Hi Jim
There are several things that can couse problems.
It might be that you are being too fast, not too slow.
Most of the newer serial chips hold a larger buffer.
Several characters may be buffered up in the chip.
You need to make sure that the character has been
sent and that you've waited for enough delay time
for your other machine to respond before sending
another character to the serial chip. You can't just
handshake on the status lines from the serial chip.
You may have to look at the time chip for timing
information.
Also, I assume you are using the system calls. If
not, you may have issues if your running under windows
or in a DOS box under windows because windows thinks
it owns the serial and will periodically steal characters
>from the input. There is a way to remove a serial port
>from windows but I've never tried it for this particular
problem.
Dwight
>From: "Jim Beacon" <jim at g1jbg.co.uk>
>Hi,
>
>has anyone tried to write a paper tape emulator in BASIC? I've had a go in
>GW-BASIC, but I suspect that the implementation of the language is too slow
>to reliably drive the serial port - it doesn't always pick up the paper
>advance signal (I've tried using both CTS and DCD as inputs).
>
>Will I have to go to a machine code routine to get the fast port access?
>
>I look forward to replies.
>
>Jim.
>
>Please see our website the " Vintage Communication Pages" at WWW.G1JBG.CO.UK
>
>
>From: ard at p850ug1.demon.co.uk
>
>> Certainly, multifunction tubes were around - the first ones were the dual
>> diodes and rectifiers of the 1920s, then later twin triodes, extra diodes,
>> and yes, to the ultimate Compactrons.
>
>The most complex common multi-section valve in the UK (i.e. with the most
>sections), is the triple diode triode. It came with a variety of heater
>ratings -- the EABC80 (6.3V heater), UABC80 (100mA series string heater,
>by far the most common version) and the oddball PABC80 (300mA series
>string heater). It turned up in numerous AM/FM radios in the 1960s, where
>it was used for the AM detector (1 diode), FM detector (the other 2
>diodes) and audio ampifier (triode).
Hi
Higher quality AM receivers used the two diode tubes.
One diode was for the detector while the other was
used for the AGC. That way the loading could be optimized
for each function.
Dwight
It has a B9A (9 pin miniature) base,
>so there must be some commoning of electrodes going on, probably the
>cathodes.
>
>-tony
>
>
I've noticed something odd with my 8" disk drive. It seems to produce a
lot of errors on the last tracks on side 1 when using Anadisk. Anadisk
will report "Gap in sector" and "Data error" errors, usually on tracks
higher than 70, and always on side 1. The errors are also inconsistent.
I use Anadisk to do a disk dump and note down the errors on one pass, then
do it again and compare the errors on the second pass to the first and
they are invariably different. I used the sector editor to read one track
over and over several times. On most tries it gets errors. The errors
are inconsistent from read to read. Sometimes some sectors will have
"Gaps", other times data errors, and occasionally the entire track reads
just fine.
I have dumped some disks that are otherwise error free and the dumps have
been consistent.
What does "Gap in sectors" under Anadisk mean anyway?
Is this just a case of disks that are just old and wearing out or
something weird with my drive?
Yes, I've cleaned the drive head, thoroughly. But that wouldn't explain
why this is only happening on the higher tracks now, would it?
Thanks!
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
First.. I am looking for SDI drive cables for a PDP
11/84 that I just picked up at the salvage yard. Its
in great condition but unfortunately, it was
deinstalled with wire snips. Also looking for a
manual, DEUNA, RL11 for it as well.
Haven't tested the RA80 that came with it but the RA60
sounds like it needs bearings BAD. Any suggestions on
restoring this RA60 would be appreciated.
Is it true that that the NPG jumpers are missing on
all of the slots requiring the G727A grant cards?
Also looking for anything on the VAX 6000 series. I
have a 6000-510 that I would like to load up. Looking
for extra CPU cards and any XMI options. Also would
like to find a VAXBI backplane for it as well as VAXBI
modules.
I have some original IBM PC's, a Kaypro, HP laserjet
printers, maybe some SUN stuff and I have a SUN V100
to trade for something really good.
I have access to a lot of surplus older SUN's and
Apples too for decent trades.
Thanks,
Brian.
Also looking for a
manual, DEUNA, RL11 for it as well.
--
http://www.bitsavers.org/pdf/dec/pdp11/1184
Something that would be nice to find are docs on the 94, and engineering
drawings for either the 84 or 94. They appear to be very difficult to find.
Brad,
Looks like tgis is a good one so I will be hanging
onto it for now. I'll let you know if I come across
another one.
Brian.
--- Brad Parker <brad at heeltoe.com> wrote:
>
> Brian Roth wrote:
> >
> >Haven't tested the RA80 that came with it
>
> I could use an RA80 HDA if you (or anyone else) has
> one they don't need.
> I have a full RA80 box, but no HDA for it.
>
> You probably want the ra80 for your '84, however.
>
> No idea about ra60's, sorry.
>
> -brad
>
Hi Sellam,
>What does "Gap in sectors" under Anadisk mean anyway?
It means that ANADISK saw gaps in the sector numbering.
For example, it might have seen sectors:
1 2 3 4 6 7 8 9
In this case there is a "gap" which is sector #5 missing.
Note, it is entirely possible to format a diskette with
missing sectors - but most people didn't do it - it most
likely indicates that ANADISK failed to read one sector,
which is why it reports this as a warning.
>Is this just a case of disks that are just old and wearing out or
>something weird with my drive?
The higher the track, the smaller the "circle" on the disk with the
data, hence the more densly packed the bits are - which can lead to
more errors - this is also the area where head alignment etc. can be
most critical, and worn drives do tend to give more errors on the
inner tracks.
But it's may also be a incompatibility between the diskette format and
the PC disk controller (I am assuming this is the 8" drive that you
have hooked up to a PC).
The PC disk controller cannot handle gaps sizes as small as some
other systems did - For example, I find that Cromemco disks do not
read reliably on my PC. The interesting thing is that certain sectors
consistantly do not read on one PC, while DIFFERENT sector(s) may not
read reliable on a different PC.
When I was working on my replacement for TELEDISK (which I still have
not gotten back to), I found that I could sometimes read all the sectors
by re-reading the same track multiple times (however at that point you
lose the ability to detect the exact interleave), but sometimes even
reading the track 50 times would not yield all the sectors. On a different
PC, I could read a different set of sectors with about the same
reliability. One thing I wanted to add to the program was the ability to
merge multiple images read from different PCs into one to "collect" all
the sectors.
I also found that slowing the drive slightly can make a big improvement
on reading some types of disks...
(and of course - none of this may actually relate to the problem you are
having ... just some of my experiences to help you figure it out)
If you format a disk from the PC can you read it back reliably?
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
Please no flames.... but back in my younger days when
I used to (hack?) the Telenet X25 PADs, it seemed like
every other machine I ran into was a Prime with its
familiar "Primos" banner. I also had a grad student
that worked for me that HATED the one he used in
school so much that he bought it years later at the
Universities surplus auction, held a party and handed
out sledge hammers to everyone. You can guess the
rest.
Of all the years purusing the salvage yards, I have
never seem one. Interesting.
Brian.
--- Jay West <jwest at classiccmp.org> wrote:
> It was written....
> > To say that they must have been quite common
> machines at one point,
> > there are very few left unfortunately - I'm
> surprised there aren't more
> > survivors.
> They were definitely common machines at one point...
> I worked on hundreds of
> them literally.
>
> > Actually, I don't know of anyone else on this list
> who has any kind of
> > PR1ME, but doubtless someone does...
> I know of a couple listmembers who have one or
> two...
>
> I don't, and would very much like one :)
>
> Jay West
>
>
>
Ok, Ethan.
I had the impression you were searching for a 2 or 3,
and was thinking of doing a "job" on a 'READY' 6 or 7.
I do not need the 6 or 7 as I will never have that many RK07 drives
for several reasons - limited space for one, power, cables, etc.
It is all in my museum, so hardly "heavy use" here :~)
The 6 and 7 were a nice addition to my collection (hint - hint).
Actually, I have never seen a 'READY' higher than 3!
I hope to install the 230VAC power cabling within a few weeks.
6 groups, secured with 16A. fuses, but those 6 groups are derived
>from a single 3-phase 25 A. source. So I can "only" load the six
16A groups to a max of say 70A provided the load is distributed
evenly. But running a 11/70 with TU77 and two RM03's ... yeah.
I have an option to "upgrade" the 3-phase connection to 3x 35 A
but I guess I will be needing an airco too when drawing that much!
cheers,
- Henk.
> On 5/2/05, Gooijen H <GOOI at oce.nl> wrote:
> > Hello Ethan,
> >
> > I have 3 RK07 drives (two connected) and I have no READY "buttons"
> > with numbers higher than 3. So before you start a job on your 6
> > or 7, would you consider a trade? You get a 2 and a 3 (or whatever
> > you want), and I get the 6 and the 7. Instead of working with a
> > rasp to remove some plastic, you have to walk to the Post Office :~)
>
> I had no plans to modify my higher numbers. I was trying to suggest
> to people that if they had access to higher numbers they could use
> them intact in an RL01/RL02 and the drive itself would treat them as
> lower numbers (there are 2 microswitches in the RL drives, 3 in the
> RK drives).
>
> I would be willing to loan my numbers to Vince to copy (if he wants
> to try), but since they are the only ones I have over 3 as well, I'd
> prefer not to trade them away. I used to have a pair of RK07 drives
> and a score of packs, but they didn't survive the closing of Software
> Results 12 years ago (I had to leave them behind because they were
> too large to transport/store).
> Someday, I hope to replace them, but it's not a huge priority (they
> are easier to repair than more modern drives, but on a MB/volume/kWH
> curve, they are hard to justify for heavy usage).
>
> -ethan
Hello Ethan,
I have 3 RK07 drives (two connected) and I have no READY "buttons"
with numbers higher than 3. So before you start a job on your 6
or 7, would you consider a trade? You get a 2 and a 3 (or whatever
you want), and I get the 6 and the 7. Instead of working with a
rasp to remove some plastic, you have to walk to the Post Office :~)
kind regards,
- Henk.
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Ethan Dicks
> Sent: maandag 2 mei 2005 5:54
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: I made a zero (was Re: Stuff I want - all I want
> is a "0")
>
>
> On 5/1/05, vrs <vrs at msn.com> wrote:
> > OK, here's the followup on my attempt to make an RL02 "0":
> >
> > http://so-much-stuff.com/pdp8/zero.html
> >
> > I think it turned out pretty well for a first attempt.
>
> Nice job. I was recently going through a box of plastic bits (to put
> away the handles I got from you, coincidentally), and found a 6 and a
> 7, from an RK07, no doubt (since the RL01/RL02 switches top out at
> 3)... IIRC, one can use them modulo 3 in an RL01/RL02 (i.e., these
> would work as 2 and 3) if one doesn't happen to have a full load of
> RK07s to populate with numbers.
>
> My recollection of the old days was that 1s and 2s were harder to find
> that 0s, but probably because we never misplaced our 0s... they were
> right there on the system drives. Somewhere in some old DEC
> reseller's warehouse there has to be an enormous box of numbers...
> much like teeth in the fabled elephant's graveyard.
