test-drb December 2015

test-drb@ccmp.vtda.org

191 participants
268 discussions

Best 200 buck I have ever spent!!! Deal of a lifetime!!!

by COURYHOUSE＠aol.com

many high paid cios started with a vic 20 or a c 64! everyone has their treasured first.... Ed# In a message dated 12/9/2015 11:34:32 P.M. US Mountain Standard Time, mhs.stein at gmail.com writes: Surprised to see so much interest in C64s on a 'serious' list... m

9 years

Four-phase non-overlapping clock generator using PIC microcontroller

by spacewar＠gmail.com

In the 1970s, some microprocessors and support chips used four-phase NMOS logic. Some, including the Rockwell PPS-4 and PPS-8, generated the four non-overlapping clock phases on-chip based on two external clock inputs, while others, including the TI TMS9900, the Western Digital CP1600 chip set (used in DEC LSI-11 and Alpha Micro AM100), and the WD9000 chipset (used in Pascal Microengine), required an external four-phase clock generator. Typically the four-phase clock inputs required a voltage swing close to the Vss and Vdd supply rails (0 to +12V). TI and Western Digital offered support chips to generate the four-phase clock, although it was often done with a crystal, 74S logic, and MOS drivers such as the National Semiconductor MH0026 dual MOS driver or the Intel 3245 quad MOS driver. I've recently had occasion to work on interfacing to some of these old chips, and wanted a modern four-phase clock generator. I've just written and tested code to use a Microchip PIC16F1575 as a clock generator, though it only has 5V outputs, so it will require external gate drivers, such as a Microchip TC4469 quad gate driver, to obtain the 12V swing. The PIC16F1575 is a fairly new part using Microchip's enhanced midrange core. It is in a 14-pin package, has an internal oscillator, PLL, and four 16-bit PWM modules. The PWM modules can operate independently, but for this purpose it was convenient that they can be synchronized. I've configured the PIC to use the 8 MHz internal oscillator, with a 4x PLL for a 32 MHz clock going into the processor and the PWM modules. The CPU speed doesn't matter, but that gives timing resolution of around 31ns for the PWM. I've configured the PWMs for a period of 16 clock cycles (500 ns, 2 MHz), clock high pulses of three clock cycles (93ns), and delay between phases of one clock cycle (31ns). This could be trivially changed to a 2.67 MHz clock by reducing the period to 12 cycles and hte clock high pulses to two clock cycles (62ns). Either set of timings is within the specifications of the TI and Western Digital parts. A word of caution: when using gate drivers to drive old NMOS parts, I recommend the use of series resistors of at least 10 ohms and schottky diode clamps to Vss and Vdd, to ensure that undershoot and overshoot (due to ringing) are limited to 0.3V. The C source code is released under the GPLv3 license on github: https://github.com/brouhaha/4phaseclk

9 years

DEC MM15 core mem found

by j_hoppe＠t-online.de

I help cleaning out a large repository of DEC parts. There a quantity of DEC core module assemblies appeared. According to PDF docs these must be PDP-15 MM15's, but no labels are on the boards. I show/offer some of them at retrocmp.com/flipchipshop , under "core memory" Can somebody confirm they are MM15's? Are any PDP-15 running at all? Thanks, Joerg

9 years

CDC Finch Alternatives Today [WAS:RE: Evotek Winchester Harddisk]

by t.gardner＠computer.org

The manual u cited states, "The disk controller can control either a CDC or Finch drives. All drives attached to any controller must be of one type." I'm not sure what they mean by "CDC" but if u are lucky it might mean "SMD." According to the 1983 Disk/Trend Finch interfaces were available on the Wren 9415-32 (Finch and ST506) and the Wren 94153 (Finch only). So u might look for a 94153 or a Finch variant of the 9415-32. The Finch spec data interface specs include 13440 unformatted bytes per revolution using an 806 KB/sec data rate, which are the very old at that time 3330 industry standards. There are very few small drives that use this standard, not even the 94153 (10,080 @ 605 KB/sec) so what happens with the drive at a different frequency and the controller with a possibly a different number of raw bytes per track is unpredictable. Note that 10080 x 806/605 is close enough to 13440 so any 10,080 @ 605 KB/sec drive might be made to work if the recording channel has margin at the higher frequency; unfortunately there are not very many. A bigger problem might be the command and control interface of the Finch - it is not like the ST506/412. Off the top of my head it looks like a variant on SMD. BTW SMD data specs are exactly 1.5x3330, that is 20,160 bytes @ 1.209 MB/sec so a small SMD might work if the recoding channel can deal with the lower data rate, perhaps the 8715 FSD. You might want to compare pin by pin SMD to Finch to see if this is even possible. There were some small SMDs, e.g. Micropolis 1403, Priam 804 but most were 14-inch. Perhaps there is a CDC SMD expert in this group that can help Tom -----Original Message----- From: Oliver Lehmann [mailto:lehmann at ans-netz.de] Sent: Monday, December 07, 2015 11:39 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Evotek Winchester Harddisk Tom Gardner <t.gardner at computer.org> wrote: > Sorry If I didn't make myself clear, I am suggesting one never acquire > an Evotek drive today other than perhaps as an historical curiosity. > > > > The Finch was a short lived 8-inch HDD that went up to 42 MB > unformatted BUT according to Disk/Trend It did not use an ST506 > interface but instead came with this variety of interfaces: Finch, > LDI, SMD or SA1000! So your problem is likely to be finding a drive > that matches the interface of yr controller card. Some possibilities > > Finch interface was available on certain CDC Wren 5 -inch > models, e.g. 9415 > From what I understood in the Zilog System 8000 manuals, it is the Finch interface. http://bitsavers.informatik.uni-stuttgart.de/pdf/zilog/s8000/03-3237-04_hwR… Page 33 - Drive Performance Characterstics Page 47 - Pinout of the WDC-Controller Disk Connector Page 65-69 - Describing Driver Configurations Here are pictures of harddisks used in the System 8000: http://pics.pofo.de/gallery3/index.php/S8000/Harddisk And this is the so called "FINCH Adapter Board" used in the S8000: http://pics.pofo.de/gallery3/index.php/S8000/S8000_boards/FINCH-Adapter-Boa…

9 years

Looking for a PERQ

by earl＠baugh.org

> > This is a laughable ask, I realize that- but I'd really like to find a > PERQ. > > Anywhere in the US and Canada is fair game. I am prepared to work on one in > any condition, and am okay with any model. > > I'm definitely not asking for a handout and would like to negotiate a > reasonable price. (I am aware of the rarity!) > > Please contact me off-list if this is a possibility. > > For reference, I am located in Seattle, WA. > > Cheers, > > - Ian > I know there are 4 or so in your area, but I don't think any are available. The newest one acquired is a PERQ-1 (and it is in good condition...boots just fine.... ..and just got the report that it booted about a week ago after the chassis with HD arrived) Only problem is we don't know the password for the user (and the guest account is disabled). I know about it, because I rescued it for him out here in Atlanta. And I only rescued it because I had knew Skeezics was a fan from some postings on sun-rescue years ago. I almost gave him a heart attack when I told I had picked it up and it was his, he just had to pay shipping... (it has an interesting history, I was able to contact the guy who orignally purchased it and used it at an architectural design firm he ran, some of the floppies with it are designs for jails... ) The guy who got it >from him picked it up at a garage sale he had and was able to squeeze chassis, monitor, etc. into a Smartcar and get it home (with his wife). When I called the original owner he said this was the last one he had (bummer) but he remembers them fondly (and I was even able to find a picture of one in the history part of his company web site... not sure if it's the actual unit I picked up, but could be... ) I don't believe Skeezics is on cctalk, but he has a number of them. Lots of good stories, his Dad worked at 3Rivers.... Skeezics I beleive also has the OS source and got the last machine that they had left when they closed down. He works on the emulator, etc. and has been chatting with Al about PERQs as well... If you want to see about visiting his collection let me know... Earl the Squirrel

9 years

Anyone interested in old (PDP-8 driven) Radio Automation hardware?

by COURYHOUSE＠aol.com

our phx station had an 8E with one backplane in it and a single diablo hard drive. would be great to buy one of these for the museum . Ed# _www.smecc.org_ (http://www.smecc.org) In a message dated 12/9/2015 7:19:06 A.M. US Mountain Standard Time, radiotest at juno.com writes: At 11:53 PM 12/8/2015, wulfman wrote: >The "carts" were 4 track tapes. They were not. They were either 2 track for mono or 3 track for stereo, and they were physically different from, and not interchangeable with, consumer tape cartridges. Radio carts were introduced in, IIRC, the early 1960s (I would have to check my broadcast equipment catalogs) and predate the Lear 8 track cartridges. Dale H. Cook, Radio Contract Engineer, Roanoke/Lynchburg, VA http://plymouthcolony.net/starcityeng/index.html

9 years

TEST

by tulsamike3434＠gmail.com

Tihis is my first post to the group I just want to make sure that everyone can see this and that I have it setup right please reply if yall can see this.

9 years

Looking for a PERQ

by ian.finder＠gmail.com

This is a laughable ask, I realize that- but I'd really like to find a PERQ. Anywhere in the US and Canada is fair game. I am prepared to work on one in any condition, and am okay with any model. I'm definitely not asking for a handout and would like to negotiate a reasonable price. (I am aware of the rarity!) Please contact me off-list if this is a possibility. For reference, I am located in Seattle, WA. Cheers, - Ian -- Ian Finder (206) 395-MIPS ian.finder at gmail.com

9 years

R: Looking for AS/400

by supervinx＠libero.it

Can't help, since I live on the other side if the pond, but AS/400s are cool machines. I own a bunch of them (and some S/36s too) and I like them. OS/400 was and is a good OS (if you have clear in mind what it can and what it can't do). Meanwhile, you could request a free AS/400 access to the folks at pub1.rzkh.de and play with OS/400. It's fun to access such a beast from a... Smart Phone :) -------- Messaggio originale -------- Da: Brian Adams <fink at stenoweb.net> Data:07/12/2015 21:58 (GMT+01:00) A: cctalk at classiccmp.org Oggetto: Looking for AS/400 Hi there, Recently, I've been reading up into AS/400s.. They seem like really neat machines, and look really sharp with those matching block terminals. I remember retail stores using those, and I always wondered what kind of a system they were running on... I figured it was DOS! I've been having trouble locating one, however. Anybody have one lying around, or know of where to find one in the Toronto area? It needn't be a high spec machine, just something to play with OS/400 and a terminal. Thanks! -brian

9 years

Anyone interested in old (PDP-8 driven) Radio Automation hardware?

by derschjo＠gmail.com

Hi all -- I have recently acquired a PDP-8/m system that was used to drive a radio automation rig (very very similar to this: http://www.bowkera.com/kcbs1.htm ). My understanding is that this system hooked to banks of what were essentially 8-track tape drives, each of which held a short loop of tape (containing a song, an ad, call info, etc.) and the 8/m was programmed with a playlist of sorts so that even in the early 70s you didn't need to have a real DJ on premises to run a radio station. (I had no idea this sort of thing went back that far!) This one was used at KRDU (Fresno's Christian Radio). At any rate, it's neat hardware. All I have is the 8/m, a custom front panel (as seen in the pictures on the site I linked above) and a bank of Omnibus backplanes holding cards that would drive the tapes and mix audio. I really have no use for the tape-control / audio mixing hardware since I don't have the tapes and I'm not *really* planning on running an automated radio station out of my basement (though it does sound fun). I'm not about to scrap the stuff (it's at least useful for parts) but I thought I'd see if anyone out there could actually make use of it for its intended purpose. - Josh

9 years

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test-drb December 2015