test-drb

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101090 discussions

by billdeg＠degnanco.com

> > I have a Vector Graphic's ZCB cable that is wired for a 9600b 8/n/1 serial > terminal. It was working yesterday, but the connections were brittle and a > few of the wires have come loose from the 25-pin connector. I can see the > spots where the solder was applied but I am not confident that I have the > correct repair points. Does anyone have the pinouts for this cable so I > can re-solder/replace? <snip> I believe this is the answer to my question page 10 of http://vector-graphic.info/vg_zcb.aspx (download/part 2) Bill

15 years, 10 months

Commodore C 900 documentation and software required ...

by jfoust＠threedee.com

At 02:43 PM 6/15/2010, Brian Lanning wrote: >On Tue, Jun 15, 2010 at 2:30 PM, Zane H. Healy <healyzh at aracnet.com> wrote: >> I assume most of us have never seen a C900. I need to google it, as I'm >> curious as to what it actually is. I remember seeing one at CES in '85 or so. I saw one or two since then, back in Amiga days. Secret Weapons says 500 units were produced. I would guess that CBM would've sold as many as they could, which isn't quite the same as saying they were all scrapped. I think I have an AMIX tape and tape drive in the basement somewhere, for the A2500. - John

15 years, 10 months

Senzig S-100 boards

by jfoust＠threedee.com

A year or so ago, Jim Battle passed along a tip from the brother of Don Senzig, a Milwaukee area S-100 devotee who passed away leaving a collection of old boards. I eventually received them. Here's a quick overview: http://www.flickr.com/photos/37817884 at N07/?saved=1 Are there any gems there? I'm not an S-100 collector, (although if an IMSAI fell in my lap I've take it (having helped my high school computer club build one, once upon a time.)) I'm open to ideas about disposing of these boards. I don't have any reason to keep them. - John

15 years, 10 months

Moreo n the HP82909 RAM module

by ard＠p850ug1.demon.co.uk

I've spent a bit more time looking at the HP82909 128K RAM module for the HP86/HP87 machines which I mentioned a few days ago. I think I know what the missing chips are -- a pair of '30s, a '27 and a '74. Thers's also a resistor (around 4k7?) and a transistor (TUN :-)), not fitted as well. And a mode control link or switch which enables this extra circuitry (and changes a couple of other logic signals that I've not fully investigated yet) if these parts were present, then it appears a write to location 0xFFC7 would enable or disable the internal system ROMs of the HP85/87 (bit 0 of the data written determines whether the ROMs are enabled or disabled. I don't know enough about the custom RAM controller IC in the module to know if it can be programemd to map the RAM in place of the system ROMs, or if a differnt controller IC is needed too. I am wondering what this was designed for? Developing new versions of the ROMs? Has anyone come across anHP product which could make use of this capability? -tony

15 years, 10 months

RK05 data problems with misaligned drive?

by hachti＠hachti.de

Hi folks, I'm just reviving a completely misaligned RK05 drive. I want to get it fully up and running and tested before I use an alignment pack. So I started debugging and got it to the point that I can play with the formatter. Here comes the question: The formatter (RKLFMT under OS/8) threw MANY CRC errors when reading back the freshly formatted disk. Changing the head cables at the drive proved that the problem is only with one head i.e. the failures change "side" when you change the head plugs. Now I ran the test several times. With random failing disk addresses. And they decreased and decreased... Now I've run two error-free formatter rounds. Could it be possible that new data on new tracks (keep in mind that the drive is actually misaligned by means of mechanical alteration!) suffers from interference from old tracks? That's the only reason I can see for this kind of behavior. On the other hand that would mean that I'd have to degauss the pack before I ever could use it reliable again. Any ideas? Kind regards, Philipp :-) -- http://www.hachti.de

15 years, 10 months

pinout for Vector Graphic's ZCB cable

by billdeg＠degnanco.com

I have a Vector Graphic's ZCB cable that is wired for a 9600b 8/n/1 serial terminal. It was working yesterday, but the connections were brittle and a few of the wires have come loose from the 25-pin connector. I can see the spots where the solder was applied but I am not confident that I have the correct repair points. Does anyone have the pinouts for this cable so I can re-solder/replace? A picture says a 1K words. I am not sure I have an original cable. I will keep looking and if I find the answer I will post it here. Thanks Bill

15 years, 10 months

Programing PDP-8 assembler - details

by bqt＠softjar.se

Ethan Dicks <ethan.dicks at gmail.com> wrote: > On Fri, Jun 11, 2010 at 1:09 PM, Ben <bfranchuk at jetnet.ab.ca> wrote: >> > Johnny Billquist wrote: >> > >>> >> Why use a line editor? There are several full screen editors for OS/8. >>> >> Really fast and nice ones. >> > >> > Where? > > I just know of one - VTEDIT.TE > > http://www.pdp8.net/os/os8/os8_cmd.shtml > > I had unhappy results with a VT220 in VT52 mode 25 years ago, but it > works great with a real VT52. I seem to remember using it just fine with a VT320 though. I think you had to make sure you set it to 7M1 or something like that, and not use 8N though, or else it wouldn't be pretty. I totally forgot that I wrote a Emacs-clone for TECO8, which is what I normally use. That one I have probably not posted anywhere anytime. But we also have VISTA, which was available from DECUS, and which I have. I think I made it available, and maybe others have too. So for people in general, you have atleast two options, and I should post my EMACS.TE sometime too... Johnny

15 years, 10 months

yet another pdp-8 in a fpga, but this time running tss/8

by dave＠mitton.com

On 6/8/2010 09:54 AM, cctech-request at classiccmp.org wrote: >Message: 17 >Date: Mon, 7 Jun 2010 16:45:00 -0400 >From: Brad Parker <brad at heeltoe.com> >Subject: Re: yet another pdp-8 in a fpga, but this time running tss/8 >To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> >Message-ID: <D71821FC-0C2B-4891-ACF6-C4835EF9DBDE at heeltoe.com> >Content-Type: text/plain; charset=us-ascii > > >On Jun 6, 2010, at 7:02 AM, Jerome H. Fine wrote: > > > > > (a) Without being very accurate, and based on your experience > with the PDP-8, how > > long do you think that it would take you to implement a > PDP-11? Just a rough estimate > > in months or years! > >um. I already did that. It took a few years, but I only worked on >it sporadically. It currently >boots (in simulation) RT-11, RSTS V4, BSD 2.9 and V6. I have not >debugged the split I & D >but it's there. > >If you send me a RK05 image with TSX on it I'll try and boot it in sim. > >The last FPGA version I did had no MMU but it did boot RT-11. It had >some disk problems which >I have since corrected. I believe I could synthesize and run the >"no mmu" version pretty quickly. >The mmu version need still needs some work do make 50mhz timing. > > > (b) About how fast might the FPGA solution be compared to > something like a PDP-11/93? > > Again, just a rough estimate like 10 or 20 times as fast. > >Well, as I said, the no-mmu version runs at 50MHz. I could improve >that. The mmu version probably >won't run faster, mostly due to the 20ns rams on my fpga board. > > > Any idea why you did an FPGA implementation of the PDP-8? > > >back in the day I spent a lot of time on TSS/8. I wanted to run it >again :-) And, I want >to work on cpu's when I grow up. > >I also spent a lot of time on RSTS and TSX, hence the pdp-11. > >I know the s/w sims are better, but I like hardware and love running >h/w simulations. > >-brad > >Brad Parker >Heeltoe Consulting >781-483-3101 >http://www.heeltoe.com Now what would be really cool would be to make 4 CPUs and re-create an 11/74 quad. http://www.miim.com/faq/hardware/multipro.html#castor Dave.

15 years, 10 months

Paging Richard

by pat＠computer-refuge.org

Sorry to eat up bits on the list, but I've tried sending you a few emails from two different addresses, but haven't seen any reply from you (re: the SGI Onyx XL). Pat -- Purdue University Research Computing --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

15 years, 10 months

Lightbulb police? (was RE: Anyone off to VCF-UK)

by IanK＠vulcan.com

Are you kidding? We can't fund enough people to deal with important things like education, health and public safety, and people really think we are paying people to watch *lightbulb sales*? I think someone's tinfoil hat is too tight.... -- Ian ________________________________________ From: cctalk-bounces at classiccmp.org [cctalk-bounces at classiccmp.org] On Behalf Of William Donzelli [wdonzelli at gmail.com] Sent: Wednesday, June 02, 2010 2:49 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Anyone off to VCF-UK > I cannot find the primary legislation, and I bet if I could I'd > regret it :-) > > Here's one retailer's opinion: > http://www.lightbulbs-direct.com/info/incandescent/ > > Here's another actually selling them: > http://www.lyco.co.uk/Light-Bulbs/Regular-Light-Bulbs/Rough-Service-Bulb > s/sc1340.aspx What I have heard from all this lightbulb talk, as well as other issues - in the US, everything you read is crap, unless you are looking at the text of the law. There are many people with axes to grind, and will even use lightbulbs to do it. > Apparently in the US the sales of alternatives (like rough service > bulbs) are being > monitored and action may be taken if sales go up too much. or maybe not, > who knows. Lightbulb cops? No, there is no monitoring. > Same as the analgesics packaging rules: if you make it inconvenient > to go around the rules, most people won't be bothered. Job done. Pretty much like the various copy protection systems software has used over the years. -- Will

15 years, 10 months

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