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101090 discussions

by henk.gooijen＠hotmail.com

Hello readers, I cleaned the first of my RM03 drives today. The drive is quite clean even after several years of no attention. Just a few spiders webs and tiny dead spiders, and little dust. I picked up this drive in Turin Italy, together with Edward several years ago. I cannot remember doing it, but the head lock pin was in the lock position. After cleaning and a good inspection (I found a small metal bracket piece next to the PSU output plugs, and have not found where it came from!), I mounted a mains power plug to the drive cable. Massbus cable is attached to the drive, the other end is not connected to anything. After setting all circuit breakers ON (two inside the drive, two at the rear side next to the running hours counter), I plugged the mains in and switched mains on. I hear humming of the fans, so it seems OK. However, this is my problem: the door latch stays locked, I cannot open the lid. I want to open the lid to clean the inside of the drive bay. After some reading (EK-RM023-TD-001_RM02_03_Tech_May78.pdf), I found this in chapter 4.4 (page 4-7): The initialize sequence starts with the receipt of a Massbus INIT signal from either port A or B. This sequence is used to condition both the adapter and drive circuits to a known reset state. The functional block diagram for the initialize command is shown in Figure 4-5. The Massbus INIT signal (whether coming from port A or B) clears the AT A bit in the attention summary register in the IF module. In the CS module, it is converted to the MBA clear signal which performs the following: 1. Clears the enable search latch 2. Sets the on latch 3. etc. So, do I understand this correctly that without an initial Massbus INIT signal the lid remains locked? Or has this RM03 drive a "lock issue"? If somebody has an RM03 drive, is it possible to open the lid without Massbus cables hooked to the RH70 or RH11 controller? Is that Massbus connection required + INIT command to unlock the lid? I have not yet cleaned the other two RM03 drives, and I do not want to apply power without cleaning and inspection! So, I cannot check whether all 3 drives keep the lid locked. I forgot to take the camera with me, but I will take pictures! Thanks, - Henk

10 years, 3 months

VAXELN Datagram Service

by robert.jarratt＠ntlworld.com

I am doing a bit of VAXELN programming and I am trying to get the Datagram Service to only read packets of a certain EtherType, but unless I use promiscuous mode, nothing is read. Here is the relevant code: form.format = ELN$K_NI_PTT; form.mux.ptt = 0x0360; mode = 0; pad = 0; eln$ni_connect(&status, &portalId, config.clist.list[i].control_port, &dispatchPort, &form, NULL, &mode, NULL, NULL, NULL, NULL, NULL, &pad); Anyone know why this might not return any packets at all when I wait on the port? Regards Rob

10 years, 3 months

ESR meter recommendations.

by mattislind＠gmail.com

2016-01-23 13:54 GMT+01:00 Noel Chiappa <jnc at mercury.lcs.mit.edu>: > > From: Mattis Lind > > > I don't have an capacitance / ESR meter so I cannot check it. > > If you do a lot of work with analog components (and it sounds like you do), > it's probably worth getting capacitance and ESR meters, they can be > obtained > (new) on eBay for not that much. I have one of each that I got that way; > their quality is pretty good, considering how little I paid for them (I > didn't think I'd be using them enough to make it worth paying out a lot for > really good ones). I haven't used the ESR meter much, but the capacitance > meter works quite well, and has been very helpful. Of course, it can't be > used in-circuit, but... > > Yes. agree with you.I really should get one. I have been thinking I need to get one every time I get my head into anther PSU and then everything is sorted out and the PSU seems to work fine and I forget about it. I have been looking at the DerEE DE-5000 which looks nice and has got good reviews as far as I can tell. What meter do you have and recommend? > Alas, I can't (easily) help with the VT100 question! :-) > That's a pity! > > Noel > /Mattis

10 years, 3 months

C64 system cost?

by starbase89＠gmail.com

Hey, I've been looking into getting a C64 system to play with. I'm looking for not just the computer, but a 1541, a datasette, color monitor, printer, joystick and modem, and some software. Eventually I'd like to get an SD card adapter, too. Can someone give me an idea as to how much I might end up spending on all of this? Thanks! Joe <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> This email has been sent from a virus-free computer protected by Avast. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

10 years, 3 months

IDE knowledge anyone?

by lehmann＠ans-netz.de

Hi, I've built a Harddisk-Controller-Emulator for my system which accesses a IDE (PATA) harddisk with an ATMega in PIO mode. It works like a charm except for one WD harddisk. The harddisk itself works fine with MS-DOS 6.22 and FreeBSD but refuses to work with my ATMega. On reading or writing a sector, right after the command is issued, the error bit is set in the status register, and the error register indicates an ABRT. # ABRT: # indicates the requested command has been aborted due to a # drive status error (such as not ready or write fault) or because # the command is invalid. Right after power up and after the disk got ready, I issue the IDENTIFY command and read the data back which works perfectly. After that I read sector 0 and this fails. I use LBA since the harddisk states that is supportes LBA. Nevertheless I also tried accessing the harddisk with CHS mode and got the same error. I tested other harddisks which support either CHS+LBA or CHS only. All of them work perfectly. What happens after powerup to read block 0 of the disk in LBA mode: - Setup AVR ports and so on - wait until RDY gets high - wait until BSY gets low - issue a Drive/Head register Command with value 0 - wait until BSY gets low - issue a Command Register Command with value 0xEC (identify device) - *read data* - process and print out data - wait until BSY gets low - issue a Sector Count register Command with value 0 - issue a Sector Number register Command with value 0 - issue a Cylinder Low register Command with value 0 - issue a Cylinder High register Command with value 0 - issue a Drive/Head register Command with 0 + 0xE0 (LBA, Drive 0) - issue a Command Register Command with value 0x20 (Read Sector) - *read data* *read data*: - wait until BSY gets low - check ERR bit in the Status register <- set on cmd 0x20 here - wait until DRQ gets high - issue a Data register Command with no data - put /RD on low - read 512 bytes of data - put /RD on high - check ERR bit in the Status register Issuing a Command works always like setting /CS0, /CS1, /DA0, /DA1, /DA2 to low, and then set the needed signals to high so the desired command is indicated. When data has to be transfered with this command, the lower 8 bits are put then onto the port, /WR is set to low afterwards, 3 nop() are done and /WR is set back to high. Does anyone see an error what could make the drive behave like I said? - ATA IDENTIFY works, and the drives data can be read - after a read or write sector command is issued, the status register directly goes 0xd0 (busy) and with the 2nd fetch 0x59 (not busy, drq set, err set) Regards, Oliver

10 years, 3 months

VT100 PSU smelling.

by mattislind＠gmail.com

Short: R27 in my VT100 PSU is hot and smelling. Why? Long: I think it has been 20 years since I powered up this VT100 so I did it carefully. Used a Variac and a bench supply. It switched just fine and delivered the steady 5V out when the input was at approx 50V (115V input). All the other voltages looked fine at full AC input. But there was this little smell from R27. Then I plugged everything in and fired it up. Now there were considerable more heat generated in R27 which is a 13W / 1kOhm power resistor. But I still had 4.99V over a random TTL gate on the logic board so the PSU seemed to operate just fine. R27 is part of the snubber network on the primary side of this forward-type SMPS PSU. But why it it getting so hot. Is it normal? I have completely forgotten how a VT100 smell when running... Anyone out there with a VT100 that can put his or her nose above R27 and tell me the temperature? One interesting thing is that DEC apparently did some kind of ECO since my resistor is 1k while the schematic tell me 500 ohm. It doesn't seems to have been replaced. I checked D27 and that one looked fine. Could there be some marginal problem in the circuit somewhere that cause excessive hearing of R27? The primary side looks fairly simple so there are not many components that could fail completely which wouldn't cause complete death of the PSU. C19 is part of the snubber network and is a 0.0033uF 1600VDC film capacitor. Can these go marginal somehow? I never heard of that but maybe? /Mattis

10 years, 3 months

SD Card disk drive for C-64?

by tulsamike3434＠gmail.com

On 01/23/2016 07:48 PM, Mike Boyle wrote: > > > On Sat, Jan 23, 2016 at 7:28 PM, Eric Christopherson > <echristopherson at gmail.com <mailto:echristopherson at gmail.com>> wrote: > > On Sat, Jan 23, 2016, Jim Brain wrote: > > On 1/23/2016 2:18 PM, drlegendre . wrote: > > >First off, my bad - I thought the OP was wanting to change the > device ID > > >(which is not the drive number, btw**) on a genuine 1541. I'd > have no idea > > >how it's done with one of the SD-based drive emulators. > > Google is still a friend: > > > > > https://www.google.com/search?q=sd2iec+change+device+numbers&ie=utf-8&oe=ut… > > > > There are no external switches on some of these drives. > > > > But, the BASIC commands used to switch device numbers on the > 1541 also work > > on these units, and putting an extra char at the end of the > command will > > make the changes permanent, as I recall. > > > > Jim > > Jim, don't you sell a device that's useful for temporarily > switching off > specific drives so the device numbers can be changed more easily? > > -- > Eric Christopherson > > > > > -- So I guess the question now is should I change the sd drive or the original floppy? Thank you all for all the wonderful help god bless you all! > * > Mike's ? > Honda ATC 3wheeler > ? Shop? > for LIFE!!!* > * > Have a blessed day!*

10 years, 3 months

Character ROMs for HP 2631G printer / 264x terminals

by curiousmarc3＠gmail.com

I just resurrected a nice HP 2631G dot matrix line printer: Like here: http://www.hpmuseum.net/display_item.php?hw=316 It has 3 empty slots for extra character ROMs, so I am itching to install some... Anyone has ever made a dump of these character ROMs? Apparently these are the same as the extra character sets ROMs used in the 264x terminal. Math, Line Draw and Japanese would be particularly fun... And French too as a nod to my roots. Marc

10 years, 3 months

ESR meter recommendations.

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > What meter do you have and recommend? My capacitance meter is a Uyigao UA6013L, and I'm quite happy with it; it seems pretty reasonable build-quality. A number of people on eBay are selling them, IIRC. My ESR meter is, alas, literall nameless - I looked on both the meter, and the (single-sheet) documentation, and there's no name anywhere. (Yes, yes, I know, I got what I paid for - which was not much! :-) Noel

10 years, 3 months

Introduction and RK05J Drive cabling

by jnc＠mercury.lcs.mit.edu

> From: Guy Sotomayor > To that end, I've made new "paddle" board that take 2 60pin ribbon > cables. Guy, this is fantastic news! I have previously speculated about doing this, but it's still on the 'someday' list. > I'll let folks know how they turn out (ie do they actually work!). They should. DEC made the same basic part, but using 3x40-pin cables: M9042 (half-length, knuckle-buster) and M9014 (full-length). Apparently the characteristic impedance of N-pin flat cable is close enough to the BC11 cable that it works. Speaking of M9014's, though, the board list describes them as "UNIBUS to 3 H854s", and also lists an M9015, described as "3 H854s to UNIBUS". Does anyone know what the difference is between the two? Unlike the QBUS, the UNIBUS shouldn't need two different kinds of board, since the 'grant in' pin on one end of a UNIBUS cable is the same as the 'grant out' pin on the other end (unlike the QBUS, where the pinout is designed to support plugging in boards, so there are separate 'grant in' and 'grant out' pins). I can't for the life of me think of anything about the UNIBUS that a straight through-connect wouldn't handle - i.e. a pair of M9014's, on each end of the cable set. Certainly, BC11 cables ends aren't marked 'in' and 'out'! ;-) So does anyone know why the M9015 exists - what it different about it, etc, etc? Or was someone at DEC just not thinking hard enough when they spec'd it? > The downside is that they were somewhat expensive Heh, they'll still be cheaper than actual BC11's! :-) Noel

10 years, 3 months

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