test-drb January 2008

test-drb@ccmp.vtda.org

221 participants
430 discussions

inexpensive prototype boards with 22/44 pin edge connector

by lynchaj＠yahoo.com

Hi, Does anyone know where to get some inexpensive prototype boards with the 22/44 pin edge connectors? I am looking for something like DATAK or VELLEMAN boards preferably under $10 a piece. I have looked but have not been able to find any. Any hints would be much appreciated. Thank you in advance! Andrew Lynch

17 years, 3 months

SEL -> Gould

by aek＠bitsavers.org

'82-ish http://www.paralogos.com/DeadSuper/Misc/Gould.html The Powernode was a 32 bit machine that had pretty decent I/O performance for the time. Some docs came along with the shipment from Germany (no machine though..) Have it scanned, will try to get it up on bitsavers.

17 years, 3 months

CROMEMCO: The "Cro'sNest" lives!

by rckuhmann＠charter.net

All: Re: CROMEMCO Looking for all manner of Cromemco (S100) items ...to buy or as contributions -- docs & manuals (paper or PDF), software & hardware. http://www.kuhmann.com/Cromemco/CrosNest.htm The above is my Silicon Valley memoir -- the long-time Sysop of the the "Cro'sNest RCPM-RBBS" 1977-1997 (formerly of Hayward CA & Sunnyvale CA, and France). Regards, Robert P.S. I have an implementation of MICAH CP/M 2.2 for the Z-2D (uses 16FDC). Seemed I saw someone was looking for that... P.P.S. My archives contain: S100, CP/M, CROMIX, Cromemo, uProcessor info, etc. -- all is on DVD's, e.g. (S100 2.0Gigs, Cromemco 4.3Gigs, CP/M 1.2Gigs, Vintage 3.54Gigs). Robert C. Kuhmann Delavan, WI USA

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by dm561＠torfree.net

-------------Original Message: Date: Sat, 12 Jan 2008 09:37:06 -0800 From: "Chuck Guzis" <cclist at sydex.com> Subject: Re: Creating new CP/M disks - Progress on IMSAI > Date: Fri, 11 Jan 2008 23:50:27 -0500 > From: "Richard A. Cini" <rcini at optonline.net> > Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb > high-density; no schematic) drives Im using is that the motor runs all of > the time (just like an 8 drive) but these late-model Teac drives dont > have head relays, so the heads are engaged all of the time. Since the 8272/765 does drive "polling", you have to connect DRIVE SELECT/ to DRIVE SELECT/. Connecting it to MOTOR ON/ would likely have some odd effects. Recall also, that the 765 can do overlapped seeks on multiple drives, which requires that the DRIVE SELECT/ line be what it says it is. Which leaves you with connecting HEAD LOAD/ to MOTOR ON/; not a good solution if you do a lot of multiple-drive operation (as CP/M floppy systems are wont to do). Better would be to use a timer to monitor the HEAD LOAD/ line and keep MOTOR ON/ active for a minute or so after the last drive activity. A (or a couple) of NE555's should do the trick. Recall that with the 55GFR, as the drive will not gate INDEX/ pulses until it's determined that the diskette's come up to speed. (This, BTW, is why hard-sector diskettes don't work in a 55GFR). So if you'r getting INDEX/ pulses, the drive, by definition, is ready. That's not to say that you couldn't get a GFR with a head-load solenoid, but they're pretty uncommon. My take anyway. Cheers, Chuck ----------------Reply: That was going to be my last-ditch suggestion for the TEAC, putting a one-shot delay on the /MOTOR ON line (Chuck, you know how I love 555s ;-). That delay on the 55GFR is not only a problem with hard-sector diskettes; when I went through this exercise replacing 8" drives on my Cromemcos (soft-sector), the GFR didn't work because the /DS -> /READY delay was too long, even with the motor spinning. Tying /READY to ground made it work and I suppose one could tie /READY to /DS with a diode if one had no other drives available. Interestingly, Andrew Lynch apparently got a different version of the GFR (-149 IIRC) to work on his Vector with HS disks, whereas my -159 never goes ready at all with HS disks. The YE YD-380 does have a HL solenoid but AFAIK it's not separately controllable; there's a pair of jumpers (HM & HS) that select whether the head loads on /MOTOR ON or /DS. Nevertheless, it's probably the closest to an 8" drive with a HL solenoid and constantly running motor. One thing I've learned from trying to use 1.2Mb HD drives in anything other than an AT is that among the dozen or so drives I tested there's almost no consistency at all as far as jumper options and labelling, /READY and /INDEX logic, etc. are concerned, even with different versions of the same make and model. One of the most adaptable drive in my limited experience has actually been the Panasonic JU-475 FWIW. mike

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by ajp166＠bellatlantic.net

> >Subject: Re: Creating new CP/M disks - Progress on IMSAI > From: M H Stein <dm561 at torfree.net> > Date: Sat, 12 Jan 2008 12:53:13 -0500 > To: "'cctech at classiccmp.org'" <cctech at classiccmp.org> > >Date: Sat, 12 Jan 2008 09:23:02 -0500 >From: "Richard A. Cini" <rcini at optonline.net> >Subject: Re: Creating new CP/M disks - Progress on IMSAI > >>> As a matter of fact, the motor did run constantly on many 8" drives (remember >>> that many had 110V AC motors). >>> >>> m > >>Yes, but the heads engaged and disengaged to reduce wear. On modern drives, >>the heads remain engaged but the motor stops. > >--------- >Exactly; that's why you're having problems. But A & A seem to think there's >something wrong with /MOTOR ON being on constantly, which can be quite >normal on an 8" FDC. Some FDCs do have an option to latch it ON with pin 16 >and turn it OFF with pin 4 BTW. > Yes and when two sided drives were introduced the problem then was when the head were lowered they could "clap" the media can sometimes bite it. Two sided was a new set of problems. In the 5.25"world motors were a problem as they were DC brush motors that would wear both the brushes and the bearings (belt drive). Later drives like the FD55s have a direct drive DC brushless motor that has none of those problems. Anyone ever guess at how long the media lasts with the motor turning and head loaded in a clean environment? Months. Allison >m >

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by ajp166＠bellatlantic.net

> >Subject: Re: Creating new CP/M disks - Progress on IMSAI > From: M H Stein <dm561 at torfree.net> > Date: Sat, 12 Jan 2008 12:53:45 -0500 > To: "'cctech at classiccmp.org'" <cctech at classiccmp.org> > >-----------Original Message: > >Date: Sat, 12 Jan 2008 09:47:58 -0500 >From: "Richard A. Cini" <rcini at optonline.net> >Subject: Re: Creating new CP/M disks - Progress on IMSAI > >It must have been a fluke...I can't get the YE drive to operate reliably >either. The drive won't recal consistently. I might try lengthening the HL >time in software and then give it another shot. FYI if the drive is at track 79... you MUST issue recal twice as the 765 only issues 77 steps MAX to recal. So if you get a recal fail do it again and see if it works the second time (I bet it will). Also if the step rate is 3MS set the 765 for 4ms. Some of the floppies need a 6ms step rate and if stepped faster they will miss a step (or many). There are three controls in the 765 HLT (wait for head load) for those drives that load heads and to let the carriage settle, step rate and head unload time (rarely important). This is set with the Specify command. Allison >I may have to have to stick with the Teac drive and figure out a way to >control the heads by software. > >----------Reply: > >If you're talking about a YE Data YD-380 (no suffix; the -B and -C are >completely different drives), AFAIK it does not have the normal DC/RY >option. Instead, it has an RY jumper with no pins provided which, when >jumpered, puts out /READY on pin 4! > >mike

17 years, 3 months

SEL advert

by aek＠bitsavers.org

>> We have quite a bit of SEL documentation in the Computer History Museum >> archives. > > SEL as Standard Elektrik Lorenz? System Engineering Laboratories mini/supermini manufacturer

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by dm561＠torfree.net

-----------Original Message: Date: Sat, 12 Jan 2008 09:47:58 -0500 From: "Richard A. Cini" <rcini at optonline.net> Subject: Re: Creating new CP/M disks - Progress on IMSAI It must have been a fluke...I can't get the YE drive to operate reliably either. The drive won't recal consistently. I might try lengthening the HL time in software and then give it another shot. I may have to have to stick with the Teac drive and figure out a way to control the heads by software. ----------Reply: If you're talking about a YE Data YD-380 (no suffix; the -B and -C are completely different drives), AFAIK it does not have the normal DC/RY option. Instead, it has an RY jumper with no pins provided which, when jumpered, puts out /READY on pin 4! mike

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by dm561＠torfree.net

Date: Sat, 12 Jan 2008 09:23:02 -0500 From: "Richard A. Cini" <rcini at optonline.net> Subject: Re: Creating new CP/M disks - Progress on IMSAI >> As a matter of fact, the motor did run constantly on many 8" drives (remember >> that many had 110V AC motors). >> >> m >Yes, but the heads engaged and disengaged to reduce wear. On modern drives, >the heads remain engaged but the motor stops. --------- Exactly; that's why you're having problems. But A & A seem to think there's something wrong with /MOTOR ON being on constantly, which can be quite normal on an 8" FDC. Some FDCs do have an option to latch it ON with pin 16 and turn it OFF with pin 4 BTW. m

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by cclist＠sydex.com

> Date: Fri, 11 Jan 2008 23:50:27 -0500 > From: "Richard A. Cini" <rcini at optonline.net> > Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb > high-density; no schematic) drives Im using is that the motor runs all of > the time (just like an 8 drive) but these late-model Teac drives dont > have head relays, so the heads are engaged all of the time. Since the 8272/765 does drive "polling", you have to connect DRIVE SELECT/ to DRIVE SELECT/. Connecting it to MOTOR ON/ would likely have some odd effects. Recall also, that the 765 can do overlapped seeks on multiple drives, which requires that the DRIVE SELECT/ line be what it says it is. Which leaves you with connecting HEAD LOAD/ to MOTOR ON/; not a good solution if you do a lot of multiple-drive operation (as CP/M floppy systems are wont to do). Better would be to use a timer to monitor the HEAD LOAD/ line and keep MOTOR ON/ active for a minute or so after the last drive activity. A (or a couple) of NE555's should do the trick. Recall that with the 55GFR, as the drive will not gate INDEX/ pulses until it's determined that the diskette's come up to speed. (This, BTW, is why hard-sector diskettes don't work in a 55GFR). So if you'r getting INDEX/ pulses, the drive, by definition, is ready. That's not to say that you couldn't get a GFR with a head-load solenoid, but they're pretty uncommon. My take anyway. Cheers, Chuck Cheers, Chuck

17 years, 3 months

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test-drb January 2008