RE: DEC VT20 boot device
>-Original Message-
>From: Jay Jaeger [mailto:cu...@charter.net]
>Sent: Saturday, August 10, 2019 11:02 PM
>To: Paul Birkel; General Discussion: On-Topic Posts
>Subject: Re: DEC VT20 boot device
>
>On 8/10/2019 1:56 PM, Paul Birkel via cctech wrote:
>> The DEC VT20 terminal apparently included a PDP-11/05 with a direct mapped
>> character display and was intended for text editing and typesetting. It
>> seems to have been followed by the VT21, and then VT71/VT72, all three based
>> on an LSI-11 (KD11-F). There's a real lack of documentation about these
>> online, although the VT72 does have a print set.
>>
>> Apparently the VT20 used the M792-YK as its bootstrap; the Field Guide is
>> silent regarding the boot device and M792 documentation stops earlier in the
>> series of variants.
>> ...
>> So . is the boot device in these systems the remote host via the serial
>> line? What protocol would that have been? Something native to Typeset-11
>> and DECset-11?
>>
>> paul
>
>I wonder if, maybe, it used the same protocol as the GT40, which also
>had a boot-over-serial line capability.
>
>JRJ
That's a promising lead! The GT40/42 User's Guide (EK-GT40-0P-002), Section
5.1 Communications Bootstrap/Read-Only Memory (ROM) describes a 256 word (GT40)
and 512 word (GT42) ROM, however it appears that the bootstrap loader portion
is intended to occupy 63 words which fits the M792 capacity (on the GT40 just
the absolute addresses 15700-15776 (base 8)).
Section 5.1.1 Bootstrap Loader describes the packed-and-serialized 6-bit "byte"
stream, including some nice diagrams. Section 5.1.2 Character Encoding
includes an illustrated example starting from a pictorialized 8-level paper
tape. Appendix D has an annotated (and unexpurgated) program listing of the
full GT40 ROM, including the loader and Figure D-1 Communications Bootstrap
Loader Flow Diagram. Program comments suggest that a PDP-10 was expected as
the host for a GT40. I imagine that the same expectation would have applied
for the earlier VT20?
Appendix E is similar, but for the "scrolling ROM - GT42" which appears to be a
VT05 emulation It includes more conventional loaders as well: RF11, RK11,
RC11, RP11, TC11, TM11, and paper tape. According to the program comments,
"the fearsome power of the 11" is brought to bear :->.
Both loaders are credited to Jack Burness.
If I understand the listings correctly then in the smaller VT20 ROM,
presumptively based on the same code, one would be expected to successfully
fall off the end of the ROM into freshly loaded code that signals back to the
host that a successful load has taken place. In the GT40 with the larger ROM
that acknowledgement ("SENDIT") is part of the ROM itself.
paul
Re: Pertec Interface Cable Length
On 8/10/2019 1:56 PM, Jon Elson wrote: On 08/09/2019 11:05 PM, Douglas Taylor via cctech wrote: I have a question about cable length - any electrical engineers in the house? Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller in a pdp-11/53. The interface is pertec with 2 50 pin cables. When I use a pair of short flat ribbon cables, 18 and 30 inches each, it works. Under RT11 I can INIT, Copy, DUMP, do a Directory. It doesn't work when I use a pair of 5 foot long flat ribbon cables. Are they too long? Do I need twisted pair type of cable? Is it possibly a termination problem? I have used cables about 20 feet long without trouble. The 2 50-pin cables is the Pertec formatted interface, which is really forgiving. Does you drive have terminators in both ends of the cable (both at the TC02 end and the drive end)? Now, I will mention that I have ONLY used twisted-pair ribbon cables with both flavors of interface, never straight ribbon cable. Jon I haven't checked to see if there are terminators (Arnold the Terminator) on either end. I did check the long cables for continuity and found no problems. It may be an EMI problem. Would folding the excess cable up and covering with anti-static plastic help? Doug
Re: DEC VT20 boot device
On 8/10/2019 1:56 PM, Paul Birkel via cctech wrote: > The DEC VT20 terminal apparently included a PDP-11/05 with a direct mapped > character display and was intended for text editing and typesetting. It > seems to have been followed by the VT21, and then VT71/VT72, all three based > on an LSI-11 (KD11-F). There's a real lack of documentation about these > online, although the VT72 does have a print set. > > > > Apparently the VT20 used the M792-YK as its bootstrap; the Field Guide is > silent regarding the boot device and M792 documentation stops earlier in the > series of variants. > > > > According to the VT72 print set, it used the MRV11-VC (M9942-YC; described > in the Field Guide as a "bootstrap/diagnostic module") for its bootstrap but > is also silent regarding the boot device. In interestingly, the Field Guide > also describes a MRV11-AA (M7942-TB) as a "M7942 with VT52 emulator, VT71 > bootstrap". > > > > For async. communications the VT20 used a DL11-B (M7800 (EIA)). the VT72 a > DLV11-F (M8028). > > > > Looking in a DEC "Options and Modules" listing I see VT20 bundles including > Typeset-11 and DECset-11, and it appears that the VT20 could be configured > with two displays & serial lines in a single 11/05. > > > > So . is the boot device in these systems the remote host via the serial > line? What protocol would that have been? Something native to Typeset-11 > and DECset-11? > > > > paul > > I wonder if, maybe, it used the same protocol as the GT40, which also had a boot-over-serial line capability. JRJ
DEC VT20 boot device
The DEC VT20 terminal apparently included a PDP-11/05 with a direct mapped character display and was intended for text editing and typesetting. It seems to have been followed by the VT21, and then VT71/VT72, all three based on an LSI-11 (KD11-F). There's a real lack of documentation about these online, although the VT72 does have a print set. Apparently the VT20 used the M792-YK as its bootstrap; the Field Guide is silent regarding the boot device and M792 documentation stops earlier in the series of variants. According to the VT72 print set, it used the MRV11-VC (M9942-YC; described in the Field Guide as a "bootstrap/diagnostic module") for its bootstrap but is also silent regarding the boot device. In interestingly, the Field Guide also describes a MRV11-AA (M7942-TB) as a "M7942 with VT52 emulator, VT71 bootstrap". For async. communications the VT20 used a DL11-B (M7800 (EIA)). the VT72 a DLV11-F (M8028). Looking in a DEC "Options and Modules" listing I see VT20 bundles including Typeset-11 and DECset-11, and it appears that the VT20 could be configured with two displays & serial lines in a single 11/05. So . is the boot device in these systems the remote host via the serial line? What protocol would that have been? Something native to Typeset-11 and DECset-11? paul
RE: Pertec Interface Cable Length
> -Original Message- > From: cctech On Behalf Of Mark J. Blair via > cctech > Sent: 10 August 2019 18:03 > To: General Discussion: On-Topic Posts > Subject: Re: Pertec Interface Cable Length > > > > > On Aug 10, 2019, at 1:57 AM, Dave Wade via cctech > wrote: > > > >> > >> I have a question about cable length - any electrical engineers in the house? > > > > Its electronics, rather than electrical engineering. Electrical Engineering is > power distribution. > > At least in the US, "Electrical Engineering" applies to both subfields. Same > university department, same degree name, same generic title of "electrical > engineer"; just different specializations. I presume from your remark that an > "electrical engineer" in the UK would be an engineer who works in the field of > power generation and distribution. Yes.. > What term is used there for an engineer > who works in fields of general electronics? > An electronics engineer... > > -- > Mark J. Blair, NF6X > http://www.nf6x.net/ Dave G4UGM
Re: Pertec Interface Cable Length
On 08/09/2019 11:05 PM, Douglas Taylor via cctech wrote: I have a question about cable length - any electrical engineers in the house? Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller in a pdp-11/53. The interface is pertec with 2 50 pin cables. When I use a pair of short flat ribbon cables, 18 and 30 inches each, it works. Under RT11 I can INIT, Copy, DUMP, do a Directory. It doesn't work when I use a pair of 5 foot long flat ribbon cables. Are they too long? Do I need twisted pair type of cable? Is it possibly a termination problem? I have used cables about 20 feet long without trouble. The 2 50-pin cables is the Pertec formatted interface, which is really forgiving. Does you drive have terminators in both ends of the cable (both at the TC02 end and the drive end)? Now, I will mention that I have ONLY used twisted-pair ribbon cables with both flavors of interface, never straight ribbon cable. Jon
Re: Pertec Interface Cable Length
On 8/10/19 9:45 AM, Douglas Taylor via cctech wrote: > I bought the long cables off ebay, so they have to be good? Right? I > think the short cables came from a hamfest. > > The cables can be fairly long, I remember interfacing a TU80 to an > Emulex QT14 (maybe) and the DEC cables were round and about 15 feet > long. And it worked. Of course it did--the TU80 hews to the Pertec inteface spec. The Qualstar, as I observed, does not. It's basically "Pertec on the cheap". It might be interesting if someone with a Qualstar 1xxx series drive who's using 10' flat ribbon cables can report their success. I suspect that you'll hear crickets... The point of the Qualstar drives is that they were cheap--and the design reflects that. --Chuck
Re: Pertec Interface Cable Length
> On Aug 10, 2019, at 1:57 AM, Dave Wade via cctech > wrote: > >> >> I have a question about cable length - any electrical engineers in the house? > > Its electronics, rather than electrical engineering. Electrical Engineering > is power distribution. At least in the US, "Electrical Engineering" applies to both subfields. Same university department, same degree name, same generic title of "electrical engineer"; just different specializations. I presume from your remark that an "electrical engineer" in the UK would be an engineer who works in the field of power generation and distribution. What term is used there for an engineer who works in fields of general electronics? -- Mark J. Blair, NF6X http://www.nf6x.net/
Re: AIX 5L/ia64 media?
On 7/25/19 5:07 AM, Plamen Mihaylov via cctech wrote: I know it was a short lived, but anyone has the installation cd or iso image? I was actively involved with AIX as an IBM contractor till 2010 and as a hobbyist user since then. I've never heard even a rumor that such media exists, much less of anyone running it. The short version, from my perspective: I was teaching AIX admin courses at the time, and learned of the ia64 port when it was mentioned in some beta course material. I tried to track down any solid information with the AIX guys here in Austin and my Linux contacts in Durham NC. The official AIX for ia64 beta release, and later the licensed product in 2001/2002, wasn't available for customer installation, or as a media set for customer use. (IBM's later statements that AIX/ia64 was a request-for-quote only item supports that.) It wasn't even called AIX, at least within IBM, it was "Monterey". Further, IBM was not the sole marketing source for Monterey - Caldera/SCO Group and IBM were both marketing Monterey and paying each other royalties. Officially, that is. I've never found any record or rumor of SCO actually selling a copy. This last is mostly scuttlebutt and surmise, but anyone who has worked with IBM will recognize the mindset. When SCO started the infamous IBM lawsuit, I strongly suspect that IBM Legal scoured the planet for Monterey media and made it Gone. Doc
Re: Pertec Interface Cable Length
On 8/10/2019 4:57 AM, Dave Wade wrote: -Original Message- From: cctech On Behalf Of Douglas Taylor via cctech Sent: 10 August 2019 05:06 To: General Discussion: On-Topic Posts Subject: Pertec Interface Cable Length I have a question about cable length - any electrical engineers in the house? Its electronics, rather than electrical engineering. Electrical Engineering is power distribution. Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller in a pdp-11/53. The interface is pertec with 2 50 pin cables. When I use a pair of short flat ribbon cables, 18 and 30 inches each, it works. Under RT11 I can INIT, Copy, DUMP, do a Directory. So the hardware is good. It doesn't work when I use a pair of 5 foot long flat ribbon cables. Are they too long? Do I need twisted pair type of cable? Is it possibly a termination problem? I can't see 5 foot being too long for data from a tape, the data rates aren't huge. At most you have added 10ns to the delay times. On the other hand I have been wrong in the past and could be wrong again.. I assume you have checked the cables. Ribbon cables are prone to come loose from the IDC pins if it’s a IDC connector, and if soldered can break Doug Dave G4UGM I bought the long cables off ebay, so they have to be good? Right? I think the short cables came from a hamfest. The cables can be fairly long, I remember interfacing a TU80 to an Emulex QT14 (maybe) and the DEC cables were round and about 15 feet long. And it worked. It was too late last night to begin checking the long cables for continuity, so I fired off the email instead thinking it may be a termination problem. Is it possible for the IDC and Card edge connectors to be put on wrong? You would want pin 1 to map to pin 1, and so on. Doug
Re: I'm sharing a toy
> On Aug 9, 2019, at 12:00 PM, cctech-requ...@classiccmp.org wrote: > > Thanks for putting it up. First time I've logged > onto old Unix in decades (should try getting my copy of V6 up on simh). > Have a couple of RasberryPi's kicking around that > just fired up once to play with. Only part that > simulation doesn't let you do is to connect up > all sorts of lab hardware to A/D's and > D/A's. Have lots of PDP-11 code that wrote in > 1980's that can't use as no-one has written > additions to PDP-11 emulators which will make one > think one is dealing with 80's era data > acquisition hardware and digital I/O boards which > are far faster on modern microprocessors than there were then. Boris, I am very interested in PDP-11s and laboratory data acquisition with A/Ds etc. I have a MINC-23 (upgraded to an 11/73) that I’ve put a SCSI2SD card in and run RT-11, and RSX11M. Recently the RT-11 FEP/FRP and RGL software packages were recovered from a couple RL02 packs in Austrailia. Also, on another PDP-11/73 I converted a ADV11-A (18 bit) to a ADV11-C (22 bit) and have it talking with the Kseries routines under RSX11M+ as well as to a M+ A/D driver that I wrote by combining code from David Cutler’s AD01 RSX11M Driver with Lee Gleason's M+ BM180 driver for the PiDP-11/70 that Adam just mentioned in his post. Certainly the I2C devices could be extended to create some Actual I/O device with chips like the ADS1015 which is available on a small board from AdaFruit that would be easy to stick in a PiDP-11. https://www.adafruit.com/product/1083 I would be VERY interested in getting a copy of your PDP-11 code for data acquisition with A/Ds, DIOs, etc. Thanks, Mark
RE: Pertec Interface Cable Length
> -Original Message- > From: cctech On Behalf Of Douglas Taylor > via cctech > Sent: 10 August 2019 05:06 > To: General Discussion: On-Topic Posts > Subject: Pertec Interface Cable Length > > I have a question about cable length - any electrical engineers in the house? Its electronics, rather than electrical engineering. Electrical Engineering is power distribution. > > Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller > in a pdp-11/53. The interface is pertec with 2 50 pin cables. > > When I use a pair of short flat ribbon cables, 18 and 30 inches each, it > works. Under RT11 I can INIT, Copy, DUMP, do a Directory. > So the hardware is good. > It doesn't work when I use a pair of 5 foot long flat ribbon cables. Are they > too > long? Do I need twisted pair type of cable? Is it possibly a termination > problem? I can't see 5 foot being too long for data from a tape, the data rates aren't huge. At most you have added 10ns to the delay times. On the other hand I have been wrong in the past and could be wrong again.. I assume you have checked the cables. Ribbon cables are prone to come loose from the IDC pins if it’s a IDC connector, and if soldered can break > > Doug > Dave G4UGM
Re: Pertec Interface Cable Length
> It doesn't work when I use a pair of 5 foot long flat ribbon cables. > Are they too long? Do I need twisted pair type of cable? Is it > possibly a termination problem? These cables typically were twisted pair, at least inside cabinets. (They might transition to round cables at bulkheads before routing to other cabinets.) I've seen them in lengths of like 20-30 feet. De
