I spent Newtonsday in a non-traditional manner assembling the Y-drive
mechanism of my HP7245A thermal printer/plotter. The machine now sort-of
works, but the motor driver needs setting up (X drive in particular is
uneven) and there may well be other electronic faults.
I wish I could say it worked first time, but I made 2 silly mistakes. One
was to get the connector missaligned when I plugged the Y motor harness
into the backplane (this caused the PSU to shut down when it tried to run
the Y motor). The other was that after fitting the printhead and trying
to plot something, nothing appeared on the paper. Yes, I'd got the paper
in back-to-front (being thermal, the paper is only sensitive on one side).
Anyway, I'll post my notes on the mechanism below. This is not a
replacement for the HP7245B service manual on hpmusuem.net, it should be
read along with that manual. You need a couple of special tools to
asemble the Y drive, assuming you don't have the offical HP ones (I
wish), I've included insturctions for making them. And I think my way of
setting the motor coupling (needing 3 homemade spacers) is easier than
the HP method.
Feel free to archive this somewhere, make it available, etc. All I ask is
that I am given credit for it.
-tony
PSU Fan Dismantling
-------------------
Dismantle PSU. Disconnect mains input harness from 'line' switch (push-on
terminals). Remove fan and harness from PSU chassis.
Remove cable clip on fan housing. Undo 2 slot-head screws (under label).
Feed cable through housing and remove motor/blade assembly. Recover
thrust pad (inside housing.
Rmmove circlip from end of spindle. Lift off waskers. Remove blade/rotor
>from stator.
Lubricate bearings with light machine oil when reassembling
X Drive Fan Dismantling
-----------------------
Remove fan from X drive chassis (3 screws). Remove adapter from fan (one
further screw).
Remove 4 crosshead screws on fan motor plate. Lift motor assembly out of
housing. Remove 2 slothead screws (under label) and take off plate.
Remove circlip from spindle end WITH CARE, it is spring loaded. Take off
washer, ball race, 'tophat' spacer, spring, second 'tophat' spacer. Lift
out stator and remove second ball race and spacer from spindle.
X Drive Chassis
---------------
Anticlockwise rotation of motor -> Carriage moves to right
To lock motor, apply 5V to one motor winding (e.g. between red and yellow
wires at motor connnector)
Fit to LH side plate :
Microswitch harness (2 microswitches)
Paper roll clip
Y drive clip
Y drive stop (shorter 'tail')
Tensioner assembly
Fit to RH side plate :
Paper roll clip
Y drive clip
Y drive stop (longer 'tail')
Bail spring (loop towards rear of machine)
2 idlers
Motor mounting bracket
Assemble chassis. Fit motor (wires on left side, nuts on front side)
Fit pulley, hole at top. Lock motor (see above).
Fit cable :
LH cable (long end). 3 turns anticlockwise from hole, towards back.
RH cable (short end) : 1+3/4 turns clockwise from hole, towards front.
Y drive special tools
---------------------
1) 3 spacers, Each 30mm long, made from 1/2" brass rod, 3.5mm hole drilled
centrally (along axis). Length is reasonably critical. These are used in
place of the plastic motor mount when using the platten-movement tool and
checking the motor coupling
2) Platten-movement tool. Brass block, 5/8" square by 3" long. Drill
centrally 5mm, and tap M6 (1). Drill 3.5mm holes 1+5/16" either side of
this (approximately 316" from ends of bar). All holes to be aligned along
center of bar, and drilled perpendicualr to the face :
Top View:
Centre Line
|
+----------------------------+ ----
| o * o | 5/8"
+----------------------------+ ----
| | | | |
| | <1+5/16> | <1+5/16> | |
| | | |
| <----------3-------------> |
Mill away ends of bar to reduce thickness to aproximately 1/8" (thickness
of motor flange) for about 1/2"
SIde view:
+------------------------+ ----------
| | 1/2
| |
+-----+ + ----+ ----------
| | 1/8
+ -----------------------------------+ ----------
| | | |
| | | |
|<1/2>| <-------2------------> |<1/2>|
The central hole is fitted with an M6 (1) bolt. Either a stnadard
commercial one, or make a both from 1/4" or 5/16" brass rod, turned down
to 6 mm and threaded with a die for a length of 50 mm. Knurl the 'head'
end to give a suitable grip and part off.
In use, this tool is fitted in place of the stepper motor, using 2 of the
spacers mentioned above. The M6 screw presses on the end of the platten
spindle. With the platten fixing screws hand-tight, the M6 screw is used
to postion the platten to align the LH sprockets.
(1) THis thrad is not critical, although obviously the hole and bolt must
be the same thread. M6 is 1mm pitch. 0BA, or 1/4-28 UNF would be fine too.
3) A courved straightedge. This is fitted round the platten, in contact
with the teeth on the LH sprockt. It is then used to line up those teeth
with the ones on the LH drum sproket.
Turn a brass cylinder 1.27" (32,3mm) diameter by 5/8" thick
(approximately). Drill a 3.5mm hole along the axis, tap M4. Drill a 2.5mm
hole radially, 1/4" from one face, tap M3.
Drill a 4mm hole in a 6" (approx) flat metal square (e.g. 1/8" thick
aluminium), aporximately 1.5" from the edges. Screw the cylinder there
with an M4 screww, radial hole closer to the plate.
The actaul straightedge is made from brass strip, 1/2" wide. Drill a 4mm
hole on the centre line close to one end, fix to the cylinder with an M3
screw and washer. Ensure the strip contacts the plate along its full
length. Bend the strip round the cylinder by hand for about 1/2 turn,
keeping it in contact with the plate. Remove from the cylinder, continue
forming by hand so as to fit closely round it.
Y Drive Assembly
----------------
Assemble the following 6 subassemblies first.
1) Belt cover : Fit the belt spring leaf (2 screws/nuts/washers)
2) Paper clamp : Assemble the tension arms to the side rails, fit the
springs. Assemble the front roller (presses against drum when machine is
asembled), screw side rails to this. Fit the white plastic guide roller
to the tension arms
3) Paper sensor top cover. Assmeble the magnet, metal return plate, 2
spacers to this plate with 2 screws, washers, and nuts.
4) Paper sensors : Fit the U-shaped brackets to the cross rail. The
easiest way to do this is to fit the spring to the cross rail, using a thin
rod (e.g. a small crosspoint or Torx srewdriver inserted through the hole
on the bottom of this rail to giude it in place. Then fit the bracket to
the rail alongside the sping ( top upringht (tapped hole) inside the
rail), pull out the rodn amd use a small screwdriver to compress the
spring a little and slide the bracket in place. Use the rod to align the
spring and the holes in the rail and U-bracket. Fit the special adjusting
screw from the bottom, screw into the tapped hole in the U-bracket. Fit
the reflective optoswitches to the sensor PCBs, fit these to the
U-brackets (PCB away from the bracket), fit the allen-head screws and
tighten (Sensor pin side against the 'bumps' on the U bracket). Fit the
cross rail to the left side plate (cable form under the rail), fit the
fixing screw finger-tight.
5) Platten : Fit an E-circlip into the grouve on the platten spindle (this
is the one with one end turned down). Fit a plain (not flanged) ball race
inside the platten at each end. WIth the platten mounting face away from
you and the flat (prinhead surface) towards the top, slide in the spindle
>from the RHS, fit a samll sprocket on the LH end, fit a clamp and
tighten. Slide the other small sproket onto the RH end of the spindle,
fit the coupling/belt sprocket (pin to go through hole in paper
sprocket), fit clamp. Place assembly on a flat surface and alighn the
pins on the 2 paper sprockets. Tighten the clamp at the RH side. Fit the
mouting rail to the platten with 3 allen screws, finger tight.
6) Drum : Fit an E circlip into the grouve nearest the end of the drum
spindle. Slide a large paper sprocket onto thi from the long end of the
spinddle (clamp end to be towarfs the long end, fit a clamp. Slide the
sprocket hard against the E-clrclip, tighten the clamp. Fit the drum
tube, the metal drum onto the spindle, fit a clamp inside the latter so
that the screw can be accessed via the hole in the metal drum. Fit the
other large sprocket, engaging the pin on the metal drum with its hole.
Alight the teeth on the paper sprokects on a flat surface as before and
tighten the clamp. Fit an E-circlip into the remaing groove on the drum
spindle. Slide a flanged ball race onto each end of the drum spridle,
flanges towards the drum.
Assembling the Y drive : Fit the platten to the left side plate, motor
coupling/sprocket to the right. Fit and tighten 2 screws. Fit the drum
into the left side plate, short end of the spindle to the left. Fit the
right side plate, motor harness loop under the paper sensor cross rail.
Screw in the the 3 screws that hold the the RH side plate in place. Leave
the one in the paper sensor rail finger-tight, note that the top screw on
the platten mouting on this slde is the long one and fitted with a spacer
under the head (to keep the motor harness away from moving parts.
Fit the hase plate under the paper sesnor, the paper senosr harness and
notor harness fit into the slot on the cross rail. Screw to the cross rail
with 1 screws and to the lugs on the side plates with 4 scress and
hexagonal spacers. Tighten the 2 screws holding the sensor cross rail to
the side plates.
Fit the platten movement tool to the stepper motor mouting holes with 2
motor mouting screws and 2 of the spacers made earlier. Slide the platten
all the way to the right and screw in the the bolt on the tool until it
just touches the end of the shaft. Fit the curved straightedge tool round
the platnen, againsts the teeth of the LH paper sprocket. Screw in the
bolt of the movement tool until the straightedge contacts the teeth of
the LH drum sprocket. Tighten the 3 allen screws holding the platten to
the mouting rail (a ball-ended tool is useful here), remvoe the special
tools.
Fit the toothed belt to the platten motor coupling sproket. Fit the
sproket to the drum spindle. Fit the tensioner sleeve to the tensioner,
fit this to the side plate with 1 screw. Turn it to tension the belt,
tighten the screw. Fit the clamp to the drum sprocket, leave untightened.
Run a length of plotter paper over the sprockets on the drum and platten.
Routate the latter so that all teeth enter holes on the paper and tighten
the clamp on the drum sprocket.
Fit the motor coupling to the motor and fit the clamp. Fit the cross
piece to the platten coupling, fit the motor to the side plate with the 3
screws and the spacers made earlier. Tighten the clamp on the motor
coupling. Check everything turns freely. Remove the motor and the
spacers. Fit the motor to the motor mount (1 screw and nut). The motor
wires are routed down the side of the motor, through a slot in the mount.
Fit this assembly to the mechanism, checking that the cross piece is
correctly engaged and that the cable is routed above the long screw on
the platten mouning. Fit the 3 motor screws and tighten. Plug the motor
cable into the motor harness and fit the connectors and cables into the
grouve on the side plate.
Fit the paper clamp assembly, 1 screw and large washer on one side, 1
screw and bush on the other. FIt the belt cover (2 screws), check this
latches the paper clamp
Fit the top cover on the paper sensor (5 screws)
Hello,
I have been able to figure out the LIF Directory format for HP 163x floppy
files. I will write up a doc for that. It is possible to mount a floppy
under Linux, set some parameters for the floppy drive, and dd it out to an
image file. This way one can read the floppy with the LIFUTILs out there...
In the XMas break I'll work on a doc to make that info available.
However, I'm also looking how a dir entry looks for for example an Inverse
assembler and executable code. There is a way to load a program on these
LA's and execute them.
Any idea's? Anyone on the list with an Inverse assembler for these units
(any will do) who can look at the directory with some simple instructions
for Linux?
Thanks,
Maurice
any gluey residues can be removed quite easily with a
product called Afta, available at hardware storer,
etc. It shouldnt harm most plastics, but its always a
good idea to test on an inconspicuous area. Please
dont be alarmed in the event of a spelling mistake.
--- cctech-bounces at classiccmp.org
<ard at p850ug1.demon.co.uk> wrote:
> >
> > All:
> >
> > Just a quickie.what would be a suitable
replacement for the opaque
> > labels that one would stick over EPROM windows? I
was going to use
> > electrical tape but it's so sticky and white
mailing lables leave glue
> > residue.
>
> I normally use the silver write-protect tabs you get
with 8" floppies.
>
> -tony
__________________________________________
Yahoo! DSL ? Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
The URL below contains several Epson PX4 manuals. Somebody (Dave?) was
asking for technical info on that machine. There's no service manual, but
there is the Operating System Technical Reference (it's the files
starting with 'osrm'). It's really a programmer's manual, so it doesn't
contain a full schematic, but it does contain I/O port details and
pinouts of the connectors (including the cartridge port), and examples of
how to design cartridges.
http://oldcomputers.dyndns.org/public/pub/rechner/epson/~fjkraan/comp/px4/d…
May be of interest, anyway...
-tony
>
>Subject: re: Good haul of old pc stuph
> From: Chris M <chrism3667 at yahoo.com>
> Date: Mon, 12 Dec 2005 17:50:26 -0800 (PST)
> To: talk <cctalk at classiccmp.org>
>
>There were a few XT IDE controllers back in the day.
>The one I still have is made by Acculogic, called the
>sIDE/16 or something. People who have used them claim
>they work well. Either this one was blown to begin
>with or the drive was at fault. It's mostly discrete
>logic, the exception being a GAL or PAL as I recall.
>There wasn't any firmware on it from what I remember.
>What did I do with the thing?
XT IDE adaptors are not uncommon and fairly simple devices.
I have one or two of them and could make one. They do work
well enough. The that drives usually connected to them
have usually died by age.
Allison
Yes, indeed it is...and to have wonderful something old under the
tree...hint, hint Santa!
Many blessings to all for this special time of the year.
Cheers!
Murray :)
Jules Richardson wrote:
That made we wonder... what's the oldest *operational* digital machine owned
by anyone on this list? Although I suppose it's hard to define 'machine' -
something with RAM, I/O in some form, and at least one CPU (what the heck do
you call a CPU when it's no longer central?)
I remember the discussions a while back about age of list members, but I
don't recall ever seeing a similar one about age of collections!
Not having all the peripherals that would have perhaps originally gone with
the machine is acceptable I think (I can see some people having room for a
mainframe and control desk, but probably not for a bazillion tape / drum
units to go with it!). But other than that, make it complete (i.e. things
like the single rack of EDSAC that we have - whilst perhaps "operational" -
doesn't count :)
(I'd quite like to hear responses from people with analogue machines too,
but someone else will be able to define qualifying rules much better than I
can)
Just out of curiosity!
cheers Jules
I don't have the oldest, I'm certain, but to throw my hat in the ring:
A Control Data 160-A manufactured in 1962. Has an Argonne Labs property
sticker on it. Still has original manufacturing log showing all ECOs
installed in factory and field.
And of course it is still operational - several list members have seen it
run. Internal paper tape reader and punch are operational. Has two
external peripherals, 161-A I/O typewriter ( not working but in restoration
) and 167-2 Card Reader (Operational).
There are a few vacuum tube machines out there, so surely there is one
working someplace - an LPG-30, RPC-4000 or G-15? Those are all late '50's,
so would qualify for oldest.
By the way to answer someone's question, all of my equipment is transistor &
diode logic. It predates ICs by several years. Core memory started with
vacuum tubes (or valves, if you prefer), moved to transistors and finally
ICs at the end of the era. I saw only a few commercial core memories with
ICs. ICs meant RAM was feasible, so there was a very narrow window of Core
and ICs. Many of those moved over to RAM in the middle of the production
runs. I think I still have an ECS board that is a hybrid - can be built
with either Core or RAM.
I was told that the origin of Core was from looking like Apple slices after
it had been cored. Apple corers were still available in the '50s and many
homes had one. If you cored an apple, then sliced it, you get a disk with a
hole cut out. I know my grandmother baked pies with both slices and wedges.
The wedges in years of plenty, the slices in lean times. And dried apple
slices were sold in the stores as a snack.
Billy
Date: Sat, 24 Dec 2005 00:14:58 -0600
From: Jim Leonard <trixter at oldskool.org>
Subject: Re: It's a most wonderful time...
Around the office today we kicked around "Merry Hannukwanzmas!"
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
--------------------------------------------------
Or check out the Virgin Mobile Christmahannukwanzaka Help Line:
1-888-353-7667
(In Canada; don't know if it works in the US)
m
I know they dumped a *lot*, but I thought there had been some
"official" dumping of what was left on CHM.
--
There are several hundred tapes at CHM from DEC LCG. Most of
the distribution tapes from the mid70's onward as well as backups
of all of the development machines are there.
I have suggested that they DO NOT just try reading these on the
tape drives that they have, and that they wait until a special
drive is available. I have been waiting for one of these drives
for several years now.
I would ask that people DO NOT encourage them to attempt to read
these until a way to read them without risking their damage is
available.
The machine that I had that I used most with core memory was a Seeburg
Jukebox. They used 1 core memory bit for each side of each record. If it
was a "1", that record had been selected for playing. The mechanism scanned
>from side to side, stopping at each record with the bit set for either side.
Records were not played in the order that they were selected or paid for,
but in the physical left-to-right or right-to-left order.
