test-drb April 2002

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cartridges

by md10＠wanadoo.fr

Skipped content of type multipart/alternative

24 years

TTL computing

by csmith＠amdocs.com

> -----Original Message----- > From: Roger Merchberger [mailto:zmerch@30below.com] > If you actually put sockets on the board and insert the fuses > into that, > you could simulate an EPROM/Flash[like] part. ;-) It'd take a while to > "erase & re-write", but hey... ;-) Exactly what I wanted to do. I thought about setting them flat against a board and using the small (half-inch long) "glass tube" inline fuses. If I can get those to smoke the glass dramatically enough when they blow, it would be easy to replace the blown parts with fresh fuses for a new program. Not to mention that it may be fun to be able to re-arrange the fuses ;) Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '

24 years

Half on, half off -- New CD-R drive and 512-byte blocks

by ajp166＠bellatlantic.net

I've used a plextor plexwriter, toshiba 2x, some noname ($29.95 new!) scsi successfully. The cdrom,(hobbiest) does however not boot on any of them, though the standalone backup does and that is used to copy the images to a small RZ25 for actual running. Allison -----Original Message----- From: Alexander Schreiber <als(a)thangorodrim.de> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Wednesday, April 10, 2002 10:17 PM Subject: Re: Half on, half off -- New CD-R drive and 512-byte blocks >On Tue, Apr 09, 2002 at 04:27:50PM -0500, Dan Wright wrote: >> I do know, from experience, that any SCSI Plextor CDROM/CD-R/CD-RW will boot >> basically anything -- Sparc, SGI, RS/6000, HP,.... I've tried plextors of >> varying ages (old 8plex caddy-loader up to a 12/4/32 CD-RW that's about 1 year >> old) and they all work great... > >In this case, I've got bad news or you. You might be out of luck trying >this with a VAXstation 3100. My VAXstation 3100 started to boot the VMS 7.1 >install CD, but barfed halfway through loading the kernel. I was not >happy with either the 4x, the 8x or the 12 SCSI Plextor, nor with the >Toshiba drive (all set to 512 byte/sector). Ripping a DEC RRD42 out of >one of my DECstations finally did the trick. Seems like this machines >are rather ... touchy about what they boot from. > >Regards, > Alex. >-- >We're gonna be body guards for teen rock-stars. Wouldn't the cause of freedom >be better served if we killed them instead? > -- Schlock from the ''Schlock Mercenary'' comic strip >

24 years

Half on, half off -- New CD-R drive and 512-byte blocks

by csmith＠amdocs.com

Hi everybody. This isn't strictly on topic, but I think the intent of the question makes it close enough. I just bought a new CD-RW drive -- a Sony CRX145s -- and am curious about whether it may read the 512-byte blocks necessary for using it as a backup boot device on my VAXen, Sparc, SGI, etc. Does anyone know whether this, or just for information, some other CD-RW unit, will do such a thing? Note that I do know that discs are written in 2048 byte blocks, and the answer won't affect its performance in writing disks on these systems. I am also aware that doing this for the long term may needlessly shorten the life of the drive. As I said above, it is more for curiosity, and eventually I would like to know that in case my RRD42 dies, I have a backup. :) Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '

24 years

TTL computing

by IVIE＠cc.usu.edu

Thilo Schmidt wrote: > The Address of the ROM is the current-state (lets say the line-number > of the programm). Every line of Code consists only of the "outputs" and > one or more "next states". The "inputs" select which "line" comes > next: Either the next "line" of Code (that's what the counter is for), > or one of the "next states". I made a mistake there, the Microcoded Machine > has to look like that: > > |---|---> OUT > address | R |---> > |-->| O |---> |--[Counter] > | | M |----| | > | |___| \MUX/<--- IN > | | > |-[StateReg]<-- Actually, there are a grundle of ways to do this. Here's a scheme that doesn't require a counter, but requires wider microcode: > |---|---> OUT > address | R |---> > |-->| O |---> > | | M |------| > | | |----| | > | |___| \MUX/<--- IN > | | > |-[StateReg]<-- In this case, each microcode word contains two addresses: one for when the input is true and one for when the input is false. If you want to go to the "next" word, the appropriate field in the microcode contains the current address +1. And then there's: > |---|---> OUT > IN ---->| |---> > address | R |---> > |-->| O |---> > | | M |-----| > | |___| | > | | > |-[StateReg]<-- This does away with the mux by using the input as one of the address bits. It doesn't get more simple than this. You used to be able to get registered EPROMs; using those, the state and output registers are built into the EPROM and all you have to do is wire it up. And write a grundle of microcode, of course... The Firefox QBUS Adapter was implemented this way. Some of the outputs ran back around to control a mux to select which input was being examined by the microcode for a given state. Hmm, I'm going to have to turn your drawing sideways, I think: > INPUTS > ||| > ||| > VVV > +----------->\MUX/ > |+-------+ | > || | | > || V V > || +--------------+ > || | ROM | > || +--------------+ > || | ||| > || V VVV > || [State and Output reg] > || | ||| > |+--------+ ||| > +----------------+|| > || > VV > OUTPUTS Since this was done using registered PROMs, the only parts are ROMs and the mux. And a synchro register for inputs; I don't recall whether I synchronized the inputs before or after the mux. Am I the only person who sees registered SRAMs intended for cache and things "Hey! A huge microcode store that can run really fast!"? Some of them even have JTAG inputs you could use to load the microcode. Fundamentally, a state machine consists of inputs, outputs, a state register, and a next state decoder. A microcoded system just uses a ROM for the next state decoder. Roger Ivie ivie(a)cc.usu.edu

24 years

New MV-II boots! And, of course, Questions....

by doc＠mdrconsult.com

I'm quite tickled. Also inordinately proud of myself (for figuring out the BA23's slightly different connections & stuff and not letting loose any Magic Smoke). First thing: Thanks, Terry! I really like it. Terry's rackmount MicroVAX II has been condensed into a single BA23. For the nonce, I'm running a single RD54 and a TK50 on their respective controllers, and a DELQA ethernet board. The KA655-A with 32M is a LOT faster than the KA630 with 13M. The TK50 is slow as ever.... I was hoping the BA23 would be quieter than the BA123. It's not. Questions: Does the KA655 CPU make this a MV-3800, a MV-III, or a MV-II with a KA655? Terry, looks like you were right: The memory board, which is a DataRAM 63016 C0. Listed online as a 16M board some places and 32M others. The system sees it as 2 16M boards. Is this kosher? The 3-position CPU-RAM ribbon cable is plugged at one end and at the middle connector. Does it matter? I'd _really_ like to run the RX50 instead of the TK50. Unfortunately, I don't have a cable. Can a PC floppy cable be modified to work? It looks like, from reading past posts, connecting on the "B" connector - i.e. no twist - ought to do the trick. Not quite brave enough to just plug it in and see. Last (not really applicable in the BA23), I see references to terminating the last RD5x on an RQDX3. Is that termination effected at the distribution board (M9058 in the BA123) or on the drive? Drive 1 and Drive 2 don't look any different. Which may be why they're, um, terminally off-line. Doc P.S. - I've always wanted to say "For the nonce"....

24 years

VAX 11/750 Power

by Antonio.Carlini＠riverstonenet.com

>Hello all, I would be extremely grateful if those of you with VAX >11/750s out there could either take pictures or draw diagrams of how the >PSU blocks are connected in this wonderful system. You have the printsets. You'll find that in addition to the schematics, they also include (almost) enough information to build the PSU from scratch. If you have The Installation Manual (there are several, two of which you can find at http://208.190.133.204/decimages/moremanuals.htm ... except it's still down...) specifically EK-SI75F-IN-001 has some pictures on pp1-18, 2-1 The printset is probably a better guide! >I have (finally) received my first piece of Big Iron but it has death of >the 2.5v PSU, and all the PSU bricks were removed and handed to me >before I could note their positions. Oddly enough, the last one I saw had exactly the same problem. The 2.5V PSU was not regulating properly. >Also, if any of you have a terminal >going spare (vt or hardcopy, either >ist gut) then shout out and we can talk... I don't have one spare, but people who do might want you to pin down your location a little ... Antonio

24 years

Decitek 262 info wanted...

by jos.mar＠bluewin.ch

I obtained a cheap (10 USD) Decitek papertape reader from Ebay. ( A tip for those who believe that to be impossible : try .de instead of .com ) However it has a seemingly exploded IC on it : IC "I" below R5 and R4, has had it top half blown off..... Anybody with a similar reader could look up what kind of IC it was ? And if anyone has the pinning for this reader handy... I just saw that Decitek still exists. Do they react kindly to hobbyists ? Jos Dreesen

24 years

TTL computing

by ajp166＠bellatlantic.net

some items sorta conspired to drive cpus to multiples of 8bits. ASCII chars width of data paths internal to MOS cpus early on. byte wide memories, especially rom/prom/eprom Personally I like either 18 ot 24 bits and have thought that the PDP-8 with the right side (address portion) of the word stretched to 18 bits or better yet 24 would be a nice machine. 24bits is majik as it's a multiple of 8. PDP-8 addressing as 24bit 524288 word page, current and also there is page 0 addressing! A field would be 16MB. EMA would not be needed. Allison -----Original Message----- From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Wednesday, April 10, 2002 11:21 AM Subject: Re: TTL computing >Richard Erlacher wrote: > >> 12-bit CPU's out there ??? Everybody knows that 12-bitters haven't existed >> since the '70's! After all, they stop existing on the day the last one is >> shipped. The device manufacturers stop considering a market as viable once >> the potential for 100K pieces per week per manufacturer is no longer there. > >True about manufacturing, but I wish one had more choice with computer >hardware/software for the PC user.I think DEC sold the PDP-8 until about >1990. Since I can't find a 12/24 bit CPU that I like I am building my >own. A 12/24 bit cpu chip could have came out around 1980 with the >8086/6800. Part of the challenge in the cpu design I am doing in FPGA is >to have it emulate (for the most part) a fictional 12/24 bit cpu in a 40 >pin dip.The last thing I added was a 8 bit refresh counter for dynamic >memory and a single channel DMA for a floppy. Running at 4.9152 Mhz ( >800 ns memory access, 512Kb of ram ) I hope the Squash the XT market in >1983!. :) > >-- >Ben Franchuk - Dawn * 12/24 bit cpu * >www.jetnet.ab.ca/users/bfranchuk/index.html >

24 years

Twinax (was Re: Last run at the local Uni Surplus for a while ...)

by csmith＠amdocs.com

> -----Original Message----- > From: Ethan Dicks [mailto:erd_6502@yahoo.com] > I do happen to have some twinax baluns from a former tenant of a > shop that my former employer took over. They previous guys > had an AS/400 > and terminals on peoples' desks. The best computer in the place was a > 486 tower, in 2000! They were in the forklift business - Wait -- if I understand you properly, they had an AS/400, but the best computer was a 486? I'm missing something here, and I'm certain to be near enlightenment when I figure it out... Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '

24 years

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test-drb April 2002