20 Mar
1998
20 Mar
'98
11:37 p.m.
I finally opened up my Kaypros today to see if I could get the '2'
working. The II and the 2 seem to be almost identical inside, with two
notable differences: One of the ROMs has a different number on it, and
my Kaypro II has some wires soldered between pins on one of its chips.
The Kaypro II has a chip with a sticker marked "81-146A", with the
"A"
stamped on in read ink. The Kaypro 2 has a chip with "81-232" on it, in
the same location.
What are the differences?
The chips at position U87 on both motherboards are marked DM74LS390N, but
the one in the Kaypro II has been messed with. It's a 16-pin chip, and
pin 1 has been bent upward and a wire soldered onto it, which leads to pin
6. Pin 9 is missing. Pins 12 and 15 are attached with a wire.
Is this normal for a Kaypro II, or has someone made a modification?
Anyway, I managed to make a copy of the WordStar disk that came in the
drive of the II today, using my Amiga 1000, A1060 SideCar, A1020 5.25"
floppy drive, and TeleDisk. So now I have a disk that boots reliably
instead of 1 out of every 5-10 times. That meant that I now know there's
something wrong with the Kaypro 2, because it won't boot at all with the
new disk. Before, it may have just been a borderline disk that was
causing the problem.
So (tell me if this was a bad/dangerous thing to do) I opened both
machines up and attached them to each others' disk drives. They were
plugged into a power bar, so I powered them up simultaneously with that.
The Kaypro 2 boot up with no problems, using the II's drives, and the II
was incapable of booting using the 2's drives, so I've got the problem
located to drive A of the Kaypro 2 now.
And BTW, both the II and the 2 have full-height drives.
Both keyboards have missing keys (including broken plungers). Will this
be easy to fix?
I'm thinking of fixing the 2, and using the II for parts, simply because I
like the colour of the 2's green phosphor monitor better (and some other
minor things). :) Is one model more rare than the other? IOW, does one
warrant saving more than the other? If not, I'll go with my feeling and
fix the 2 with parts from the II.
Doug Spence
ds_spenc(a)alcor.concordia.ca
21 Mar
21 Mar
1:18 p.m.
On Sat, 21 Mar 1998, Doug Spence wrote:
I finally opened up my Kaypros today to see if I could get the '2'
working. The II and the 2 seem to be almost identical inside, with two
notable differences: One of the ROMs has a different number on it, and
my Kaypro II has some wires soldered between pins on one of its chips.
The Kaypro II has a chip with a sticker marked "81-146A", with the
"A"
stamped on in read ink. The Kaypro 2 has a chip with "81-232" on it, in
the same location.
If the layout of the two boards seem identical, the chip in the II marked
"81-146A", which is the character generator ROM, is in the wrong location
(U47). It should be in U43. The one in U47 should be either "81-149" or
"81-232". They may have gotten swapped.
What are the differences?
The chips at position U87 on both motherboards are marked DM74LS390N, but
the one in the Kaypro II has been messed with. It's a 16-pin chip, and
pin 1 has been bent upward and a wire soldered onto it, which leads to pin
6. Pin 9 is missing. Pins 12 and 15 are attached with a wire.
Is this normal for a Kaypro II, or has someone made a modification?
It is a modification.
Anyway, I managed to make a copy of the WordStar disk
that came in the
drive of the II today, using my Amiga 1000, A1060 SideCar, A1020 5.25"
floppy drive, and TeleDisk. So now I have a disk that boots reliably
instead of 1 out of every 5-10 times. That meant that I now know there's
something wrong with the Kaypro 2, because it won't boot at all with the
new disk. Before, it may have just been a borderline disk that was
causing the problem.
Not necessarily. Unless both machines used the 81-232 boot ROM, there is
every chance that they both will not boot from the same bootable disk.
The boot ROM determines the revision of the operating system required.
So (tell me if this was a bad/dangerous thing to do) I
opened both
machines up and attached them to each others' disk drives. They were
plugged into a power bar, so I powered them up simultaneously with that.
The Kaypro 2 boot up with no problems, using the II's drives, and the II
was incapable of booting using the 2's drives, so I've got the problem
located to drive A of the Kaypro 2 now.
Maybe not. See above.
And BTW, both the II and the 2 have full-height
drives.
Both keyboards have missing keys (including broken plungers). Will this
be easy to fix?
The usual failure mode is for the cruciform projection on the switch
plunger to get broken off. You will need to unsolder the switch and
replace it with a good one. With the benefit of a solder sucker, it is
not necessary to remove the circuit board from the keyboard metal work.
I'm thinking of fixing the 2, and using the II for
parts, simply because I
like the colour of the 2's green phosphor monitor better (and some other
minor things). :) Is one model more rare than the other? IOW, does one
warrant saving more than the other? If not, I'll go with my feeling and
fix the 2 with parts from the II.
The 2 is probably less common.
Doug Spence
ds_spenc(a)alcor.concordia.ca
- don
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
visit the "Unofficial" CP/M Weg site at http://cdl.uta.edu/cpm
with Mirror at http://www.mathcs.emory.edu/~cfs/cpm
12:48 a.m.
New subject: Kaypro 2 Blues
On 21 Mar 98 at 16:18, Don Maslin wrote:
On Sat, 21 Mar 1998, Doug Spence wrote:
>
> I finally opened up my Kaypros today to see if I could get the '2'
> working. The II and the 2 seem to be almost identical inside, with two
> notable differences: One of the ROMs has a different number on it, and
> my Kaypro II has some wires soldered between pins on one of its chips.
>
I've finally figured out I have some sort of symbiotic relationship
with
the Kaypro 2 I've had in my collectionfor several years. The routine goes like
this:
Periodically Ill pull out the "2", plug it in, admire the case and how the kb
fits, fire it up , watch as it acknowledges the B drive then the A. and finally
displays the Kaypro logo on the neat little screen. Then I run through the
disks I got with it starting with the "bootable Wordstar". The disk spins
anndd spins and the logo sits primly staring back at me. Finally I remove the
10 screws holding the cover on and check the connections and tap the chips
to make sure they're seated. Shake my head , "got to be a bad drive or
controler , or maybe it needs a system disk from TCJ" Then I put it back
together , put it back onthe shelf . "Well I'll get to it later" and work
arduously getting my latest acquisition up and working. 3 months later I go
thru the same routine. 8 ^ }
It's symbiotic , man. Wierd people some collectors.
ciao larry
lwalkerN0spaM(a)interlog.com
22 Mar
22 Mar
12:08 a.m.
New subject: Kaypro: 81-149C vs. 81-232
Note: I've changed the subject line to the appropriate chip labels. My
error when posting originally.
On Sat, 21 Mar 1998, Don Maslin wrote:
Sorry about that, the chip in location U47 was "81-149C", not what I
wrote above. I guess I made the error because of the orientation of the
machines - they were connected to each others' drives and thus reversed
front-to-back, and I ran out to the other room to read the labels while in
the middle of the post. I must've read the chip location off one board,
then scanned directly across to the chip on the other board, without
taking into account the reversed orientation. :(
Do you (or anyone else) know if it's a known modification? What I mean
is, does anyone know why this chip might be wired up this way? Does it
solve some known problem with the Kaypro II, or make an enhancement?
Humm... so I've been working from bad assumptions all along. They don't
use the same boot ROM. However, as I mentioned, the Kaypro 2 did boot
<sigh>
Yup. I do have a couple of missing keycaps with good plungers, but
generally I'm looking at what you describe.
I really wish people would treat old hardware better in the Salvation Army
stores. That's where I got both of these machines (at different times),
and from previous observations, that's where I'd guess the damage
occurred.
OK. Considering the differing boot ROMs, though, it's possible that the
only repairs that will need doing will be to the keyboards. I'd rather
save BOTH machines than cannibalize one of them.
I'm hoping the plungers are still made and easily available. Or
salvagable off of something of lesser value, like old PC keyboards.
Thanks for the info, Don!
Doug Spence
ds_spenc(a)alcor.concordia.ca
The Kaypro II
has a chip with a sticker marked "81-146A", with the "A"
stamped on in read ink. The Kaypro 2 has a chip with "81-232" on it, in
the same location.
If the layout of the two boards seem identical, the chip in the II marked
"81-146A", which is the character generator ROM, is in the wrong location
(U47). It should be in U43. The one in U47 should be either "81-149" or
"81-232". They may have gotten swapped. The chips at
position U87 on both motherboards are marked DM74LS390N, but
the one in the Kaypro II has been messed with. It's a 16-pin chip, and
pin 1 has been bent upward and a wire soldered onto it, which leads to pin
6. Pin 9 is missing. Pins 12 and 15 are attached with a wire.
Is this normal for a Kaypro II, or has someone made a modification?
It is a modification. Anyway, I
managed to make a copy of the WordStar disk that came in the
drive of the II today, using my Amiga 1000, A1060 SideCar, A1020 5.25"
floppy drive, and TeleDisk. So now I have a disk that boots reliably
instead of 1 out of every 5-10 times. That meant that I now know there's
something wrong with the Kaypro 2, because it won't boot at all with the
new disk. Before, it may have just been a borderline disk that was
causing the problem.
Not necessarily. Unless both machines used the 81-232 boot ROM, there is
every chance that they both will not boot from the same bootable disk.
The boot ROM determines the revision of the operating system required. from this disk when attached to the II's drives
instead of its own.
Is it possible the drives themselves have different specs that might
interfere as well?
So (tell me if
this was a bad/dangerous thing to do) I opened both
machines up and attached them to each others' disk drives. They were
plugged into a power bar, so I powered them up simultaneously with that.
The Kaypro 2 boot up with no problems, using the II's drives, and the II
was incapable of booting using the 2's drives, so I've got the problem
located to drive A of the Kaypro 2 now.
Maybe not. See above. And BTW, both
the II and the 2 have full-height drives.
Both keyboards have missing keys (including broken plungers). Will this
be easy to fix?
The usual failure mode is for the cruciform projection on the switch
plunger to get broken off. You will need to unsolder the switch and
replace it with a good one. With the benefit of a solder sucker, it is
not necessary to remove the circuit board from the keyboard metal work.
OK. I've had the keyboards open and it doesn't look like an easy job,
though. :/ Looks like time to review Tony's (un)soldering techniques. :)
I'm
thinking of fixing the 2, and using the II for parts, simply because I
like the colour of the 2's green phosphor monitor better (and some other
minor things). :) Is one model more rare than the other? IOW, does one
warrant saving more than the other? If not, I'll go with my feeling and
fix the 2 with parts from the II.
The 2 is probably less common.
1:16 a.m.
New subject: Kaypro: 81-149C vs. 81-232
Well, I've repeated what I did the other night. I plugged the Kaypro II
into the Kaypro 2's drives, and vice versa. Just the ribbon cable, not
the power. Whichever machine was plugged into the Kaypro II's drives was
able to boot, the machine plugged into the 2's drives just sits there with
the bootup message and eventually beeps and says "I cannot read your disk"
(or similar).
I tried swapping the II's 81-149C with the 2's 81-232. Neither will work
with the other's ROM. The machines light both drive lights and fill their
screens with garbage characters (many of which are flashing). I even
tried swapping BOTH the boot ROMs and the character generator ROMs
together, in case they depend on one another, but got the same symptoms.
So the ROMs aren't even compatible between machines.
I looked at the other chips in the vicinity of the ROMs, and all part
numbers matched. And there are no obvious differences between the
motherboards except for that wired-up chip I mentioned in the II.
Very odd.
Obviously I didn't follow all of the traces on the motherboards to see if
they matched. :)
Anyway, the only other thing I could try is to make drive B in the 2 think
that it's drive A, to see if I can boot from there. Does anyone know how
these drives decide which one's A and which one is B? And can I switch
their identities without removing the drives from the metal housing? I
don't have the proper screwdriver to remove the drives.
Doug Spence
ds_spenc(a)alcor.concordia.ca
1:15 p.m.
New subject: Kaypro: 81-149C vs. 81-232
On Sun, 22 Mar 1998, Doug Spence wrote:
Well, I've repeated what I did the other night. I plugged the Kaypro II
into the Kaypro 2's drives, and vice versa. Just the ribbon cable, not
the power. Whichever machine was plugged into the Kaypro II's drives was
able to boot, the machine plugged into the 2's drives just sits there with
the bootup message and eventually beeps and says "I cannot read your disk"
(or similar).
Interesting! Take a look at the back side of the II's drives and see if
you can identify the small black 'cable' that leads to the head. It will
move as the heads move. Anyway, if you spot two, then the machine has
double sided drives and that could be the reason that the 2's drives -
single sided - cannot read the disk.
I tried swapping the II's 81-149C with the 2's
81-232. Neither will work
with the other's ROM. The machines light both drive lights and fill their
screens with garbage characters (many of which are flashing). I even
tried swapping BOTH the boot ROMs and the character generator ROMs
together, in case they depend on one another, but got the same symptoms.
So the ROMs aren't even compatible between machines.
I looked at the other chips in the vicinity of the ROMs, and all part
numbers matched. And there are no obvious differences between the
motherboards except for that wired-up chip I mentioned in the II.
Very odd.
Obviously I didn't follow all of the traces on the motherboards to see if
they matched. :)
If you compare the part numbers on the motherboards - assuming that they
are there - you will find that the board on the II is an 81-110, whereas
the 2 should be either 81-184 or 240. They are not the same board.
Anyway, the only other thing I could try is to make
drive B in the 2 think
that it's drive A, to see if I can boot from there. Does anyone know how
these drives decide which one's A and which one is B? And can I switch
their identities without removing the drives from the metal housing? I
don't have the proper screwdriver to remove the drives.
This is usually set by a socketed DIP jumper plug on the drive circuit
board located near the ribbon cable connector. It could be a DIP switch,
but not usually. If the DIP jumper plug and they are both in the same
position, just swap them. If they are in different positions, then swap
the positions on both drives. These DIP jumper plugs have a frangible
strap between opposing pins, and usually all but one or two are broken.
- don
Doug Spence
ds_spenc(a)alcor.concordia.ca
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
visit the "Unofficial" CP/M Weg site at http://cdl.uta.edu/cpm
with Mirror at http://www.mathcs.emory.edu/~cfs/cpm
11:37 p.m.
New subject: Kaypro: 81-149C vs. 81-232
On Sun, 22 Mar 1998, Don Maslin wrote:
All I can see through the back is what looks like a blue 16-pin DIP chip
in a socket labeled "2F" in drive B and not drive A. This is probably the
jumper plug you're talking about. I can't see the top surface, so I can't
see if there are straps, broken or otherwise. I could probably remove the
thing from drive B, but inserting it into the other drive would be
impossible without removing the drive from the metal housing.
Of course, if I simply removed the part from drive B, and connected the
ribbon cable to B and not to A, it might work. I'd rather not have
another loose part to keep track of until I get the right tool to
reinstall the thing, though. :/
Doug Spence
ds_spenc(a)alcor.concordia.ca
Interesting! Take a look at the back side of the
II's drives and see if
you can identify the small black 'cable' that leads to the head. It will
move as the heads move. Anyway, if you spot two, then the machine has
double sided drives and that could be the reason that the 2's drives -
single sided - cannot read the disk.
Both machines have single-sided drives, and the disk I have is definitely
single-sided.
If you compare the part numbers on the motherboards -
assuming that they
are there - you will find that the board on the II is an 81-110, whereas
the 2 should be either 81-184 or 240. They are not the same board.
The 2 has an 81-240A. I can't find a number on the II's motherboard.
Anyway, the
only other thing I could try is to make drive B in the 2 think
that it's drive A, to see if I can boot from there. Does anyone know how
these drives decide which one's A and which one is B? And can I switch
their identities without removing the drives from the metal housing? I
don't have the proper screwdriver to remove the drives.
This is usually set by a socketed DIP jumper plug on the drive circuit
board located near the ribbon cable connector. It could be a DIP switch,
but not usually. If the DIP jumper plug and they are both in the same
position, just swap them. If they are in different positions, then swap
the positions on both drives. These DIP jumper plugs have a frangible
strap between opposing pins, and usually all but one or two are broken.
12:46 p.m.
New subject: Kaypro: 81-149C vs. 81-232
On Sun, 22 Mar 1998, Doug Spence wrote:
Humm... so I've been working from bad assumptions all along. They don't
use the same boot ROM. However, as I mentioned, the Kaypro 2 did boot
from this disk when attached to the II's drives instead of its own.
Is it possible the drives themselves have different specs that might
interfere as well?
Not to my knowledge.
<sigh>
Yup. I do have a couple of missing keycaps with good plungers, but
generally I'm looking at what you describe.
I really wish people would treat old hardware better in the Salvation Army
stores. That's where I got both of these machines (at different times),
and from previous observations, that's where I'd guess the damage
occurred.
OK. Considering the differing boot ROMs, though, it's possible that the
only repairs that will need doing will be to the keyboards. I'd rather
save BOTH machines than cannibalize one of them.
I'm hoping the plungers are still made and easily available. Or
salvagable off of something of lesser value, like old PC keyboards.
When you can determine the keycaps and switches that you need, send me
private e-mail. We can probably arrive at some arrangement so that I can
supply them to you.
- don
Note: I've changed the subject line to the appropriate chip labels. My
error when posting originally.
On Sat, 21 Mar 1998, Don Maslin wrote:
Sorry about that, the chip in location U47 was "81-149C", not what I
wrote above. I guess I made the error because of the orientation of the
machines - they were connected to each others' drives and thus reversed
front-to-back, and I ran out to the other room to read the labels while in
the middle of the post. I must've read the chip location off one board,
then scanned directly across to the chip on the other board, without
taking into account the reversed orientation. :(
Do you (or anyone else) know if it's a known modification? What I mean
is, does anyone know why this chip might be wired up this way? Does it
solve some known problem with the Kaypro II, or make an enhancement?
There were a couple of common mods that were made to K-IIs - the first
more frequently than the second. The first bumped up the processor speed
The
Kaypro II has a chip with a sticker marked "81-146A", with the "A"
stamped on in read ink. The Kaypro 2 has a chip with "81-232" on it, in
the same location.
If the layout of the two boards seem identical, the chip in the II marked
"81-146A", which is the character generator ROM, is in the wrong location
(U47). It should be in U43. The one in U47 should be either "81-149" or
"81-232". They may have gotten swapped. The chips
at position U87 on both motherboards are marked DM74LS390N, but
the one in the Kaypro II has been messed with. It's a 16-pin chip, and
pin 1 has been bent upward and a wire soldered onto it, which leads to pin
6. Pin 9 is missing. Pins 12 and 15 are attached with a wire.
Is this normal for a Kaypro II, or has someone made a modification?
It is a modification. from 2.5mHz to 4. The second was rather more involved
and upgraded the
machine to double sided drives. I have not been involved with
either, so
I cannot do much more than relate that information. You might want to
check the TCJ website and see if they have any information there.
Anyway, I managed to make a copy of the WordStar disk
that came in the
drive of the II today, using my Amiga 1000, A1060 SideCar, A1020 5.25"
floppy drive, and TeleDisk. So now I have a disk that boots reliably
instead of 1 out of every 5-10 times. That meant that I now know there's
something wrong with the Kaypro 2, because it won't boot at all with the
new disk. Before, it may have just been a borderline disk that was
causing the problem.
Not necessarily. Unless both machines used the 81-232 boot ROM, there is
every chance that they both will not boot from the same bootable disk.
The boot ROM determines the revision of the operating system required. So (tell me if this was a bad/dangerous thing to do) I
opened both
machines up and attached them to each others' disk drives. They were
plugged into a power bar, so I powered them up simultaneously with that.
The Kaypro 2 boot up with no problems, using the II's drives, and the II
was incapable of booting using the 2's drives, so I've got the problem
located to drive A of the Kaypro 2 now.
Maybe not. See above. And BTW,
both the II and the 2 have full-height drives.
Both keyboards have missing keys (including broken plungers). Will this
be easy to fix?
The usual failure mode is for the cruciform projection on the switch
plunger to get broken off. You will need to unsolder the switch and
replace it with a good one. With the benefit of a solder sucker, it is
not necessary to remove the circuit board from the keyboard metal work.
OK. I've had the keyboards open and it doesn't look like an easy job,
though. :/ Looks like time to review Tony's (un)soldering techniques. :)
I'm
thinking of fixing the 2, and using the II for parts, simply because I
like the colour of the 2's green phosphor monitor better (and some other
minor things). :) Is one model more rare than the other? IOW, does one
warrant saving more than the other? If not, I'll go with my feeling and
fix the 2 with parts from the II.
The 2 is probably less common. Thanks for the info, Don!
Doug Spence
ds_spenc(a)alcor.concordia.ca
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
visit the "Unofficial" CP/M Weg site at http://cdl.uta.edu/cpm
with Mirror at http://www.mathcs.emory.edu/~cfs/cpm
10:58 p.m.
New subject: Kaypro: 81-149C vs. 81-232
On Sun, 22 Mar 1998, Don Maslin wrote:
OK, thanks. It's an easy job figuring out which ones I need, assuming
that the keys with no obvious damage still work.
There were a couple of common mods that were made to
K-IIs - the first
more frequently than the second. The first bumped up the processor speed
from 2.5mHz to 4. The second was rather more involved and upgraded the
machine to double sided drives. I have not been involved with either, so
I cannot do much more than relate that information. You might want to
check the TCJ website and see if they have any information there.
I visited, but didn't look too hard. I see that one can buy drives and
other parts for the Kaypro through the TCJ website, though.
The numbers on all of the oscillators match, between the two machines,
though I suppose that isn't a definitive way of telling if a machine has
been accelerated or not. Especially considering the possibility that BOTH
of them could have had this done to them. :)
Niether the II nor the 2 has double-sided drives, BTW.
I'm hoping
the plungers are still made and easily available. Or
salvagable off of something of lesser value, like old PC keyboards.
When you can determine the keycaps and switches that you need, send me
private e-mail. We can probably arrive at some arrangement so that I can
supply them to you. - don
Doug Spence
ds_spenc(a)alcor.concordia.ca
9619
days inactive
9621
days old
8 comments
3 participants
participants (3)
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