            > > > descriptions for every revision of the Apple II from the
            > olriginal
            > > through the Apple II +. It
            > > > includes timing diagrams, waveforms, keyboard differences and
            > > circuit/logic diagrams. It
            > > > thorolughly covers circuit analysis and how to tell the
            > differences
            > > by the numbers of the
            > > > various models.
            > > > > I have sold two copies of this book on E-bay for up to
            > $55.00. I
            > > recently found this
            > > > copy in a local thrift store and bought it. Considering the
            > content
            > > of this thread I would
            > > > like to offer the following: I will give this book to MARCH as a
            > > contribution to pay my initial
            > > > financial offering (because I have no cash anymore). I would
            > suggest
            > > that MARCH make it
            > > > available to members as needed, like a "lending Library" and
            > > otherwise keep it displayed in
            > > > the museum. It would save a lot of internet searching.
            > > > > Given a p;ositive response from you, and a mailing address, I
            > > could have it in your
            > > > hands in about a week.
            > > > > Ray
            > > > >
            > > > > Evan Koblentz <evan@> wrote:
            > > > > I'd guess that someone on classiccmp must have it.
            > > Perhaps someone like
            > > > > Hans Franke...?
            > > > >
            > > > > Or how about you, Tom Owad?
            > > > >
            > > > > Or just send an email to Sellam (sellam@) .... He'll either
            > > > > have it or know who does.
            > > > >
            > > > > -----Original Message-----
            > > > > From: Bob Grieb [mailto:bobgrieb@]
            > > > > Sent: Tuesday, August 29, 2006 1:15 PM
            > > > > To: midatlanticretro@yahoogroups.com
            > > > > Subject: Re: [midatlanticretro] Apple II Troubleshooting
            > Question
            > > > >
            > > > > If anyone has an Apple ][ manual, the schematic is included. So
            > > far I have
            > > > > not found a copy of it on the web.
            > > > >
            > > > > Bob A - Do you have an Apple II manual?
            > > > >
            > > > > Bob Grieb
            > > > >
            > > > > --- macmothership <macmothership@> wrote:
            > > > >
            > > > > > Last week I finilly aquired an original Apple II. I have had
            > a
            > > II+ for
            > > > > > some time, but just never found an origiinal II for the right
            > > price.
            > > > > > But this one has a problem that I'm hoping someone can help
            > me with.
            > > > > >
            > > > > > . The computer turns on with a normal beep.
            > > > > > . The monitor lights up, but with a set of maybe 4 pixel wide
            > > bars a
            > > > > > pixel or so two apart vertically up the screen. In the lower
            > left
            > > > > > there is a blinking "cursor", which is actually a block of
            > > pixels the
            > > > > > size of a character in the second bar, that blinks like a
            > cursor.
            > > > > > . The "cursor responds to keyboard input by moving to the
            > right
            > > just
            > > > > > like it should, but no text.
            > > > > > The reset button functions normally, with a beep and a
            > "return"
            > > of the
            > > > > > cursor on screen.
            > > > > > . "Control + G" rings the bell
            > > > > > . Typing "Load + Return" cycles through about 10 lines and
            > goes
            > > back
            > > > > > to the blinking "cursor"
            > > > > >
            > > > > > Over the weekend, I switched out every chip that is socketed
            > > from the
            > > > > > Apple II+ to the apple II one section or row at a time. I did
            > RAM,
            > > > > > ROMS, processor, everything. (that was a tedious job!) Each
            > and
            > > every
            > > > > > time there was no change in the symptoms. Also, I tried the
            > II+
            > > power
            > > > > > supply and keyboard. I checked the bottom of the board for
            > anything
            > > > > > strange, but didn't see anything that looks out of wack.
            > > > > >
            > > > > > It almost seems like a fault in the location that takes the
            > > processor
            > > > > > output and keyboard input and converts it or decodes it to
            > ASCII
            > > > > > characters for display on the video. If there is such a
            > place, I'm
            > > > > > just guessing, I'm not good at the component level.
            > > > > >
            >
            === message truncated ===


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          • macmothership
            Here is where we are. There is no change in the symptoms to this point. I have swapped every chip with an Apple II+ (except the two 555 s which are soldered on
            Message 5 of 20 , Sep 2, 2006
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              Here is where we are. There is no change in the symptoms to this point.

              I have swapped every chip with an Apple II+ (except the two 555's which are soldered on
              the II+) with the Apple II. No change.

              I have buzzed out every pin on every chip to the solder point under the board for
              continuity. Every single chip pin was ok. (THAT was tedious!)

              I have checked all resistors to the proper value and they all check out.

              It does not try to access the disk drive on booting, like the II+.

              That is about it right now, I'm not sure what to try next. As I think I said before, it had a
              Videx Keyboard and Video Enhancer card installed, which I removed. I called Videx (Still in
              business!) and an old timer dug up a manual and photocopied it for me. He put it in the
              mail, and I should get it this week. I can check that to see what mods may have been done
              to the board, but it really looks like there weren't any.

              Is anyone familiar with this Videx board that may know?

              Any help would be appreciated, as always.

              Jim

              --- In midatlanticretro@yahoogroups.com, Bob Grieb <bobgrieb@...> wrote:
              >
              > Jim,
              >
              > If you go to www.1000bit.net, then to the manuals
              > section, and select Apple, you can find a complete
              > copy of the Apple ][ ref manual. Unfortunately, the
              > scanning job is not great so the schematics are
              > pretty much unusable, but it also has a description of
              > how the video section works.
              >
              > I downloaded something called
              > the Apple II mini manual, and on page 60 it has a
              > complete schem of just the video circuit. This should
              > help you to see how things are set up. A5 is the location
              > on the circuit board of the char gen EPROM, a 2513 type.
              >
              > With a 'scope and this schem, you should be able to
              > see what's not working.
              >
              > Bob Grieb
              >
              > --- macmothership <macmothership@...> wrote:
              >
              > > I'm going to try Herb's suggestion to see if it reads a disk, but I
              > > suspect it will. It seems to
              > > function. I just got a complete new ROM set I am going to try as
              > > well, although swapping
              > > with the II+ didn't change the symptoms.
              > > I've had a suggestion that the charactor ROM may be the problem. Is
              > > that the charactor
              > > generator that you mention? The large chip under the keyboard
              > > location?
              > >
              > > I did swap this with the II+ when doing the chip swap with no change
              > > in symptoms. The
              > > chip in the II looks weird, though. It is brown, has a clear circular
              > > window in the middle,
              > > and is marked with a large lower case letter i. But as I said
              > > swapping it didn't change
              > > anything.
              > >
              > > I know the Apple II isn't a REV 0 (It has the extra pin behind the
              > > video port) but other than
              > > that, I don't know any other details. I am using the B&W (green,
              > > actually) Apple tilting
              > > monitor
              > >
              > > Thanks!
              > > Jim
              > >
              > >
              > >
              > >
              > > --- In midatlanticretro@yahoogroups.com, "buseyl" <buseyl@> wrote:
              > > >
              > > > Hi Jim, I just read about your Apple troubles (I get the digest).
              > > It's
              > > > kind of late tonight but maybe I can help. I have an Apple ][ rev 0
              > > > and an Apple ][+ rev RFI D. All revisions of the Apple and Apple
              > > ][+
              > > > are very similar but there are differences so you should be careful
              > > > about swapping parts. For instance, the character generator in IIRC
              > > > rev 7 Apples on up was changed to be pin compatible with a 2716
              > > EPROM
              > > > to allow for custom character sets. If you swap incompatible
              > > character
              > > > generators something could get cooked. Do you know what revs your
              > > ][
              > > > and ][+ motherboards are? Do you know firmware does your Apple has
              > > > (autostart or old monitor, integer or Applesoft BASIC)?
              > > >
              > > > Good news. You get video, can move the cursor with the keyboard,
              > > and
              > > > get the machine to beep with ctrl-G so your Apple mostly works. I
              > > > wonder. Are you using a color monitor with your ][? Is the garbage
              > > > color (lores) or mono (text)? I'd be curious to see if hires is
              > > > working. The Applevision demo on the DOS 3.3 System Master disk
              > > would
              > > > probably give you a good idea but that may be hard to type in
              > > blind.
              > > >
              > > > There're a lot of knowledgeable people here. I think the prognosis
              > > for
              > > > your Apple is good.
              > > >
              > > > Liam
              > > >
              > > > --- In midatlanticretro@yahoogroups.com, "macmothership"
              > > > <macmothership@> wrote:
              > > > >
              > > > > I just want to say thanks to everyone who has taken the time to
              > > > respond. It really means
              > > > > alot to me, and when I eventually get this one working it will be
              > > > quite a pleasure to display
              > > > > it at upcoming MARCH events. It took me a long time to find an
              > > Apple
              > > > II and I had almost
              > > > > given up hope, so I had to jump on this one, even though it had
              > > > problems. Cosmetically it
              > > > > is quite good. Thanks again for your help so far.
              > > > >
              > > > > Jim
              > > > >
              > > > > --- In midatlanticretro@yahoogroups.com, BOYD BORRILL
              > > <b.r.borrill@>
              > > > wrote:
              > > > > >
              > > > > > Hi Evan;
              > > > > > I've been following this thread all day and would like to
              > > make
              > > > an offer. I have a book
              > > > > published by SAMS, entitled "The Apple II Circuit Description" by
              > > > Winston D. Gaylor.
              > > > > > It is abut 2 inches thick, spiral bound and contains a
              > > complete
              > > > set of circuit
              > > > > descriptions for every revision of the Apple II from the
              > > olriginal
              > > > through the Apple II +. It
              > > > > includes timing diagrams, waveforms, keyboard differences and
              > > > circuit/logic diagrams. It
              > > > > thorolughly covers circuit analysis and how to tell the
              > > differences
              > > > by the numbers of the
              > > > > various models.
              > > > > > I have sold two copies of this book on E-bay for up to
              > > $55.00. I
              > > > recently found this
              > > > > copy in a local thrift store and bought it. Considering the
              > > content
              > > > of this thread I would
              > > > > like to offer the following: I will give this book to MARCH as a
              > > > contribution to pay my initial
              > > > > financial offering (because I have no cash anymore). I would
              > > suggest
              > > > that MARCH make it
              > > > > available to members as needed, like a "lending Library" and
              > > > otherwise keep it displayed in
              > > > > the museum. It would save a lot of internet searching.
              > > > > > Given a p;ositive response from you, and a mailing address, I
              > > > could have it in your
              > > > > hands in about a week.
              > > > > > Ray
              > > > > >
              > > > > > Evan Koblentz <evan@> wrote:
              > > > > > I'd guess that someone on classiccmp must have it.
              > > > Perhaps someone like
              > > > > > Hans Franke...?
              > > > > >
              > > > > > Or how about you, Tom Owad?
              > > > > >
              > > > > > Or just send an email to Sellam (sellam@) .... He'll either
              > > > > > have it or know who does.
              > > > > >
              > > > > > -----Original Message-----
              > > > > > From: Bob Grieb [mailto:bobgrieb@]
              > > > > > Sent: Tuesday, August 29, 2006 1:15 PM
              > > > > > To: midatlanticretro@yahoogroups.com
              > > > > > Subject: Re: [midatlanticretro] Apple II Troubleshooting
              > > Question
              > > > > >
              > > > > > If anyone has an Apple ][ manual, the schematic is included. So
              > > > far I have
              > > > > > not found a copy of it on the web.
              > > > > >
              > > > > > Bob A - Do you have an Apple II manual?
              > > > > >
              > > > > > Bob Grieb
              > > > > >
              > > > > > --- macmothership <macmothership@> wrote:
              > > > > >
              > > > > > > Last week I finilly aquired an original Apple II. I have had
              > > a
              > > > II+ for
              > > > > > > some time, but just never found an origiinal II for the right
              > > > price.
              > > > > > > But this one has a problem that I'm hoping someone can help
              > > me with.
              > > > > > >
              > > > > > > . The computer turns on with a normal beep.
              > > > > > > . The monitor lights up, but with a set of maybe 4 pixel wide
              > > > bars a
              > > > > > > pixel or so two apart vertically up the screen. In the lower
              > > left
              > > > > > > there is a blinking "cursor", which is actually a block of
              > > > pixels the
              > > > > > > size of a character in the second bar, that blinks like a
              > > cursor.
              > > > > > > . The "cursor responds to keyboard input by moving to the
              > > right
              > > > just
              > > > > > > like it should, but no text.
              > > > > > > The reset button functions normally, with a beep and a
              > > "return"
              > > > of the
              > > > > > > cursor on screen.
              > > > > > > . "Control + G" rings the bell
              > > > > > > . Typing "Load + Return" cycles through about 10 lines and
              > > goes
              > > > back
              > > > > > > to the blinking "cursor"
              > > > > > >
              > > > > > > Over the weekend, I switched out every chip that is socketed
              > > > from the
              > > > > > > Apple II+ to the apple II one section or row at a time. I did
              > > RAM,
              > > > > > > ROMS, processor, everything. (that was a tedious job!) Each
              > > and
              > > > every
              > > > > > > time there was no change in the symptoms. Also, I tried the
              > > II+
              > > > power
              > > > > > > supply and keyboard. I checked the bottom of the board for
              > > anything
              > > > > > > strange, but didn't see anything that looks out of wack.
              > > > > > >
              > > > > > > It almost seems like a fault in the location that takes the
              > > > processor
              > > > > > > output and keyboard input and converts it or decodes it to
              > > ASCII
              > > > > > > characters for display on the video. If there is such a
              > > place, I'm
              > > > > > > just guessing, I'm not good at the component level.
              > > > > > >
              > >
              > === message truncated ===
              >
              >
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            • B. Degnan
              Installed in my Apple ][+ I have a Videx expansion card and Videx controller in an IC slot. I think 1980 is printed on the card. To a connector on the
              Message 6 of 20 , Sep 2, 2006
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                Installed in my Apple ][+ I have a Videx expansion card and Videx
                controller in an IC slot.

                I think "1980" is printed on the card. To a connector on the expansion
                card there is a cable connected on the other end to a small Videx
                "expansion controller" board that had been fit into an open IC space near
                the game I/O circuitry.

                The computer itself has a RAM problem so I have not actually used it enough
                to figure out exactly what you get with the Videx card and controller. I
                assume it's for better graphics or gaming.

                As part of testing I removed the Videx cards and it made no difference to
                improve the RAM situation. It's still on the to-be-fixed table. I have
                to do what you did, check each chip, etc. I am in the middle of some other
                projects so I won't be able to get to this until next week.

                FYI - Here is what the screen looks like:

                ???????????
                @@@@@@
                ???????????
                @@@@@@
                etc.

                Bill D


                >That is about it right now, I'm not sure what to try next. As I think I
                >said before, it had a
                >Videx Keyboard and Video Enhancer card installed, which I removed. I
                >called Videx (Still in
                >business!) and an old timer dug up a manual and photocopied it for me. He
                >put it in the
                >mail, and I should get it this week. I can check that to see what mods may
                >have been done
                >to the board, but it really looks like there weren't any.
                >
                >Is anyone familiar with this Videx board that may know?
              • macmothership
                Bill, Sounds like you may have the Enhancer II. Mine was just the single board that piggybacked on the mainboard under the keyboard. Jim
                Message 7 of 20 , Sep 2, 2006
                • 0 Attachment
                  Bill,
                  Sounds like you may have the Enhancer II. Mine was just the single board that piggybacked
                  on the mainboard under the keyboard.
                  Jim

                  --- In midatlanticretro@yahoogroups.com, "B. Degnan" <billdeg@...> wrote:
                  >
                  > Installed in my Apple ][+ I have a Videx expansion card and Videx
                  > controller in an IC slot.
                  >
                  > I think "1980" is printed on the card. To a connector on the expansion
                  > card there is a cable connected on the other end to a small Videx
                  > "expansion controller" board that had been fit into an open IC space near
                  > the game I/O circuitry.
                  >
                  > The computer itself has a RAM problem so I have not actually used it enough
                  > to figure out exactly what you get with the Videx card and controller. I
                  > assume it's for better graphics or gaming.
                  >
                  > As part of testing I removed the Videx cards and it made no difference to
                  > improve the RAM situation. It's still on the to-be-fixed table. I have
                  > to do what you did, check each chip, etc. I am in the middle of some other
                  > projects so I won't be able to get to this until next week.
                  >
                  > FYI - Here is what the screen looks like:
                  >
                  > ???????????
                  > @@@@@@
                  > ???????????
                  > @@@@@@
                  > etc.
                  >
                  > Bill D
                  >
                  >
                  > >That is about it right now, I'm not sure what to try next. As I think I
                  > >said before, it had a
                  > >Videx Keyboard and Video Enhancer card installed, which I removed. I
                  > >called Videx (Still in
                  > >business!) and an old timer dug up a manual and photocopied it for me. He
                  > >put it in the
                  > >mail, and I should get it this week. I can check that to see what mods may
                  > >have been done
                  > >to the board, but it really looks like there weren't any.
                  > >
                  > >Is anyone familiar with this Videx board that may know?
                  >
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