cctech Digest, Vol 56, Issue 17

Mike michaelgreen42 at comcast.net
Mon Apr 14 12:35:06 CDT 2008


I've got a xceed setup I've been trying to figure out what to do with.
Might just end up on Ebay.

-----Original Message-----
From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org]
On Behalf Of cctech-request at classiccmp.org
Sent: Monday, April 14, 2008 10:01 AM
To: cctech at classiccmp.org
Subject: cctech Digest, Vol 56, Issue 17

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Today's Topics:

   1. Re: Help with ICL power supply fault (Farnell SMPS) (Tony Duell)
   2. Re: Mac Plus ozone? (Curtis H. Wilbar Jr.)
   3. Re: Schematics and description of an acoustic memory (1k
      byte,	Display terminal, 1969) (pichotjm)
   4. RE: modern switching power supply faults (dwight elvey)
   5. Re: pcmcia gpib on govliquidation  (Richard)
   6. Re: govliq: HP-1000 (Mechanicsburg, PA)  (Richard)
   7. Re: IBM 6094 Lighted Programmable Function Keypad - bulk buy
      on eBay (Paxton Hoag)
   8. Re: Mac Plus ozone? (Chuck Guzis)
   9. Re: modern switching power supply faults (Tony Duell)
  10. looking for replacement parts - 74S01, 74S73, 2518, 2533
      (Eric Smith)
  11. Re: looking for replacement parts - 74S01, 74S73, 2518, 2533
      (Eric Smith)
  12. Re: Schematics and description of an acoustic memory (1k
      byte, Display terminal, 1969) (Eric Smith)
  13. Re: Seeking Xceed Color30 card (Jeff Walther)
  14. Re: Seeking Xceed Color30 card (David Griffith)
  15. Bay Area collection viewing? (William Donzelli)
  16. Re: Seeking Xceed Color30 card (Cameron Kaiser)
  17. Big, heavy HP 7974 tape drive at BDI (Bob Rosenbloom)
  18. RE: OK, now this is impossible (11/23+ and RL02-RLV12
      problem) (Bob Armstrong)
  19. RE: modern switching power supply faults (dwight elvey)
  20. Re: Seeking Xceed Color30 card (Teo Zenios)
  21. Re: looking for replacement parts - 74S01, 74S73, 2518, 2533
      (Grant Stockly)


----------------------------------------------------------------------

Message: 1
Date: Sun, 13 Apr 2008 17:41:42 +0100 (BST)
From: ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Re: Help with ICL power supply fault (Farnell SMPS)
To: cctalk at classiccmp.org
Message-ID: <m1Jl5H0-000IxtC at p850ug1>
Content-Type: text/plain

> If you don't mind losing your second channel, you can always apply one
input 
> to channel A and the ground reference to channel B, then set the scope to 
> "A-B" mode (ChA subtract ChB). Most scopes can do this, and this is
exactly 
> what it's meant for.

If you do this, make sure the 'scope can stand a 'common mode voltage' of 
a few hundred volts, because that's what it's going to be seeing. I would 
think a fair number of 'scopes will not be happy looking at a signal of a 
few volts (so the Y attenuators are set to, perhaps, 1V/cm) with a common 
mode voltage of the full mains.

-tony


------------------------------

Message: 2
Date: Sun, 13 Apr 2008 09:32:36 -0400
From: "Curtis H. Wilbar Jr." <rescue at hawkmountain.net>
Subject: Re: Mac Plus ozone?
To: General Discussion: On-Topic and Off-Topic Posts
	<cctalk at classiccmp.org>
Message-ID: <48020B74.1000206 at hawkmountain.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

John Robertson wrote:
> Curtis H. Wilbar Jr. wrote:
>>
>> I was given a Mac Plus a while back... and never tested it....
>>
>> Decided to give it a quick test...
>>
>> Other than needing a boot floppy which I'll have to dig up.... it 
>> powers on, video
>> looks good, monitor is stable and all...
>>
>> But there is a faint sound (think of it as a cross between crickets 
>> chirping and clicks)
>> and after a while, it smells to me a bit like ozone at the top of the 
>> Mac.
>> I'm thinking maybe high voltage leakage ?
>>
>> Anyone have any experiences with these old Macs that can point me at 
>> what to look
>> for ?
>>
>> It might well be OK as it is... but I don't want to risk damage 
>> occuring as other
>> than a few dings and scrapes and a bit of yellowing, it is in 
>> remarkable condition.
>>
>> -- Curt
>>
>>
>>
> Ozone smell is just the high voltage at work. A slight leakage that 
> may indicate moisture or excessive dust on the monitor where the HV 
> lead clips to the side of the picture tube. You might be able to 
> reduce the smell by opening the case and (after waiting 24 hours to 
> discharge) clean the glass around the HV Anode clip (may have a rubber 
> disc protecting the clip) with a red (usually red) fat insulated wire 
> coming out of the picture tube cone. There is a special coating on the 
> tube that starts about 2 inches away from the anode clip and coats the 
> glass cone - do not remove or damage this if possible. It is 1/2 of 
> the capacitor element of the picture tube Lyden jar type capacitor.
Called DAG I believe.

I'll have to open this up, probably check it out in a dark room, then I 
can always
discharge with my hv meter or wait patiently for at least a day (and 
then double
check with the hv meter :-) ).

>
> Alternatively the flyback could be damp or filthy with dust. This is 
> found at the other end of the fat wire (normally red) leading from the 
> cone of the picture tube. You can wipe it with a damp cloth, taking 
> particular care not to rotate or move it relative to the frame - as 
> this will break wires and cause it to fail. Most flybacks are solid 
> enough that this is not a concern but in my early B&W video game 
> monitors the flyback coil was not well secured and subject to failure 
> from being turned or twisted whilst cleanig or just day to day 
> bouncing around...
>
which B&W video games ?  Vectors or Rasters ?  I have an Asteroids I haven't
repaired yet.  (I have around 12 vids, aprox half rasters, half 
vectors)  I am the
'repair shop' for them (but sadly get very little time, so several or 
awaiting repair).

Currently (off topic, but possibly of interest to some) on the repair 
room floor:
Star Wars (mathbox probs), Rip Off (sound problems), Tempest (flakes out 
with
large vectors and crashes randomly, might be bad ram socket from a ram 
someone
replaced), Major Havoc (mainboard problems, to be built into a Tempest 
cab), Xevious
(the dreaded Matsushita monitor is slewing video at the edge of the 
(rotated) screen),
and I'm sure I'm forgetting a couple.

My Joust leaks HV... I think the DAG coating has become damaged (flaked 
off, or
partially 'cleaned' off by someone).  Especially if there is moisture in 
the air, it
crackles, and IIRC I observed a faint lighting show around the DAG 
coating.  I
believe you can get a coating to redo the DAG, but I haven't researched 
that far yet.

OK.. enough off topic (hrm... maybe not too of topic.. they are 
essentially computers :-) ).

-- Curt

> John :-#)#
>



------------------------------

Message: 3
Date: Sun, 13 Apr 2008 16:02:08 +0200
From: "pichotjm" <pichotjm at free.fr>
Subject: Re: Schematics and description of an acoustic memory (1k
	byte,	Display terminal, 1969)
To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
Message-ID: <014b01c89d6e$f70fcb70$2601a8c0 at JM3800>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original


> Jean-Marie Pichot wrote:
>> This display terminal was designed in 1969,  [...]  Remember,
>> in that time, there are no micro-processor, neither RAM chips!

It was just to remind the common design context in 1969. There were some 
registers for computers or military products.
I have many young readers...

> There were RAM chips in 1969.  Most of them stored 16 bits or
> less.  I have not been able to determine when the first 64-bit RAM
> appeared, but it might have occurred by then.

Are they named RAM in databooks? or registers?
I think i have one, 4 bits but without adress decoding. There are 4 register

selects!

> Examples of RAM chips available in 1969 were the Fairchild U6A903059X
> 8-bit RAM and U6A903359X 16-bit RAM.  The base part numbers were 9030
> and 9033, respectively.  These were part of the CTuL Complementary
> Transistor Logic (CTuL or CTL) family.  Don't get confused by that
> name; these were complementary *bipolar* transistors, not CMOS.  Many
> years later Fairchild reused the CTL abbreviation for something entirely
> different, Current Transistor Logic.
> By the time of the 1972 Fairchild TTL Data Book, the 9033 designation
> was changed to 93433.
>
> The 9030 was used in the KM10 fast memory "option" for the DEC KA10, the
> first PDP-10 processor, designed in 1967.

Interesting!

> For a raster display terminal in 1969, delay line memory was obviously
> more practical than semiconductor memory, since the density of available
> RAM chips was too low.  This started to change in 1970 when Intel
> introduced the 1101 static RAM (256 bit) and the 1103 dynamic RAM
> (1024 bit), though there were initially a lot of reliability problems
> with the latter.

 I have a lot of MK4007 by Mostek. 256x1 i think similar to the 1101 by 
Intel. They are used in the Beryllium board: 
http://pichotjm.free.fr/1975-1980/Beryllium/PICT8117.html

> The next generation of raster display terminals used MOS dynamic
> shift register memory, which was less expensive than RAM.  As far
> as I'm aware, not many display terminal designs used RAM chips before
> 1977, and MOS shift registers were still being sold into the mid 1980s.

I have specification of a 32x4 bit shift register from RTC  (FDN 106, 
240.00 francs/1  # $50/1) dated 1970.
Other specs are for 256x4 512x2 and 1024x1 but unusable for raster scans. In

that time (1970) i remember to ask a company to develop a custom 80x8... but

the cost was too heavy.
Btw, i have specs of TTL used in that design, if anybody need them... (in 
french!)

JMP 



------------------------------

Message: 4
Date: Sun, 13 Apr 2008 07:16:31 -0700
From: dwight elvey <dkelvey at hotmail.com>
Subject: RE: modern switching power supply faults
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <BAY138-W132E3CC76D9E194B50669DA3E90 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"





> Date: Sun, 13 Apr 2008 00:56:47 -0400
> From: rescue at hawkmountain.net
> To: cctalk at classiccmp.org
> Subject: modern switching power supply faults
>
>
> I have two Dell switchers out of P4 based 1U servers.
>
> The first one has a failure in the startup circuit... pressing the power
> button will
> lead to a flash of the power light... and that's it.
>
> The second one failed spectacularly....
>

Hi
 I to have a problem with one.
 It is similar to your first one.
 Basically, the first problem is that something is failing to start
the switcher feedback. What happens on powerup is that it is
given one kick. This gets the 12v going to the regulator circuit.
It is then suppose to send pulses through the pulse transformer
to fire the switching transistors.
 It could be most anything in the regulation loop. I fixed one in
the past when I found an open wire in the pulse transformer.
Still, it could have been anything in the feedback path, including
regulator ICs, filter caps, diodes, resistors, etc.
 Mine is failing on a load related problem. As I connect more
load, it fails to powerup. It is funny that it seem to be more sensitive
to the loads that use the 12V. It seems to run the 5V loads fine.
 Your second one has most likely had a failed switching transformer
and switching transistor. There could also be a load issue, such as
shorted rectifier diodes on the secondary but that is unlikely. This
would tend to keep the 12V from coming up and you'd get no
pulses to fire the switching transistors. They're unlikely to fail if not
turned on.
Dwight

 
_________________________________________________________________
More immediate than e-mail? Get instant access with Windows Live Messenger.
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------------------------------

Message: 5
Date: Sun, 13 Apr 2008 11:23:14 -0600
From: Richard <legalize at xmission.com>
Subject: Re: pcmcia gpib on govliquidation 
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <E1Jl5v9-000256-00 at xmission.xmission.com>


In article <4801AC99.4050300 at Rikers.org>,
    Tim Riker <Tim at rikers.org>  writes:

> Is there any way to contact those who win an auction on govliquidation?

Nope.
-- 
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
      <http://www.xmission.com/~legalize/book/download/index.html>

        Legalize Adulthood! <http://blogs.xmission.com/legalize/>


------------------------------

Message: 6
Date: Sun, 13 Apr 2008 11:24:28 -0600
From: Richard <legalize at xmission.com>
Subject: Re: govliq: HP-1000 (Mechanicsburg, PA) 
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <E1Jl5wK-0002A7-00 at xmission.xmission.com>


In article <200804130758.05630.rtellason at verizon.net>,
    "Roy J. Tellason" <rtellason at verizon.net>  writes:

> On Saturday 12 April 2008 23:42, Richard wrote:
> > <http://cgi.govliquidation.com/auction/view?id=3D1675504&convertTo=3DUS=
> D>
> >
> > Buried in a giant lot of other stuff, 17 pallets, 7000 lbs.
> 
> I'm local to this,  though currently hauling 17 pallets is a bit beyond m=
> y=20
> capabilities.  :-)

You can enquire through the location if they allow you to haul it away
incrementally, otherwise I guess you have to rent a truck and manually
unpack it from the pallets into the truck.
-- 
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
      <http://www.xmission.com/~legalize/book/download/index.html>

        Legalize Adulthood! <http://blogs.xmission.com/legalize/>


------------------------------

Message: 7
Date: Sun, 13 Apr 2008 10:44:06 -0700
From: "Paxton Hoag" <innfoclassics at gmail.com>
Subject: Re: IBM 6094 Lighted Programmable Function Keypad - bulk buy
	on eBay
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID:
	<ded268c40804131044p1b41db1am5233047d3099642f at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

>  Did anybody purchase one of these?  How about getting it to work on a
> machine with a serial port not running AIX?


I got both lots. There were 11 people interested and I have filled
about 7 of the orders as people pay me for what they want. If you are
still interested let me know at paxton.hoag at gmail.com.

I have not tinkered with one except to take one with a broken key
apart. Parts available if needed. I still have a lot of them.
Pax
-- 
Paxton Hoag
Astoria, OR
USA


------------------------------

Message: 8
Date: Sun, 13 Apr 2008 11:03:19 -0700
From: "Chuck Guzis" <cclist at sydex.com>
Subject: Re: Mac Plus ozone?
To: cctalk at classiccmp.org
Message-ID: <4801E877.150.EBB4D0D at cclist.sydex.com>
Content-Type: text/plain; charset=US-ASCII

Date: Sun, 13 Apr 2008 09:32:36 -0400
> From: "Curtis H. Wilbar Jr." 

I believe the proper name for the water-based colloidal graphite 
suspension used to coat CRT surfaces is "aquadag". "Dag" is probably 
just a shortened form.  Aquadag paint for repair should still be 
available.

Some old HOTs (horizontal output transformers/flyback transformer) in 
CRT HV supplies develop cracks in the potting material with age and 
sometimes expose the connection of the winding to the HV anode lead.  
This can cause a corona discharge and the ozone smell.  There can 
also be arcing from the HV lead to the chassis.  A lights-out 
inspection will sometimes yield the telltale purple glow of corona 
discharge.  Often, the discharge can be heard by young ears as a 
"hissing" sound.

Good old red glyptal HV dope is the most commonly prescribed cure for 
insulation failures.  I think GC still sells the stuff.

Cheers,
Chuck



------------------------------

Message: 9
Date: Sun, 13 Apr 2008 17:51:44 +0100 (BST)
From: ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Re: modern switching power supply faults
To: cctalk at classiccmp.org
Message-ID: <m1Jl5Qh-000IxvC at p850ug1>
Content-Type: text/plain

> 
> 
> I have two Dell switchers out of P4 based 1U servers.
> 
> The first one has a failure in the startup circuit... pressing the power 
> button will
> lead to a flash of the power light... and that's it.
> 
> The second one failed spectacularly....
> 
> There is a wire wound power resistor (5W15RJ) near the AC input... it 
> cooked...

Di U deduyce from that marking that it's a 15 Ohm resistor?

Is it possibly part of a soft-start circuit, to be shorted out by a triac 
or similar once the supply has got going. If so, then if that fails and 
the resistor is left in circuit, it will overheat.

There have been supplies where there's a startup resistor -- to power the 
control circuitry until the rest of the supply gets going -- which would 
overheat if said supply took too long to get goiog. The resistor simply 
couldn't power the circuitry for long on its own. But I would expect such 
a resistor to be a lot more than 15 ohms

> and I do mean cooked.  It came out in pieces (with almost no effort), 
> melted the
> nearby capacitor and a nearby relay.  It also did a pretty good job of 
> puckering/burning
> the PCB (but not bad enough it could not be used).

What is that relay connected to/used for? It doesn't short out the 
reistor by any chance as part of a soft-start circuit, does it?

> 
> I suspected maybe shorted primary full wave rectifier... but I used the 
> DVM on
> diode test and got what I'd expect.
> 
> Oddly, despite there being a fuse on the primary side... it's still 
> good... it wasn't
> taken out.
> 
> That resistor got hot hot hot.  Could that resistor have failed on it's 
> own ?
> I suspect something further down the circuit must have a problem.
> 
> I'd be happy if I could make one power supply out of the two.  These are
not
> simple supplies however.  While much of the switching transistors, 
> regulators,
> bridge rectifiers, capacitors and the usual fair in a switcher are 
> pretty readily
> identified, there is a 6" x 1" "brain" board (I'll call it that as it 
> has adjustment
> pots, the ps fan circuit, quite a # of surface mount components on both 
> side of
> it, and it interfaces with the main PCB with 34 connections.
> 

Any recognisable chips on that board?

FWIW, there have been some very complicated SMPUs in classic machines. 
The HP9845B, a complicated machine in all respsects, has a PSU on a 
3-dimentional sculpture of PCBs, with 4 chopper transistors, 2 main 
chopper transformes, and IIRC 17 ICs on the control PCB.

-tony



------------------------------

Message: 10
Date: Sun, 13 Apr 2008 22:58:10 -0700 (PDT)
From: "Eric Smith" <eric at brouhaha.com>
Subject: looking for replacement parts - 74S01, 74S73, 2518, 2533
To: cctalk at classiccmp.org
Message-ID:
	<34656.68.121.162.227.1208152690.squirrel at ruckus.brouhaha.com>
Content-Type: text/plain;charset=iso-8859-1

It was recently asserted here that TTL parts aren't hard to find, but
I'm having a heck of a time finding the 74S01 and 74S73.

As far as I can tell from the data sheets, the 74S103 is functionally
and pin-compatible with the 74S73, but a little faster.  I wouldn't mind
substituting that, but it doesn't seem any easier to find.

The 74S03 and 74S107 are non-pin-compatible replacements for the 74S01
and 74S73, but I'd much prefer to stick with pin-compatible parts.

I'm also looking for the 2518 and 2533 shift registers.  The 2518 is
a hex 32-bit static shift register, and the 2533 is a 1024-bit static
(not dynamic!) shift register.  The original parts were Signetics, but
I don't mind using other sources:

    Signetics     2518          2533
    TI            TMS3122       TMS3133
    Fairchild     3349          3533
    National      -             MM5058
    GI            -             2533
    AMD           -             Am2833

Eric



------------------------------

Message: 11
Date: Mon, 14 Apr 2008 00:36:42 -0700 (PDT)
From: "Eric Smith" <eric at brouhaha.com>
Subject: Re: looking for replacement parts - 74S01, 74S73, 2518, 2533
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID:
	<39040.68.121.162.227.1208158602.squirrel at ruckus.brouhaha.com>
Content-Type: text/plain;charset=iso-8859-1

Grant wrote:
> Unicorn Electronics can get all of those ICs, but you'll have to
> order a minimum quantity.

None of them (other than the 74S03, which has the wrong pinout) are
listed on their web site.  If you mean that they can deal with parts
brokers at my request, I've tried dealing with the parts brokers
myself, and had poor results.  I'm willing to place an order for $250
total, but not for $250 for each line item, which seems to be the
minimum the brokers are willing to consider.

Eric



------------------------------

Message: 12
Date: Mon, 14 Apr 2008 00:51:33 -0700 (PDT)
From: "Eric Smith" <eric at brouhaha.com>
Subject: Re: Schematics and description of an acoustic memory (1k
	byte, Display terminal, 1969)
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID:
	<45219.68.121.162.227.1208159493.squirrel at ruckus.brouhaha.com>
Content-Type: text/plain;charset=iso-8859-1

JMP wrote:
> Are they named RAM in databooks? or registers?

The Fairchild 9030 and 9033 are described in the databook as an "8 Bit
Memory Cell" and "16 Bit Memory Cell", respectively.  They're obviously
read/write memory that is randomly addressable, so they are RAM.

I'm not sure about the 9030, but the 9033 uses "coincident select",
like core memory.  You provide a decoded one-of-four row address and
a decoded one-of-four column address.  "As many as four locations may
be addressed simultaneously without destroying stored information."

It was common for early RAM chips not to use a linear address.  Those
that did were often described as "fully decoded RAM".  The 9033 is
thus a "not fully decoded RAM".

Eric



------------------------------

Message: 13
Date: Sun, 13 Apr 2008 14:02:37 -0500
From: Jeff Walther <trag at io.com>
Subject: Re: Seeking Xceed Color30 card
To: cctech at classiccmp.org
Message-ID: <a04310101c42801b57c55@[192.168.1.10]>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"

>Date: Sat, 12 Apr 2008 15:04:29 -0700 (PDT)
>From: David Griffith <dgriffi at cs.csubak.edu>

>On Sat, 12 Apr 2008, Jeff Walther wrote:

>>  Now, it really shouldn't be that hard to whip something up with an
>>  FPGA and either some fastish SRAM or an open core DDR2 controller and
>>  one DDR2 memory chip.

>How far did you get with this project?  I'd love to see something that
>just does greyscale.  That and smaller modern parts would allow a lot more
>to be crammed into that PDS slot.

I would say I'm still in the conceptual stage.   I've examined the Is 
and the Os in the documentation and I pretty much know what I want to 
build, with a few choices still remaining (e.g. SRAM vs. DDR2). 
But I'm stymied by the details and by the fact that when I started 
this I was unemployed and had time, although my motivation was low 
due to the associated emotional challenges.   Now I am wonderfully 
employed, and very happy, but have very little spare time.

I've read through "Designing Cards and Drivers for the Macintosh" 
(IIRC) but I need to go through in more detail and draw a diagram of 
the ROM structure.   But it seems to me that some of what I need to 
know is in Inside Macintosh and extracting those tidbits is difficult 
(for me).  Also, some of the information I want to examine is 
contained in Pascal coding examples, and I don't know Pascal.  It 
will be easy enough to pick up, but it's another step back from the 
actual project.

Of course, all of the Apple documentation assumes that the audience 
is already an expert at building the component they want to build and 
only needs the Apple specifics, and I've never designed a video card. 
I haven't found any kind of book about it anywhere.   I picked up 
whatshisnames book about the video typewriter and the follow up book, 
but it doesn't seem quite applicable to this application.

So I'm in one of those situations where I need bits of information in 
order to truly understand other bits of information.   But I don't 
know in what order I really need the bits in order to make them 
comprehensible.   Worse, I don't actually know which piece will be in 
which resource.    So I need to find all the pieces of information, 
fail to understand them as I find them, but identify them, then after 
they've all been found, reorder them and go back, this time in 
logical sequence and put it all together.  Maybe if I was smarter, 
one pass would be enough...

I'm somewhere late in the finding all the pieces without 
understanding them yet stage, paused just before doing a quick learn 
of Pascal so I can examine/understand the examples in Inside 
Macintosh.   But I still lack a resource on the finer points of video 
card design.   I understand the basic fucntion, but there are always 
details which clever people have worked out, which a latecomer like 
me can greatly benefit from.

For example, the various schemes to avoid drawing the top half of the 
screen and then using changed data for the bottom half of the screen. 
I'm familiar with the simple expedient of having two screen buffers. 
But I understand that there are more elegant solutions in use, 
otherwise video cards would need twice as much VRAM.   Is it really 
all about tracking updates as they come in and only allowing ones 
which are earlier in the buffer than the current draw point, and 
delaying the others until the drawing point passes?   If so, one 
would either hold up the host system, or need an additional buffer 
for the delayed changes. Yes?  No?

As far as cramming a lot more into the PDS slot with smaller 
components...   Yes, the thing holding folks back is the time and 
skill to code, not the available technology.   Taken to its logical 
conclusion, we would take a moderate sized FPGA, emulate the 68030 
and FPU on board, put a fast memory interface on the FPGA, add a USB2 
chipset and fast ethernet I/O, plus an ATA interface and video 
outputs, then just use the SE/30 board as an I/O peripheral and home 
to the Apple ROM, with the built-in 9" screen as one display and a 
connector for a large color display if desired.

Alternatively, use a Coldfire MCU, patch the unimplemented 68030 
instructions with the exception handler (there's a library at 
Freescale for this) and then copy the basic design of the Daystar CPU 
upgrades which already worked out how to put a faster 68030 into the 
PDS slot.    With a little more work patching the firmware, one could 
use a Coldfire with built in USB and ethernet, but that's a lot more 
software work.   One also loses the FPU functionality, and if your 
code calls many of the unimplemented instructions it could be pretty 
slow.

But all those projects are dauntingly large.

For now, I'd like a video card.   Later, an ATA interface.   Maybe 
USB after that, but frankly, without a more skilled programmer's 
help, I don't think I will be able/willing to write USB drivers. 
Eventually, it could all go on one card.

Jeff Walther


------------------------------

Message: 14
Date: Sun, 13 Apr 2008 14:02:26 -0700 (PDT)
From: David Griffith <dgriffi at cs.csubak.edu>
Subject: Re: Seeking Xceed Color30 card
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Cc: cctech at classiccmp.org
Message-ID: <Pine.GSO.4.55.0804131400030.5772 at helios.cs.csubak.edu>
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Sun, 13 Apr 2008, Jeff Walther wrote:

> For now, I'd like a video card.   Later, an ATA interface.   Maybe
> USB after that, but frankly, without a more skilled programmer's
> help, I don't think I will be able/willing to write USB drivers.
> Eventually, it could all go on one card.

I wonder how much trouble it would be to figure out what's inside that
custom chip that Micron used.  Suitable SCSI drives are fortunately still
readily available.  I don't think USB was ever available for System 6.

-- 
David Griffith
dgriffi at cs.csubak.edu

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?


------------------------------

Message: 15
Date: Sun, 13 Apr 2008 19:09:22 -0400
From: "William Donzelli" <wdonzelli at gmail.com>
Subject: Bay Area collection viewing?
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID:
	<e1d20d630804131609lfc4c4e0rf8f7df4c11f28662 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Once again, this year I will be in the Bay Area for a few days,
basically most of the week of the 4th of May. In the past, a couple of
computer collectors opened their doors to me and did a show and tell.
Once again, thank you much.

So, does anyone else want to show of their machines to an East Coast
weenie? Remember, bigger is better. Microcomputers are only shims for
real computers. Computers with big blue skins are extra cool. Old is
good.

Let me know as soon as possible. I will have some email access as I
cross the country, but I always like to have things planned out before
I leave my driveway.

--
Will


------------------------------

Message: 16
Date: Sun, 13 Apr 2008 17:38:39 -0700 (PDT)
From: Cameron Kaiser <spectre at floodgap.com>
Subject: Re: Seeking Xceed Color30 card
To: cctalk at classiccmp.org
Message-ID: <200804140038.m3E0cd9d012732 at floodgap.com>
Content-Type: text/plain; charset=US-ASCII

> > For now, I'd like a video card.   Later, an ATA interface.   Maybe
> > USB after that, but frankly, without a more skilled programmer's
> > help, I don't think I will be able/willing to write USB drivers.
> > Eventually, it could all go on one card.
> 
> I wonder how much trouble it would be to figure out what's inside that
> custom chip that Micron used.  Suitable SCSI drives are fortunately still
> readily available.  I don't think USB was ever available for System 6.

I don't believe I have ever seen USB drivers for System 7 either.

-- 
------------------------------------ personal: http://www.cameronkaiser.com/
--
  Cameron Kaiser * Floodgap Systems * www.floodgap.com *
ckaiser at floodgap.com
-- Once used rectally, [it] should not be used orally. --Real thermometer
label


------------------------------

Message: 17
Date: Sun, 13 Apr 2008 18:25:10 -0700
From: Bob Rosenbloom <bobalan at sbcglobal.net>
Subject: Big, heavy HP 7974 tape drive at BDI
To: General Discussion: On-Topic and Off-Topic Posts
	<cctalk at classiccmp.org>
Message-ID: <4802B276.9000503 at sbcglobal.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

See:

http://www.auctionbdi.com/getpictures.asp?aucid=100131

Bidding ends tonight so if anyone's interested.....


Bob


------------------------------

Message: 18
Date: Sun, 13 Apr 2008 19:21:11 -0700
From: "Bob Armstrong" <bob at jfcl.com>
Subject: RE: OK, now this is impossible (11/23+ and RL02-RLV12
	problem)
To: "'General Discussion: On-Topic and Off-Topic Posts'"
	<cctalk at classiccmp.org>
Message-ID: <000001c89dd6$354537b0$9fcfa710$@com>
Content-Type: text/plain;	charset="us-ascii"

>It's not that.  XXDP runs fine with an RLV12.

  Thanks, Pete, Guy and Lyle (who phoned me) for the suggestions.  After
some poking around and much time spent peering into dark corners with a
flashlight, it turns out that the RLV12 is the source of the problem.  I
managed to borrow another RLV12 board and that one works fine, for both RSX
and XXDP.

  So, option #1 is that the first RLV12 is just bad, although oddly so as it
apparently works for RSX but not XXDP.

  However, I notice that the working RLV12 has a couple of ECO wires on it
that are absent from the "non-working" RLV12, and I can't help but wonder if
that has something to do with it.  Does anybody know the ECOs for the
RLV12/M8061 and whether they have any bad effects on XXDP?

Thanks again,
Bob



------------------------------

Message: 19
Date: Sun, 13 Apr 2008 19:59:20 -0700
From: dwight elvey <dkelvey at hotmail.com>
Subject: RE: modern switching power supply faults
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <BAY138-W334CC3BC797AA074CDA546A3E80 at phx.gbl>
Content-Type: text/plain; charset="Windows-1252"





> From: ard at p850ug1.demon.co.uk
---snip---
>
> FWIW, there have been some very complicated SMPUs in classic machines.
> The HP9845B, a complicated machine in all respsects, has a PSU on a
> 3-dimentional sculpture of PCBs, with 4 chopper transistors, 2 main
> chopper transformes, and IIRC 17 ICs on the control PCB.

Hi Tony
 I have a HP 21mx. The switcher in there is one of the most complicated
that I've ever seen. When I first got it, it took me a while of studying
the schematics before I realized it needed the resistor that was suppose
to be the thermal sense in the battery pack.
 This group was great in helping get the right value and connector.
 I think the switcher the fellow is looking at is the typical type used
in most PC's. It does sound like he may be able to get enough parts
to put together a working PS. It is at least worth a try.
 Both cases may have issued in the primary side though.
Dwight


_________________________________________________________________
Pack up or back upuse SkyDrive to transfer files or keep extra copies.
Learn how.
hthttp://www.windowslive.com/skydrive/overview.html?ocid=TXT_TAGLM_WL_Refres
h_skydrive_packup_042008


------------------------------

Message: 20
Date: Mon, 14 Apr 2008 01:56:55 -0400
From: "Teo Zenios" <teoz at neo.rr.com>
Subject: Re: Seeking Xceed Color30 card
To: "General Discussion: On-Topic and Off-Topic Posts"
	<cctalk at classiccmp.org>
Message-ID: <000801c89df4$5897bee0$c600a8c0 at game>
Content-Type: text/plain;	charset="iso-8859-1"


----- Original Message ----- 
From: "Cameron Kaiser" <spectre at floodgap.com>
To: <cctalk at classiccmp.org>
Sent: Sunday, April 13, 2008 8:38 PM
Subject: Re: Seeking Xceed Color30 card


> > > For now, I'd like a video card.   Later, an ATA interface.   Maybe
> > > USB after that, but frankly, without a more skilled programmer's
> > > help, I don't think I will be able/willing to write USB drivers.
> > > Eventually, it could all go on one card.
> >
> > I wonder how much trouble it would be to figure out what's inside that
> > custom chip that Micron used.  Suitable SCSI drives are fortunately
still
> > readily available.  I don't think USB was ever available for System 6.
>
> I don't believe I have ever seen USB drivers for System 7 either.
>

I think Mac OS 8.5/8.6 was the 1st to enable USB support.




------------------------------

Message: 21
Date: Sun, 13 Apr 2008 23:28:20 -0800
From: Grant Stockly <grant at stockly.com>
Subject: Re: looking for replacement parts - 74S01, 74S73, 2518, 2533
To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
Message-ID: <0JZB00JP30R4OIA0 at msgmmp-1.gci.net>
Content-Type: text/plain; charset=us-ascii; format=flowed


At 09:58 PM 4/13/2008, you wrote:
>It was recently asserted here that TTL parts aren't hard to find, but
>I'm having a heck of a time finding the 74S01 and 74S73.
>
>As far as I can tell from the data sheets, the 74S103 is functionally
>and pin-compatible with the 74S73, but a little faster.  I wouldn't mind
>substituting that, but it doesn't seem any easier to find.
>
>The 74S03 and 74S107 are non-pin-compatible replacements for the 74S01
>and 74S73, but I'd much prefer to stick with pin-compatible parts.


Unicorn Electronics can get all of those ICs, but you'll have to 
order a minimum quantity.

http://www.unicornelectronics.com/prod.htm 



End of cctech Digest, Vol 56, Issue 17
**************************************





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