Re: Value of 7-track TU10

2016-09-20 Thread Michael Thompson 

> From: j...@mercury.lcs.mit.edu
> Subject: Value of 7-track TU10
> 
> So what do people think the (monetary) value of a 7-track TU10 master drive
> is? I have no idea what these older vacuum-column drives are worth - don't
> recall ever seeing on for sale. This one is in good condition, and has all its
> Flip Chips.  The 7-track is a plus in some ways (rarer), and negative in
> others (can't read old 9-track tapes, which are probably more common than
> 7-track).
> 
>Noel

Noel,

The TU10 would be a great addition to the PDP-9 at the RICM.

The RICM is a 501(c)(3) entity so you get a tax deduction for a donation.

Re: VCFMW 11, downloads

2016-09-20 Thread Jörg Hoppe 

Jay, Jason & others,

thanks for all the organization

>
>
> To my eye, attendance was up this year yet again.
>
...

> The touch screen 11/70? Front panel connected to emulation was awesome!

The simulations are for download at
https://github.com/j-hoppe/BlinkenBone/releases


My photos are at ftp://jhoppe.ddns.net/vcfmw2016/


see u,

Joerg

Re: 68K Macs with MacOS 7.5 still in production use...

2016-09-20 Thread Liam Proven 
On 16 September 2016 at 14:51, David Bridgham  wrote:
> On 9/15/16 23:13, ben wrote:
>
>> PS: Ternary arithmetic I can understand, but Ternary Logic needs Mr
>> Spock to figure out.
>
> Ternery logic would seem to be useful for implementing an asynchronous
> design instead of, say, dual rail encoding.


Huh? But there have been several -- the Russian/Polish SETUN was the
first committed to hardware.

http://www.computer-museum.ru/english/setun.htm

But there have been others:

https://en.wikipedia.org/wiki/Ternary_computer

One chap is even trying to build his own:

https://hackaday.io/project/1043-base-3-ternary-computer-from-scratch

-- 
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Decoding kryoflux stream for HP9895A

2016-09-20 Thread Denise de Vries 
Does anyone know of documentation for the HP9895A format with its own M2FM 
encoding?


I have a kryoflux preservation stream but so far can make no sense of it.


Denise

Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Julian Wolfe 


So the DSD-440 I got at VCF is completely unresponsive.  All of the LEDs are on 
and never go out, which is bizarre - they are supposed to go out in 1/10 of a 
second after power on.



I tried disconnecting everything but power to the card, and it still lights all 
LEDs.  No jumpers that I could find are in the wrong spot, but many are 
seemingly undocumented ( I looked in both the 1981 user manual and 1984 service 
manual on Bitsavers).



The drive just spins and does nothing else.  Altering the switches on the 
control board do nothing to change the state of the LEDs.



I measured voltages at the power supply, and they seem to be within spec 
according to the manual.



Are there any other things I can try before I start digging into things on a 
component level?

Re: Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Jerry Weiss 
On Sep 20, 2016, at 12:49 PM, Julian Wolfe  wrote:
> 
> 
> 
> So the DSD-440 I got at VCF is completely unresponsive.  All of the LEDs are 
> on and never go out, which is bizarre - they are supposed to go out in 1/10 
> of a second after power on.
> 
> 
> I tried disconnecting everything but power to the card, and it still lights 
> all LEDs.  No jumpers that I could find are in the wrong spot, but many are 
> seemingly undocumented ( I looked in both the 1981 user manual and 1984 
> service manual on Bitsavers).
> 
> 
> The drive just spins and does nothing else.  Altering the switches on the 
> control board do nothing to change the state of the LEDs
> I measured voltages at the power supply, and they seem to be within spec 
> according to the manual.
> 
> 
> Are there any other things I can try before I start digging into things on a 
> component level?
> 

This is a failure of the  DC  Power Up/Down circuit - See page 3-10 + 3-53/54 
in June 83 
Service Manual.   If the components in this circuit (capacitor) are out of 
spec, then this may be the cause.

Congrats on picking it up. I was tempted to bid for it as well, but I already 
filled had my boat anchor quota.   

Is the Green LED on?

Jerry

Re: Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Julian Wolfe 
Both green LEDs are on.  They're ALL on.





This is a failure of the DC Power Up/Down circuit - See page 3-10 + 3-53/54 in 
June 83 

Service Manual. If the components in this circuit (capacitor) are out of spec, 
then this may be the cause. 

 

Congrats on picking it up. I was tempted to bid for it as well, but I already 
filled had my boat anchor quota. 

 

Is the Green LED on? 

 

Jerry

Re: Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Jerry Weiss 
On Sep 20, 2016, at 1:37 PM, Julian Wolfe  wrote:
> 
> Both green LEDs are on.  They're ALL on.
> 
> 

As LED 9 is on (sorry for not being clear), then the CPU is active.  That’s a 
good sign.

Definitely look at the DC Power up/down circuit first.  

Jerry

Re: Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Julian Wolfe 
After reading this section, I should probably bring up that when I checked the 
PSU voltages, the 5v+ line was low, at 4.7v or so.  I adjusted it back to 5.05v 
on the pot as defined in the manual, and there it stayed steady, but it didn't 
seem to help.  Before I adjusted the pot, it was fluctuating.




 On Tue, 20 Sep 2016 11:47:17 -0700 Jerry Weiss wrote 
 




On Sep 20, 2016, at 1:37 PM, Julian Wolfe  wrote: 

> 

> Both green LEDs are on. They're ALL on. 

> 

> 

 

As LED 9 is on (sorry for not being clear), then the CPU is active. That’s a 
good sign. 

 

Definitely look at the DC Power up/down circuit first. 

 

Jerry

Re: Need help: DSD-440 with unresponsive formatter/control board

2016-09-20 Thread Jerry Weiss 
On Sep 20, 2016, at 2:02 PM, Julian Wolfe  wrote:
> 
> After reading this section, I should probably bring up that when I checked 
> the PSU voltages, the 5v+ line was low, at 4.7v or so.  I adjusted it back to 
> 5.05v on the pot as defined in the manual, and there it stayed steady, but it 
> didn't seem to help.  Before I adjusted the pot, it was fluctuating.
> 
> 

Given the age of the unit, its not surprising that the potentiometers are a 
noisy, have drifted/aged and/or are contaminated with crud. 

SYSTEM Reset L should be High.  If Not then Check for 1.1V on THR.

Re: Decoding kryoflux stream for HP9895A

2016-09-20 Thread Eric Smith 
On Tue, Sep 20, 2016 at 7:42 AM, Denise de Vries
 wrote:
> Does anyone know of documentation for the HP9895A format with its own M2FM 
> encoding?
> I have a kryoflux preservation stream but so far can make no sense of it.

I've successfully decoded Intel M2FM disks.  The track-level format
isn't the same as the HP 9895A, but the channel code is.  I'd be happy
to take a look at a 9895A image.