test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dhquebbeman＠theestopinalgroup.com

> Unless I'm mistaken, the 7980XC is a current production drive. At least it > was about a year ago. You should be able to still get complete docs direct > from HP. Apparantly, they don't want to admit it being an HP product on their web site, as I can't find it through the usual means. -dq

25 years, 11 months

Looking for....

by LFessen106＠aol.com

In a message dated 7/5/00 1:03:22 PM Eastern Daylight Time, elmo(a)mminternet.com writes: > > IIRC ADM-5's have gone unsold on Ebay at $19-24 for some time, from > more than one seller. The latest seller has quantity and includes a > transport > case. Exhorbitant? > > I just re-checked Ebay's past and present sales and found 1 (one) sale of ADM terminals....Currently going for $24.00. Seller has 4, HOWEVER, they are going AS IS. I would like to find a <working!> ADM 3 or 5 preferably from someone qualified enough to make that judgement. You see, $24 would be a lot of money with a $60 shipping charge for a broken dumb terminal. -Linc.

25 years, 11 months

HP Tape drive

by steverob＠hotoffice.com

> > Great drive (If it's the same as the one they OEM'd to Pyramid). > 1600/6250 bpi. > > It's fast and reliable. Is it the SCSI, Pertec or other version. > HPIB... I've been looking for documentation on the web but, haven't found any :-( Steve Robertson <steverob(a)hotoffice.com>

25 years, 11 months

TRS items taken - Re: newbie intro

by aclark＠envirolink.org

A person in my state has expressed willingness to come to my home and pick up the TRS items. Since such an arrangement would relieve me of the time demands of packing and shipping the items, I have given that person first chance to get all of it. Once he has looked at it, I will repost to the ClassicCmp mailing list regarding what is still available. Thanks for your interest. Arthur Clark

25 years, 11 months

New find: HP 1000 E series

by fmc＠reanimators.org

Carlos Murillo <cem14(a)cornell.edu> wrote: > Well, I made the cable and plugged it into a terminal. The > right voltages appear on the correct lines. However, > the card never asserts DTR or RTS when I turn the computer on. I think that makes sense -- it looks like DTR and RTS are under program control (i.e. it's up to software to set the appropriate control register bits). > I also discovered that the HD in the 7946 is busted > (haven't opened it yet)-the "online" light doesn't come on, > but the "fault" light does. It seems to have trouble > spinning up. So, loading an OS is out of the question > for a while. Is it possible to at least run some tests > and have it output diagnostics to one of the BACI cards? I suspect it depends on what loader ROMs are installed in the computer. There is a loader ROM that supports booting from cartridge tape drives in an attached 264X terminal. In the meantime, I've keyed in the sample program from the manual (at the end of this message). Turning it into executable code and loading that into the 1000E is left as an exercise for the reader, at least 'til I find time to figure out how to do that sort of thing. Others who know are welcome to chime in! > There is a sheet of paper glued to the front panel with instructions > on how to reboot the system; it says to load the S/s register > with ones in bits 15,14,9, and 6, then hit the store, preset, > some other button, then preset again and finally the run button. Unfortunately, most of the 21xx documentation I have here at home right now is for 2100s, not 21MXs (which are a whole lot closer to 1000s), so I'm just guessing as to what that tells the machine to do, but I expect it's instructions for selecting a given loader ROM (and maybe device) and starting the boot. So...I'll try to keep this in mind for the next foray into storage. What I probably need to look for is the 21MX or 1000 E-Series operating and reference manual, instead of the installation and service manual that I have in front of me. --- cut here --- ASMB,A,B,L,T ORG 100B * ****12966 SAMPLE PROGRAM************************* *THE PROGRAM BEGINS BY CLEARING ALL ADDRESSES OF THE *SPECIAL CHARACTER RAM TO ZEROS.THE 12966 THEN IS *ENABLED TO RECEIVE MODE,1200 BAUD.THE USER ENTERS A *MINIMUM OF 64 CHARACTERS FROM THE TERMINAL KEYBOARD *(HP2640 OR SIMILAR TERMINAL). WHEN BUFFER HALF FULL *(64 CHARS.) IS DETECTED,THE CHARS. ARE TRANSFER FROM *THE FIFO BUFFER OF THE 12966 TO THE CPU. WHEN THIS *TRANSFER IS COMPLETE THE CPU HALTS (HLT 01).THE USER *PRESSES 'PRESET' & 'RUN', THE 12966 GOES INTO THE *TRANSMIT MODE. THE CPU BUFFER (64 CHARS.) IS SENT TO *THE 12966 FIFO BUFFER. WHEN THIS TRANSFER IS COMPLETED *THE 12966 TRANSMITS TO THE TERMINAL UNTIL BUFFER EMPTY *STATUS FLAG SETS. THE CPU NOW HALTS (HLT 02),PRESSING *'RUN' RESETARTS THE PROGRAM. * * A EQU 0 B EQU 1 SCT EQU 12B 12966 IS IN SELECT CODE 12B SAVA BSS 1 SAVB BSS 1 COUNT BSS 1 SIZE DEC 64 64 CHARACTERS BHF OCT 1000 CW3 OCT 030023 CW4R OCT 040011 CW4T OCT 140411 CW5 OCT 050077 CW6 OCT 060000 PAT OCT 777 DAB. DEF DAB CLEAR OCT 060400 ORG 1000B DAB BSS 400 * * ORG 200B START LDA CW4T MASTER RESET,INITIALIZE TRANSMIT OTA SCT LDA CW6 CLEAR OUT SPECIAL CHAR RAM R1 OTA SCT INA CPA CLEAR CHECK IF SPECIAL CHAR RAM IS CLEAR RSS YES IT IS,CONTINUE WITH PROGRAM JMP R1 NO IT ISN'T,CONTINUE CLEARING OVER LDA SIZE SETUP AND INITIALIZE CHAR COUNTER CMA,INA 2'S COMP. STA COUNT LDA CW5 LOAD WORD 5,CLEAR FLAGS OTA SCT LDA CW3 LOAD WORD 3,1 STOP BIT,8 DATA BITS OTA SCT ECHO ON,NO PARITY LDA CW4R LOAD WORD 4,RECEIVE MODE,1200 BAUD OTA SCT CHECK STC SCT,C SET CONTROL 12966 SFS SCT CHECK IF STATUS FLAG SET JMP *-1 NO,NONE IS SET,CONTINUE CLC SCT YES,FLAG HAS SET LIA SCT GET STATUS WORD AND BHF CHECK FOR BUFFER HALF FULL SZA,RSS JMP CHECK BHF NOT SET AS YET LDA CW5 BHF SET,CLEAR STATUS FLAGS OTA SCT LDB DAB. SETUP CPU BUFFER ADDRESS STC SCT,C SET CONTROL 12966 T1 LIA SCT GET A CHARACTER FROM FIFO AND PAT MASK OUT UNWANTED BITS STA B,I STORE CHAR INTO CPU BUFFER INB ISZ COUNT INCREMENT COUNT,COUNT=64? JMP T1 NO,GET NEXT CHARACTER HLT 01 YES,CPU BUFFER IS FULL ***PRESS 'PRESET' AND 'RUN' TO PUT 12966 INTO TRANSMIT *MODE. * NOP LDA CW4T SETUP 12966 TO TRANSMIT @1200 BAUD OTA SCT LDA CW5 CLEAR BUFFERS OTA SCT LDA SIZE SETUP CHAR COUNTER CMA,INA 2'S COMP. STA COUNT LDB DAB. SETUP BUFFER ADDRESS STC SCT,C T2 LDA B,I GET A CHARACTER OTA SCT PUT IT IN THE FIFO BUFFER INB ISZ COUNT INCREMENT COUNT,COUNT=64? JMP T2 NO GET NEXT CHAR!!! LDA CW5 YES,LOAD W TO CLEAR BUFF OTA SCT HALF FULL STC SCT,C SET CONTROL,START TRANSMIT SFS SCT IS BUFFER EMPTY? JMP *-1 NO,CONTINUE SENDING HLT 02 YES, IT IS EMPTY,HALT CPU!! JMP START RESTART 12966 END --- cut here --- -Frank McConnell

25 years, 11 months

Tim's own version of the Catweasel/Compaticard/whatever

by CLASSICCMP＠trailing-edge.com

>>2. The Catweasel uses a proprietary, largely undocumented programming >>interface. My circuitry is entirely open, and I think it's pretty easy >>to program. (My first hack at acquiring data with the new buffer was >>dashed off in about half an hour under QBASIC.) >Thier doc's pretty much stink, or at least did when I got mine! It sounds like John Wilson has reverse-engineered at least *some* of their programming interface, though last I heard there were parts of the interface that were a mystery even to him :-). >>Would it be worth writing up my new floppy disk data buffer so that >>others could improve on it? Would anyone be interested in unstuffed and/or >>stuffed PCB's? Should I give it a name? (The "Timweasel", anyone? I >>gotta think of a better name!) >Maybe/probably. It looks like my circuit can be put on roughly a 3" x 4" PCB, meaning that after paying for ExpressPCB overhead it'll be maybe $20 or so per PCB in small quantities. The PCB would have a 24-pin header for interfacing to a PC-clone parallel port (or whatever cabling you want to any other sort of parallel type port on another hardware platform), and 34-pin and 50-pin headers to hook to 3.5", 5.25", and 8" disk drives. I haven't priced the chip costs, but they'll probably total around $25 or so from a hobby place like Jameco or from a real distributor like Digi-Key. Chip lineup in my current design: 1 62C1024 128K*8 SRAM. 1 74HCT373 for latching control signals from parallel port, 3 of the outputs are used to drive the head load and step/direction lines to the floppy drive. 8 MHz crystal clock. 1 74HCT74 for bi-phase clock generation and pulse synchronization from the floppy read line 2 74HCT175's to make a seven-stage ring counter. Only 3 phase outputs are used, one to latch and increment the counters, one to latch the outputs of the shift register, and one to do the write enable. 1 74HCT164 for taking serial data from the 74HCT74 pulse synchronizer and turning it into 7-bit wide parallel out. (The 8th bit comes from the index line). 1 74HCT374 for latching the shift register data and tri-stating it onto the memory buffer bus. 1 74HCT04 and 1 74HCT00 for gating and inverting as necessary 2 74HCT590's and 1 74HCT93 for making a 20-bit buffer address counter. (17 bits are used in the current implementation, though we obviously could just drop in a bigger SRAM and use the extra address bits.) I took some pains in my design to allow things to be sped up for more oversampling at a later date. (I'd probably want to replace the 74HCT93 with a third 74HCT590 just to make all the address counters fully synchronous, but I only had 2 HCT590's in my junk box when I built this implementation). The timing from the ring counter and the rest of the HCT logic ought to make sampling up to 40 MHz very straightforward (I'd have to lengthen the write-enable from the ring counter at higher clock speeds to cover a couple of clock phases). > It would be nice to stuff one in a Linux box, or will it >work in an Alpha under VMS :^) Anything with a bidirectional parallel port oughta work fine. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 11 months

Tim's own version of the Catweasel/Compaticard/whatever

by CLASSICCMP＠trailing-edge.com

>The only problem I'd point out is the the 9500 series CPLD's drive only 8 mA >per output and, unless you were planning to pair them up, i.e. use multiple >pins tied together to drive the FD cable, you might have problems. The biggest problem is with the outputs that'll drive the floppy disk bus. Typically it's an open-collector output terminated to +5V with 150 ohms, so you have to be able to sink 30 mA or so. So yes, this may be a concern. (Or you can cheat and tie the lines high with "only" 220 or 300 or 470 ohms - shouldn't be a big problem as long as there's only one drive on the bus.) Do any CPLD's have "real" open-collector outputs, or can you fake it by sending the output into tristate mode? (I'm asking this as a guy who's never designed with CPLD's but does know 74XX00 series logic pretty well.) I don't think it's an issue either way with exactly one controller and one floppy drive on the bus. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 11 months

OT?: failure modes of a RAMDAC

by cem14＠cornell.edu

This is OT in that the piece of hardware that I'm looking at (matrox millenium pci card) is newer than 10 years. On the other hand, any comments on this might be useful for older equipment as well. Here's the scoop: the video card in my home computer suddenly started acting flaky. The image flickers and has diminished brightness; at first I thought that it was the monitor, until I noticed that the area inside the dialog window that pops up when operating the setup menus in the monitor does not flicker and has normal brightness. Aha, cable or connector, I thought. So I tested another monitor. Exact same symptoms on the second monitor. Ok, then a cold solder joint in the card. I extracted the card and had a good look at it. Nothing looks wrong. I put the thing back in and it still had the flickering. Then, all of a sudden, brightness jumps back to normal and everything works fine for the rest of the session. Next day, I power up, and several hours later the symptoms reappear suddenly. I am thinking that the output of the RAMDAC is being severely affected by something that diminishes its swing. As far as I can tell, all colors are affected uniformly. The flicker is random, does not appear to be tied to a given frequency, and seems to affect the whole screen (refresh is currently 85 Hz; changing it does not alleviate the problem). So I wonder if there is some oscillation in the output of the RAMDAC or an internal short that limits the swing or what. Has anyone seen this sort of failure before? carlos.

25 years, 11 months

Friden help

by aw288＠osfn.org

Does anyone on the list have any experience with Friden Automatic Calculators? I have been fooling around with one, and it mostly works, but every few minutes locks up. I am not sure what is causing a problem, as the machine is quite complex. It only locks up when calculating. I am sure it needs a lube job, but at this point all I have done is bathe the whole thing in WD40. When things are going well, I will give it a real lube job. William Donzelli aw288(a)osfn.org

25 years, 11 months

Tim's own version of the Catweasel/Compaticard/whatever

by CLASSICCMP＠trailing-edge.com

Hi folks - The topic of reading or writing older "odd" disk formats (hard-sectored, GCR, whatever) comes up here pretty often. And often the discussion leads towards the Catweasel floppy interface (currently available commercially, as I understand) or the Compaticard interfaces (not currently being manufactured, as I understand). I've recently "modernized" my foreign format disk reading hardware. The idea of both the "old" version and the "new" versions are very similar to each other, and to what other tools like the Catweasel and the Compaticard do: Data from a floppy disk drive comes as a series of pulses on the read data line. All these circuits (using different means) buffer up to an entire track of data in RAM, and then allow a user program to look at the buffer and analyze the data on its own terms. They also allow control over rudimentary floppy functions such as step in/out, load head/start motor, etc. *I* buffer the pulses on the read data line by simply recording a "1" bit if there was a pulse in a window, and a "0" if there wasn't. I sample at 4MHz, meaning that a complete revolution of a floppy requires most a megabit of RAM. I also buffer information such as index pulse data (essential for decoding many hard-sectored floppy formats.) The bit rate from most standard floppy formats is roughly 500 kHz, meaning my 4 MHz sample rate oversamples by a factor of 8 or so. Yes, it's overkill for many applications, but I want to be sure that all information on the floppy is faithfully represented in the buffer. Besides, many GCR and some MFM variants use half- or even third-fundamental-frequency components (sliding the pulse in the window to encode more data without increasing the clock rate) and oversampling is necessary for these formats. Other buffers (I believe the Catweasel falls in this category) record the times between successive pulses in RAM, instead of the "raw bits". My "previous generation" buffer had a megabit of SRAM and interfaced via a 16-bit-in and 16-bit-out parallel interface (usually to a DR11-style interface on a PDP-11). The megabit of SRAM was made up of a whole bunch of 2k*8 SRAMS, meaning that just the buffer memory required a couple of sizable PC boards. (If you're familiar with the technology, you'll get the idea that "previous generation" buffer was based on chips readily available around 15 years ago.) My "new generation" buffer has the same megabit of SRAM - but now in a single SRAM chip - and interfaces via a PC-clone bidirectional parallel port. Other than the big SRAM chip, the rest of the buffer is just eleven SSI and MSI HCTTL IC's. The eleven chips form the PC-side interface, the floppy-side interface, the timing clocks, the buffer sequencer, and the buffer address (17 bits) counters. So how is my buffer different than, for example, the Catweasel? 1. The Catweasel uses some custom LSI parts, as far as I can figure out. My circuit is much more "hackable", anyone with a TTL databook can figure out what it does and improve on it. Or you can build one yourself from scratch. (Other than the 128K*8 SRAM, all the other parts were literally purchased from the local electronics shop. Heck, most of the chips can be bought at Radio Shack!) Total cost for the chips in my buffer is about $30.00, about half of that in the SRAM chip. 2. The Catweasel uses a proprietary, largely undocumented programming interface. My circuitry is entirely open, and I think it's pretty easy to program. (My first hack at acquiring data with the new buffer was dashed off in about half an hour under QBASIC.) 3. The Catweasel requires a bus slot inside a PC-clone. My new buffer uses a much more general purpose parallel interface. So you can hook it up to a laptop, or even to something that isn't a PC-clone at all. Those are what I see as advantages over the Catweasel. There are also some disadvantages: 4. You can't just go out and buy my buffer, but you can buy Catweasels off the shelf. 5. My buffer is strictly "read-only" as I use it. I think the Catweasel (and Compaticard) both allow writing. Would it be worth writing up my new floppy disk data buffer so that others could improve on it? Would anyone be interested in unstuffed and/or stuffed PCB's? Should I give it a name? (The "Timweasel", anyone? I gotta think of a better name!) -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 11 months

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb