28 Sep
2006
28 Sep
'06
8:50 p.m.
Still can't find manuals. But here's what I know and maybe people can fill
in the blanks.
First info - Base model is 45711E, supposedly that designates 110+, 512k
ram, & modem. The memory drawer has a model 82981A, which googling suggests
is 128k ram addon. There's a metal shield over the chips and I don't have
the right torq bit to remove. Upon boot all the ROM ID shows BBBBBB.
First question - going into system config lets me set the memory split
between main memory and edisk. All choices add up to 896k. How does that
square with 128k + 512k?
Second info - The PAM menu shows the following application choices - DOS
CMDS, HP reflection, VT reflection, Memo Maker, Time Management, and BASIC.
However, opening up the software drawer shows the following chips in the
following locations 82863K-Reflection1 (0L), 45504K-MemoMaker/TimeMgt (1L),
82862K-BASIC (4L), 45555K-1/2-ExecutiveCardMgr (5H),
45555K-2/2-ExecutiveCardMgr (5L), 45548K-1/2-Lotus123 (6H),
45548K-2/2-Lotus123 (6L).
Second question - I assume the PAM menu selections for HP reflection and VT
reflection are handled by the single 82863K rom. I am curious why the
Executive Card Manager and Lotus123 don't show up in the PAM menu?
Misc. questions - The built in battery is obviously dead and won't hold a
charge, as the unit won't run at all without the AC adapter. Every time I
boot up though, it asks to reformat the A drive due to memory loss. More
importantly, it has lost the date/time and system config settings
(memory/edisk split for example). I'm curious if the date/time and config
settings are kept by a different battery I may need to replace, or if all of
the above is maintained by the single battery. I will have to hunt up a new
battery.
This 110+ is a really nice box! I'm quite fascinated by the built-into-rom
HP terminal emulator (dumb terminal emulation won't do) as well as VT
terminal emulator and serial port, all in a small package! Sweet!
Thanks for any pointers!
Jay West
29 Sep
29 Sep
2:23 a.m.
Jay West wrote:
First question - going into system config lets me set
the memory split
between main memory and edisk. All choices add up to 896k. How does
that square with 128k + 512k?
It doesn't. I suspect your RAM drawer has more than 128KB.
Second info - The PAM menu shows the following
application choices -
DOS CMDS, HP reflection, VT reflection, Memo Maker, Time Management,
and BASIC. However, opening up the software drawer shows the following
chips in the following locations 82863K-Reflection1 (0L),
45504K-MemoMaker/TimeMgt (1L), 82862K-BASIC (4L),
45555K-1/2-ExecutiveCardMgr (5H), 45555K-2/2-ExecutiveCardMgr (5L),
45548K-1/2-Lotus123 (6H), 45548K-2/2-Lotus123 (6L).
Second question - I assume the PAM menu selections for HP reflection
and VT reflection are handled by the single 82863K rom. I am curious
why the Executive Card Manager and Lotus123 don't show up in the PAM
menu?
It's all very weird. The ROMs are a mix of boot code, ROM disc data
that gets merged into the B: drive, and executable code.
I believe mine is similarly configured to yours. I have PAM menu
selections for DOS Commands, MemoMaker, Time Managemt, HP Reflection,
VT Reflection, Basic, and 123 Rel. 2.01. If I look at B: with "dir b:"
I see:
Volume in drive B has no label
Directory of B:\
BIN <DIR>
WSS <DIR> 3-05-92 10:09a
MEMO-TM <DIR> 1-23-86 12:02p
HP82863K <DIR> 11-01-85 10:03a
BASIC32K <DIR> 3-18-85 12:00p
RFN <DIR> 1-29-92 3:06p
45539K <DIR> 5-05-87 3:07p
HELP <DIR> 5-06-87 11:07a
8 File(s) 2097152 bytes free
BIN is from the Portable Plus ROM. MEMO-TM is MemoMaker and Time
Management. HP82863K is Reflection. BASIC32K is BASIC. 45539K is
1-2-3 and HELP is 1-2-3's help file.
WSS and RFN are, I believe, HP-internal applications. Some of the
programs in RFN claim to be "Remote FIREMAN", and I remember FIREMAN
being a thing that the HP CEs used to dial into in the 1980s to log
completion of a service call.
Directories that want to present stuff in PAM have a PAM.MNU file
that instruct PAM.
Misc. questions - The built in battery is obviously
dead and won't
hold a charge, as the unit won't run at all without the AC
adapter. Every time I boot up though, it asks to reformat the A drive
due to memory loss. More importantly, it has lost the date/time and
system config settings (memory/edisk split for example). I'm curious
if the date/time and config settings are kept by a different battery I
may need to replace, or if all of the above is maintained by the
single battery. I will have to hunt up a new battery.
No, there is only the one battery. What do you mean by "boot up"?
If you're unplugging it and the battery is dead, yeah, it's probably
losing RAM. I'm thinking that if you leave it plugged in you should
be able to turn it off and back on.
There are several ways to reset the Portable Plus. Shift+CTRL+Break
is supposed to reboot from A: (i.e. read CONFIG.SYS from the RAM disk).
Shift+CTRL+Extend char+Break is supposed to reboot from B: (i.e.
ignore the CONFIG.SYS on the RAM disk). If these don't work,
holding down the contrast key (the half-light half-dark circle to the
right of the right shift key) will reset and reboot from A:.
If none of these work, you can pull the battery cover off and push
a little button there, but that's The Reset Button and will wipe your
RAM disk too.
None of these are the same as turning it off (by pressing f8 in PAM)
and turning it back on (by pressing a key on the keyboard). These are
really more like putting it to sleep and waking it up.
This 110+ is a really nice box! I'm quite
fascinated by the
built-into-rom HP terminal emulator (dumb terminal emulation won't do)
as well as VT terminal emulator and serial port, all in a small
package! Sweet!
And with a good battery and a full charge, it will keep up with your
typing all day.
-Frank McConnell
3:46 a.m.
New subject: AMBRA 486 - How To Access BIOS
Hi.
I have an Ambra Sprinta, circa 1991-1992, running MS-DOS 6.
I don't know how to access the BIOS. I've tried several key
combinations, even held down as many keys as possible during boot-up,
but nothing's worked.
When the machine is turned on, there's first a screen with "AMBRA" at
the top and three check-marks appearing down a list during a short
diagnostic, then that screen goes away and DOS text is visible during
the rest of the boot-up. Pressing any keys at all, during this whole
process, only gets the machine beeping.
Thanks in advance for help finding the correct key combinations.
Greg P.
4:31 a.m.
New subject: AMBRA 486 - How To Access BIOS
after the usual delete or function keys i try shift-ctrl-alt-delete .
this works with some bios's alternately take some ram out. that
usually forces the bios into setup as the detected amount of ram has
changed.
On 29 Sep 2006, at 08:46, Greg Purvis wrote:
Hi.
I have an Ambra Sprinta, circa 1991-1992, running MS-DOS 6.
I don't know how to access the BIOS. I've tried several key
combinations, even held down as many keys as possible during boot-up,
but nothing's worked.
When the machine is turned on, there's first a screen with "AMBRA" at
the top and three check-marks appearing down a list during a short
diagnostic, then that screen goes away and DOS text is visible during
the rest of the boot-up. Pressing any keys at all, during this whole
process, only gets the machine beeping.
Thanks in advance for help finding the correct key combinations.
Greg P.
12:08 p.m.
New subject: AMBRA 486 - How To Access BIOS
Hi.
I have an Ambra Sprinta, circa 1991-1992, running MS-DOS 6.
I don't know how to access the BIOS. I've tried several key
combinations, even held down as many keys as possible during
boot-up, but nothing's worked.
When the machine is turned on, there's first a screen with
"AMBRA" at the top and three check-marks appearing down a
list during a short diagnostic, then that screen goes away
and DOS text is visible during the rest of the boot-up.
Pressing any keys at all, during this whole process, only
gets the machine beeping.
Try F2, that worked for an "Blue Lightning" Ambra I had knocking about a few
years back, but you have to press it as soon as you turn it on, that had me
going in circles for a bit.
Dave ;)
16 Oct
16 Oct
12:03 a.m.
New subject: AMBRA 486 - How To Access BIOS (Follow-up)
I found out that CTL-ALT-S is pressed during boot-up, to access the
Ambra Sprinta's setup page.
29 Sep
29 Sep
3:54 a.m.
New subject: AMBRA 486 - Installing a CD-ROM
Hi
Has anyone successfully installed a CD-ROM in an Ambra computer circa
1991-1992?
At first I was going to try to swap one of the floppy drives for the
CD-ROM but I've learned that the ROM drive needs different cables,
probably some sort of special adaptor.
The computer has MS-DOS 6.0 loaded and I've been advised to learn LINUX
instead, because it would make any jobs I'm doing a lot easier. In the
meantime, I'm hoping I can collect a few more clues about doing this
with the current OS.
Thanks in advance for any ideas about how to do the installation.
Greg P.
6:17 p.m.
Still can't find manuals. But here's what I know and maybe people can fill
in the blanks.
First info - Base model is 45711E, supposedly that designates 110+, 512k
Yep.
ram, & modem. The memory drawer has a model
82981A, which googling suggests
is 128k ram addon. There's a metal shield over the chips and I don't have
the right torq bit to remove. Upon boot all the ROM ID shows BBBBBB.
IIRC, the RAM drawer has 128K on the mainboard, but you can add 1 or 2
daughterboards, each is another 128K. All that RAM, BTW is in 8K*8 SRAM
chips (6264 type things). The original 110 had pin-through-hole (a large
board the entire size of the machine was almost all 6264s!), the 110+
used SMD ones.
You'll need (at least) TX6, TX8 and TX10 Torx tools and a set of metric
nutrdirvers to take this toy apart.
First question - going into system config lets me set the memory split
between main memory and edisk. All choices add up to 896k. How does that
square with 128k + 512k?
Sounds likle you have a couple of dughterboards fitted :-)
Second info - The PAM menu shows the following application choices - DOS
CMDS, HP reflection, VT reflection, Memo Maker, Time Management, and BASIC.
However, opening up the software drawer shows the following chips in the
following locations 82863K-Reflection1 (0L), 45504K-MemoMaker/TimeMgt (1L),
82862K-BASIC (4L), 45555K-1/2-ExecutiveCardMgr (5H),
45555K-2/2-ExecutiveCardMgr (5L), 45548K-1/2-Lotus123 (6H),
45548K-2/2-Lotus123 (6L).
Second question - I assume the PAM menu selections for HP reflection and VT
reflection are handled by the single 82863K rom. I am curious why the
Executive Card Manager and Lotus123 don't show up in the PAM menu?
The ROMs contains something a bit like an MS-DOS filesystem, you can have
several applicaitons in one ROM (this would (normally?) be done by having
subdirectories in the ROM). The TechRef gives the format of the data for
the ROMs, I may even have software (runs on the 110+) to create them.
For an application (in ROM or on disk) to show up in PAM, there needs to
be some data file which defines the label to appear in PAM, the
executable filename, and so on. The format of that (IIRC it's a text
file) is also documented. I would assume some of your ROMs don't contain
said file.
I assume you've got an MS-DOS prompt by now. Try DIR B: and see what
shows up.
Misc. questions - The built in battery is obviously dead and won't hold a
charge, as the unit won't run at all without the AC adapter. Every time I
boot up though, it asks to reformat the A drive due to memory loss. More
importantly, it has lost the date/time and system config settings
(memory/edisk split for example). I'm curious if the date/time and config
settings are kept by a different battery I may need to replace, or if all of
the above is maintained by the single battery. I will have to hunt up a new
battery.
No, there's only one battery, the 6V lead acid one.
Now getting that out is 'interesting'. The official HP procedure involves
bending some contact straps, they tend to break off. In fact HP tell you
to replace them every time, but good luck in finding them.
I have a sort-of workaround. It takes longer, but you don't bend
anything. It goes like this :
Remove the clip on battery cover [1] at the back. Move the jumper link to
the 'off' postion. Remove both drawers
Remove the (black) plastic cover over the battery terminals (2 screws).
Undo the terminal nuts behind it _but don't bend the straps down_. Loosen
the nuts holding the straps to the PCB. HP suggest you do this with the
machine upside down so that any swarf falls away from the PCB.
Now remveo all the screws on the bottom that hold the case together (I
forget if some are under labels/feet). Put the machine the right way up,
hold the straps away from the battery terminals (if the nuts on the PCB
are loose enough, you don't have to bend the straps to do this), and lift
up the top case starting at the rear. Free the connector panel from the
top case, then reach inside and unplug the display and keyboard cables
from the main PCB.
Turn the top case over. Remove the 4 Torx screws that go throught the
posts for the display hinges. One of the grounding flexiprints is now
free IIRC. Put the top case the right way up, lift off the centre
section betweem the display hinges (I forget whether the display needs to
be open or closed, but it's obviosu when you do it). Then take out the
battery and the foam pad around it.
[1] If you are really lucky, that cover will be held on by 2 screws and
will have a connector on it. That's the connector for the _rare_ video
display adapter which displays the LCD contents on a composite monitor.
If you have this connector, take out the 2 screws, ease away the cover,
unplug the end of the cable from the main PCB and later free the ground
tab when you remov the battery terminals, etc.
-tony
7:20 p.m.
Tony wrote....
IIRC, the RAM drawer has 128K on the mainboard, but
you can add 1 or 2
daughterboards, each is another 128K.
Ok, I got the right torx tools, and took the
cover off the memory drawer.
There is a large "base" card in the bottom of it, and two daughtercards that
appear to fill the entire case. That sounds like 384k total in the RAM
drawer. That must mean 512k is built into the base unit without the memory
drawer? Ok.... but I could have sworn I saw somewhere that the 110+ could go
to 1mb. Wonder where the additional 128k goes?
For an application (in ROM or on disk) to show up in
PAM, there needs to
be some data file which defines the label to appear in PAM, the
executable filename, and so on. The format of that (IIRC it's a text
file) is also documented. I would assume some of your ROMs don't contain
said file.
Interesting info, but I'm not interested in the rom format (yet).
I'm much
more concerned why neither executive card manager and lotus 123 don't show
up in pam. They don't show up in the directory of the B drive either - and I
am relatively sure from other research that they ARE supposed to show up
there when installed.
On thing I'm curious about is the jumpers inside the software drawer. Any
docs on those? It may be coincidence, but all the jumpers (one for each H/L
set) are in the same position for each of the six slots - and the two roms
that don't appear are the only two roms that use both H and L sockets. So
this makes me wonder if they were plugged in but the jumpers just never set
right. Anyone have docs on just how those jumpers are supposed to be set?
I assume you've got an MS-DOS prompt by now. Try
DIR B: and see what
shows up.
Everything that should, except the two app roms mentioned above.
No, there's only one battery, the 6V lead acid
one.
Ok, then the first order of business is to seek out a replacement battery if
one can be found!
I have a sort-of workaround. It takes longer, but you
don't bend
anything. It goes like this :
Thanks a ton, I will look in to your procedure
tomorrow!
Thanks to all for the assistance!
Jay West
30 Sep
30 Sep
6:49 p.m.
Tony wrote....
That sounds right.
IIRC, the RAM drawer has 128K on the mainboard,
but you can add 1 or 2
daughterboards, each is another 128K.
Ok, I got the right torx tools, and took the
cover off the memory drawer.
There is a large "base" card in the bottom of it, and two daughtercards that
appear to fill the entire case. That sounds like 384k total in the RAM drawer. That must mean 512k is built into the base
unit without the memory
Again, that sounds right. Yours is a -E model, isn't it? That has 512K
buit-in (I _think_ it's 256K on the main memory PCB, and 2 more
daughterboards (which are the same as those in the RAM drawer).
Incidnetally, the service mnaual regards SMD stuff as not being
field-repairable (No idea what the problem is!), and doesn't include
schematics of the RAM drwaer or daughterboards. They _are_ included in
the technical manaul.
drawer? Ok.... but I could have sworn I saw somewhere
that the 110+ could go
to 1mb. Wonder where the additional 128k goes?
You don't _have_ to have a RAM drawer and a software (ROM) drawer. I
think you cna have 2 RAM drawers. There as also a 1M RAM drawer made, I
believe it was bank-switched, and I have no details or schematics for it.
I've never seen one.
[...]
Interesting info, but I'm not interested in the
rom format (yet). I'm much
more concerned why neither executive card manager and lotus 123 don't show
up in pam. They don't show up in the directory of the B drive either - and I
am relatively sure from other research that they ARE supposed to show up
there when installed.
They certainly should show up in the B: drive directory. Maybe defective
ROMs? Start by removing and replacing them..
On thing I'm curious about is the jumpers inside the software drawer. Any
docs on those? It may be coincidence, but all the jumpers (one for each H/L
set) are in the same position for each of the six slots - and the two roms
that don't appear are the only two roms that use both H and L sockets. So
this makes me wonder if they were plugged in but the jumpers just never set
right. Anyone have docs on just how those jumpers are supposed to be set?
From memory....
This machine has an 80C86 (not 80C88) processor, it has a full 16 bit
databus, therefore. The H and L sockets are the high and low byte of the
databus (the ROMs, as usual, being 8 bits wide).
There are basically 2 types of ROM format. Either for 8 bits wide in a
single ROM chip which can go in any socket, or 16 bits wide, in a pair of
ROMs, which have to go in n H and L pair of sockets, and the right way
round. The advantage of the latter type is that you can execute programs
directly from the ROM without having to copy them into RAM first, this is
useful with big programs and limited RAM.
I can't rememebr what all the jumpers do, but it's not really one per
pair of sockets. I do remember one of the functions, though. The sockets
can take up to 128K byte devices, but the largest _EPROM_ you could use
was a 32K byte one, larger ROMs had to be mask-programmed. It's possible,
but settign the jumpers correctly, to take over 4 sets of sockets to take
EPROMs and appear as a single 128K chip. The idea of that was if you
wanted to produce a 128K byte ROM, you could test your code in EPROMs
before having the <n> thousand mask-programmed chips made.
However, one company (not HP) had a much better solution. They made up
little carrier boards that fitted into the 28 pin sockets on the 110+,
and which had a 32 pin PLCC EPROM (either windowed or OTP) soldered to
it. At one end of the board was a 5 pin header. In normal use you put
jumpers on pins 1-2 and 4-5, the thing then appeared as a 128K masked
ROM. To program it, you used a special modifed programmer (it was
something called a ROMBO IIRC), that had a cable that connected to the
header to provided VPP, the programming pulse, etc.
I have one of the programmers on extended loan from HPCC (it's more use
in my workshop than in another member's loft), I also have a couple of
the EPROM modules. Sometime I should trace out the connections, etc.
If you really want me to, I can work out the functions of the jumpers
from the manual. Personally, I've never needed to
change the ones in my
machine.
I assume you've got an MS-DOS prompt by now.
Try DIR B: and see what
shows up.
Everything that should, except the two app roms mentioned above. No, there's only one battery, the 6V lead
acid one.
Ok, then the first order of business is to seek out a replacement battery
if
one can be found! from the original battery, but it can be done. My 110+
and 110 (which
uses a slightly different battery) have that arrangement.
-tony
7:20 p.m.
On Saturday 30 September 2006 06:49 pm, Tony Duell wrote:
3 off 2.5Ah Cyclon cells will fit perfectly. You'll have to solder up
straps to link them together, and solder then to the terminal board taken
from the original battery, but it can be done. My 110+ and 110 (which
uses a slightly different battery) have that arrangement.
If that's what you can get, yeah, but there are 3- and 6-cell arrangements
of those also commonly available as well.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
No, there's only one battery, the 6V lead acid
one.
Ok, then the first order of business is to seek out a replacement battery
if one can be found!
8:38 p.m.
> On thing I'm curious about is the jumpers
inside the software drawer. Any
> docs on those? It may be coincidence, but all the jumpers (one for each H/L
Extracted from the Technical Reference Manual.
Small group (sockets 0 and 1)
XW1
Banks 0 and 1 : Independant ROM pairs -- A
Independant EPROM pairs -- B
Large group (sockets 4, 5, 6, 7)
XW2 XW3 XW4 XW5 XW6
Banks 4,5,6,7 : Independant ROM pairs -- A A A A A
Banks 4,5,6,7 : Independant EPROM pairs -- B - B B B
Bank 7 : Up to 4 cascaded pairs of 32K ROM A B B B B
Bank 7 : Up to 4 cascaded pairs of 32K EPROM B B B B B
Where '-' means don't care.
The cascaded modes let you use 4 pairs f sockets to emulate a 128K ROM.
They are fitted in order 5 6 7 4 (not the obvious one!), and appear as
bank 7. Banks 4,5,6 do not exist in this mode.
The factoru configuration is to have all jumpers in position A, that is
for indepenadnnt ROMs in all banks.
-tony
29 Sep
29 Sep
11:26 p.m.
Went to storage to paw through some more 110 and Portable Plus
bits and came up with another tidbit from the manual for the 82984A
128K Memory Card (p/n 82984-90004).
Turn the Portable Plus off with PAM f8. Press and hold Extend char
and Shift, then press and hold f8 for at least five seconds. When you
let go it will start up with a diagnostic menu. Note that the
Software/Memory Drawer test on Shift-f2 takes five minutes per 128KB
RAM, but it will tell you what sockets it thinks have ROMs in.
-Frank McConnell
30 Sep
30 Sep
6:39 p.m.
Frank wrote....
Turn the Portable Plus off with PAM f8. Press and
hold Extend char
and Shift, then press and hold f8 for at least five seconds. When you
let go it will start up with a diagnostic menu.
That's awesome info Frank, thanks! The diagnostic shows two bad roms, and
they happen to be the only two high order roms of the only two rom sets in
the machine (lotus & executive card manager).
Are the rom blanks a common chip? Anyone have images I can download and burn
(or chips I can borrow & copy)?
I just love the Reflection1 terminal emulation. Someday I may have to dig
into the rom format. I was thinking (depending on the size of the roms) that
perhaps I could write a snippet of code that emulates the terminal side of
the HP 264x bootloader rom, so my 21MX's can boot from the 110 :D
Jay West
29 Sep
29 Sep
2:06 p.m.
Frank wrote....
Dp you have any other ROMs in the 'H' sockets? If not, it's possible you
have a bad buffer chip or something.
Turn the Portable Plus off with PAM f8. Press
and hold Extend char
and Shift, then press and hold f8 for at least five seconds. When you
let go it will start up with a diagnostic menu.
That's awesome info Frank, thanks! The diagnostic shows two bad roms, and
they happen to be the only two high order roms of the only two rom sets in
the machine (lotus & executive card manager).
Are the rom blanks a common chip? Anyone have images I can download and burn
See my other message. Those are almost certainly 128K ROMs, and there is
no standard EPROM equivalent. I have seen the modules on E-bay _once_,
but they are not common.
(or chips I can borrow & copy)?
I just love the Reflection1 terminal emulation. Someday I may have to dig
into the rom format. I was thinking (depending on the size of the roms) that
It is docuemnted!. Let me know if/when you want me to type it up from the
technical manual...
-tony
1 Oct
1 Oct
4:17 p.m.
Tony wrote....
> Do you have any other ROMs in the 'H'
sockets? If not, it's possible you
> have a bad buffer chip or something.
I do, but it is only the two rom sets that
use the H sockets that are not
appearing in the PAM list. The roms that do appear, are only using the low
sockets. I think that's not a coincidence.
Specifically U5 (74HC245) on the ROM drawer PCB.
Octal Bus Transceiver... I guess there are two of them, one for the lower 8
and the one at U5 must be for the upper 8? I am not familiar with that chip.
Is there a relatively easy way to test it before just replacing it?
Unrelated: I wanted to try the H/L pair chips in a different socket. I chose
to remove the BASIC chip and try that one. Upon removal, I noticed the BASIC
chip had a bent pin. I figured whoever put it in must not have paid close
attention. I put a H/L set (Lotus) in there to check it, and noticed that it
bent the same pin on the L chip of the Lotus set. Argh! So I removed the
chip and under inspection under a magnifier, I can see that the
corresponding hole in the boards "socket" was fouled with something, causing
any chip put in there to get that pin pushed up and bent. Yikes. Very
careful work under the magnifier cleared the obstruction. I straightened the
pin on the BASIC chip and put it back in and it went in fine (and works
fine). However, soon as I touched the pin on the L Lotus chip, it broke off
(right where the pin becomes narrow). So, I get to try and carefully
reattach that pin leg to the chip. Can anyone share broken chip leg repair
techniques? I can't attach a tiny segment of wire as a brace - the "socket"
on the board is the type where each pin gets it's own socket so a thicker
leg probably won't go in.
Jay West
4:25 p.m.
On Sunday 01 October 2006 04:17 pm, Jay West wrote:
Unrelated: I wanted to try the H/L pair chips in a
different socket. I
chose to remove the BASIC chip and try that one. Upon removal, I noticed
the BASIC chip had a bent pin. I figured whoever put it in must not have
paid close attention. I put a H/L set (Lotus) in there to check it, and
noticed that it bent the same pin on the L chip of the Lotus set. Argh! So
I removed the chip and under inspection under a magnifier, I can see that
the corresponding hole in the boards "socket" was fouled with something,
causing any chip put in there to get that pin pushed up and bent. Yikes.
Very careful work under the magnifier cleared the obstruction. I
straightened the pin on the BASIC chip and put it back in and it went in
fine (and works fine). However, soon as I touched the pin on the L Lotus
chip, it broke off (right where the pin becomes narrow). So, I get to try
and carefully reattach that pin leg to the chip. Can anyone share broken
chip leg repair techniques? I can't attach a tiny segment of wire as a
brace - the "socket" on the board is the type where each pin gets it's own
socket so a thicker leg probably won't go in.
Best thing I can think to suggest there is that you get a socket to plug into
the socket, one where the pins coming out the bottom will go into the
original socekt and where the holes in the top will accomodate whatever you
have to do to get that chip pin repaired...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
5:58 p.m.
Tony wrote....
Try moving one of the single ROMs into an 'H' socket. Does it still
appear (and work correctly)? Single ROMs can go in any socket, H or L, if
the machine is working right.
> Do you have any other ROMs in the 'H'
sockets? If not, it's possible you
> have a bad buffer chip or something.
I do, but it is only the two rom sets
that use the H sockets that are not
appearing in the PAM list. The roms that do appear, are only using the low
sockets. I think that's not a coincidence. Specifically U5 (74HC245) on the ROM drawer PCB.
Octal Bus Transceiver... I guess there are two of them, one for the lower 8
from the LCD module, which was bought-in, not made by
HP).
and the one at U5 must be for the upper 8? I am not
familiar with that chip.
Is there a relatively easy way to test it before just replacing it?
It's not going to be easy to test in-circuit. If you desolder it, it
should be quite easy to check (grab the data sheet, note that pin 19 must
be low to eneable the chip, pin 1 determines which side is input and
which is output, and then whatever you apply to the 'input' side should
appear on the output side). But if you desolder it, you might as well fit
a socket and a new one.
[...]
(right where the pin becomes narrow). So, I get to try
and carefully
reattach that pin leg to the chip. Can anyone share broken chip leg repair
techniques? I can't attach a tiny segment of wire as a brace - the "socket"
on the board is the type where each pin gets it's own socket so a thicker
leg probably won't go in.
What I'd do is find some wire that will go into the sockets on the PCB.
Put the end into the appropratie socket, then fit the chip and carefully
solder the wire to the stub of the pin.
-tony
6470
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6487
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