test-drb

test-drb@ccmp.vtda.org

101090 discussions

govliq: LG01 DEC printer (San Antonio, TX)

by dj.taylor＠starpower.net

At 09:49 PM 4/15/2007, you wrote: >>Has anyone here successfully bid on and received anything from >>govliquidation.com? Their site has every bit the ease-of-use I'd >>expect from a government facility. The purchase and shipping process >>looks equally intimidating. > >I purchased a number of IBM 2316 disk packs mentioned on the list a >couple of months back. I am VERY HAPPY I drove to Norfolk to pick them >up. > >Those lazy assholes driving the forklifts could not be bothered to >actually LIFT the pallets off the floor when moving them - they just >pushed them along the uneven warehouse floors. I was seen running >across the warehouse when I saw one of the priceless packs bouncing >and skittering almost off the pallet. While this was happening, one of >the shippers had no problems about putting one loaded pallet on top of >another and shrinkwrapping it, all to a delightful sound of crushing >metal and cracking plastic. > >-- >Will I also purchased something from Norfolk, the experience was good. I was happy to get an expensive piece of laboratory equipment for $50. However, the whole process is not set up for the middle-aged amateur electronics hobbyist. I purchased a laboratory spectrometer that I picked up myself. The auction description said it weighed 350 lbs, I thought I could deal with that. It turned out that it wasn't lbs, it was kg!!!! I had rented a minivan to haul this home, but I remember standing outside the warehouse in the cold and mud wondering how in the hell I was going to get this thing in the minivan, and if I did how was I going to get it out once I got home.... The crew at the warehouse was not willing to help, they were pretty worthless. They were there to run the fork lifts to load the bulk lots onto tractor trailers that were coming to pick up. There was one fellow there who was a shipper who helped though, he pointed out the asian fellow who ran the warehouse and he was willing to come out and use the fork lift and some muscle to help me get the instrument into the minivan. I was very relieved. The spectrometer is still on my car port, it will take some doing to get it in the house. [Ramps, pulleys, dolleys, etc - lots of physics - simple machines] I was impressed with the efficiency of the paperwork handling, very well organized. Doug

19 years, 2 months

Mac SE?

by trag＠io.com

>Date: Sun, 15 Apr 2007 17:57:13 +0200 >From: Joost van de Griek <jvdg at sparcpark.net> >On 4/15/07 5:39 PM, Chuck Guzis wrote: > >> One of the Freecyclers here is having no luck giving away a Mac SE >> (not the SE/30). Is this considered to be a collectible? With an >> 8MHz 68000 and 1 MB of memory, I can't see that it'd actually be >> useful for a lot these days. > >SE's are plentiful and I wouldn't consider them collectible. They're also >uglier than the Mac 128K/512K/Plus, while lacking the SE/30's "incredible >power in a small package" appeal (SE/30's make great servers when packed >with RAM and *BSD). > >Unless you "gotta catch 'em all" or you want a compact Mac to play around >with and there are no other models to be found, skip it. However, except for the logic board, the SE is compatible/identical with the SE/30. So, if you need parts for your SE/30, or have a good SE/30 logic board and need a chassis, then a Mac SE is an excellent and usually affordable sacrificial victim. The one caveat to the above is that the first revision SEs came with an 800K floppy drive while later models came with the 1.44 MB "superdrive" and the SE/30s all came with the 1.44 MB floppy. So some early SEs' chassis will differ from an SE/30 in the floppy drive. Oh, and an aside which some may find useful. Most SE/30s have leaking electrolytic capacitors by this time. So if one does decide to collect an SE/30 (or if one has one sitting unused) it would be a prudent move to desolder the SM electrolytic caps, clean the motherboard, and install tantalum caps in their place. Many SE/30s no longer have working sound or simply fail to boot up at all because of leaking caps. Left untended the goo from the caps will/can disolve important traces, pads, solder or pins on the logic board. Jeff Walther

19 years, 2 months

Hawk on eBay

by Billy.Pettit＠wdc.com

Out on eBay, a cabinet mount Hawk disk drive. This is the 5MB cartridge/ 5MB fixed disk used by so many OEMS, especially in the early 70's. The parts alone could be worth picking up if you are trying to keep one of these drives going. Billy 270110421676

19 years, 2 months

Hawk on eBay

by aek＠bitsavers.org

I bid on it the first time. He canceled the auction because the pics weren't supersizing. It's close enough to relatives I'll ask him to deliver it there (it's in Madison)

19 years, 2 months

xt/370 e-mail problem and stacked memory chips illustrated

by Billy.Pettit＠wdc.com

Al Kossow wrote: CHM has an Amdahl 470 and a Siemens 4004 (RCA Spectra). There were lots of people who built byte-oriented machines with instruction sets similar to the 360 and I know there are people who have Interdata, and Univac 9x00 machines. Memorex built a 16 bit 360 like machine, and I have some docs and software for that. The artifacts of these sorts of machines haven't been preserved very well. Same for Burroughs, Univac and NCR (business as opposed to scientific computers). ---------- Billy: Anything in the Museum on the CDC Omega series? These were true IBM 360/370 campatibles, ran IBM software. And of course there are the infamous systems >from Hitachi that actually worked on stolen microcode from IBM. Billy

19 years, 2 months

Classic Computing in Nevada?

by stimpy.u.idiot＠gmail.com

Somewhat reluctantly, I'll be in Las Vegas most of next week. Are there any on-topic sights to see within, say, 1/2 days drive? I'm guessing probably not, but you never know... -- Pete Edwards "Prediction is very difficult, especially if it's about the future" - Niels Bohr

19 years, 2 months

Sydex have some Microsolutions Compaticards for sale (maybe)

by john_a_s2004＠hotmail.com

Hi, I've been reading various threads in the archives about reading and writing to old floppy disks, and the Compaticard has been metioned a few times. I read the following on www.sydex.com: " We do floppy conversion (diskette conversion), we can copy any diskette. We have special hardware for reading non-PC floppies. We are the authors of 22Disk, 22Nice, CopyQM and TeleDisk. We still have a few CompatiCard controllers for sale--please inquire about them. We can supply 5.25 inch and 8 inch drives. If it's on diskette, we can handle it. " Personally I am still thinking about buying a Catweasel card, but am unsure about software for reading and writing hard-sector floppies. I have a Northstar Advantage and am happy to make copies of the system disks (for cost of disks and postage), this uses 10-sector floppies. I also have a AES Superplus IV which is a WP system that uses 16-sector floppies, however the system doesn't allow copies of disks to be be made so once my disk fails / wears out that's it. Having some means to copy disks and store an image file for posterity would be nice, but I am eyeing up the AES for spare parts so wouldn't be sad to give up on trying to copy the system disks (there only seem to be a handful of these systems out there so no great loss there I think). There are plenty of Northstar Advantage owners around, and as long as just one system is working then there is a means of copying floppies for the next guy. Regards, John _________________________________________________________________ Could you be the guest MSN Movies presenter? Click Here to Audition http://www.lightscameraaudition.co.uk

19 years, 2 months

Linux question

by dm561＠torfree.net

A simple question for the Linux gurus from a WIN/DOS simpleton: How do you concatenate two binary files into one? m

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by entity＠nenevr.demon.co.uk

Hello, all. Does anyone on the list know if anyone in our extended community has ever come up with some sort of plug-compatible flash memory replacement for MFM drives? I've a vague idea that I've seen a commercial offering at some point in the past, but obviously that'd be a fairly expensive move to make. (Fairly? Oh, OK. Very.) I've got a Northstar Horizon that I mentioned on here many, many years ago and I've just started looking at it again; once I've got it up and running it'd be nice to add some sort of permanent storage, but without jettisoning one of the floppy drives. The SuperIO board is one option, but I'd like to keep it as stock-Northstar as I can. Anyway, I'd be interested to hear any thoughts on the topic! Cheers, Simon.

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by ajp166＠bellatlantic.net

> >Subject: Re: MFMulation? (Solid-state replacements for MFM drives) > From: Jules Richardson <julesrichardsonuk at yahoo.co.uk> > Date: Mon, 16 Apr 2007 06:56:56 -0500 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Chuck Guzis wrote: >> On 15 Apr 2007 at 19:36, David Comley wrote: >> >>> Exactly. My intended uses are primarily VAX/VMS-based. >> >> Since, as in floppies, you're dealing with raw (unseparated ) data at >> 5MHz or thereabouts, recording bit transitions is out of the >> question. So you'd need some circuitry to both interpret and to >> synthesize not only bits but the various address headers and CRCs. >> IIRC, there wasn't a huge amount of interchangeability between the >> various controller vendors, so you'd need several (selectable) >> routines to handle that. Then there's the matter of RLL and ARLL-- >> and synthesizing CRC or ECC results. > >I'm not sure - remember the task is to emulate a drive, not a controller. >Isn't an MFM ST506/412 drive just a bucket of rotating bits and a track stepper? > >Or does the index pulse function more like that of a hard-sectored floppy - >i.e. the number of sectors per track is fixed in hardware, and there's an >index pulse at the start of each sector? Index is once per revolution. Number of sectors is NOT fixed. One problem is that many of the MFM controllers were into interchangeable. For example a 5mb St506 formatted with my Teltek S100 controller is NOT readable by any WD based controller or for that fact even with a Compupro S100 st506 controller!!! Seems the underlying format (ID, gaps, Sync...) is not standardized at all. Further In the DEC world there were RQDX1/2/3 controllers, the RQDX1/2 were compatable and used the same format as they were the same board (ignoring firmware upgrades and some logic fixes). The RQDX3 however was a differnt animal and required a reformat of the drive (or a specificly RQDX3 formatted replacemen) to use it. In the PC world the WD1003 was a common standard for MFM and the 1005 was a RLL so you alreay had the same drive and two possible formats. Same was true for other systems I'm sure. >Even if that is the case, I wouldn't have thought it makes much difference - >it just means that buffer memory and permanent storage is organised a little >differently. The device is still like a big floppy, just with more heads and >the need to record faster timings between bit transitions: the principle's the >same, it just needs someone with experience of working with fast logic to >design the board layout and code for whatever CPU / DSP is used. There is a notable differnce from say a hard sectord NS* floppy to a 1771 soft sectored TRSdos floppy from a floppy from a system using a 1791. Thats a lot of distance to cover. Sure you can store it as a pattern of bits and it's only possible as ram or some non-moving storage is now cheap. Of course the problem of storage viability over time (longevity of media) is still and issue. Allison

19 years, 2 months

TU56 and TC11 racked

by wacarder＠earthlink.net

Here are some pics of the TU56 and TC11 racked. http://www.woffordwitch.com/TU56projectNum2.asp I would like to hear from anybody who has ever used Dectapes on a PDP-11. This is new territory for me. Ashley

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by ajp166＠bellatlantic.net

> >Subject: MFMulation? (Solid-state replacements for MFM drives) > From: M H Stein <dm561 at torfree.net> > Date: Mon, 16 Apr 2007 03:23:54 -0300 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > >Date: Sun, 15 Apr 2007 23:05:49 +0100 (BST) >From: Entity <entity at nenevr.demon.co.uk> >Subject: MFMulation? (Solid-state replacements for MFM drives) > ><snip> >>I've got a Northstar Horizon that I mentioned on here many, many years >>ago and I've just started looking at it again; once I've got it up and >>running it'd be nice to add some sort of permanent storage, but without >>jettisoning one of the floppy drives. The SuperIO board is one option, >>but I'd like to keep it as stock-Northstar as I can. ><snip> >------------- >If you mean Howard Harte's SuperIO board, apparently he's no longer >making or supporting it; too bad. > >mike Thats also a factor. One I'd point out is the only reason for stock NS* Horizon is NSDos (and related NS* software) as the dos is locked to the disk controller hardware. Once you use another disk interface (ANY) NSDos is a non player and CP/M or one of the similar OSs becomes the choice as you can create your own BIOS to match whatever IO hardware you have. An NS* horizon as a S100 crate is a good system and with a higher density FDC or HDC added and CP/M it has a place as a retro system or as an example of hobbiest systems of the time. It was not uncommon to upgrade a NS* with denser disks or even add a hard disk of some form. For the extreme user, since NSDos is on the net in assembly form it's possible to rewrite it to use a differnt disk or disk equivilent. I've played with that so it can be done. Allison

19 years, 2 months

Fortune 32:16

by jam＠magic.com

> Do you recall anything about how they coded the machine ID to the > software disks. I believe I have some add on programs that have not > been installed. Most though have machine ID numbers written on the > floppy disks. > I have a couple of these machines here one has an bad Motherboard. The copy protection was quite involved. If I recall, all or portions of the software were encrypted using DES, even when it was stored on the hard drive. Each system had a unique PAL device that was used as part of the decryption process so no two systems could share the same encrypted copy of the software. James Markevitch

19 years, 2 months

ST506 WTB:Micropolis 1325

by ajp166＠bellatlantic.net

> >Subject: Re: ST506 WTB:Micropolis 1325 > From: "Andy Piercy" <andy.piercy at gmail.com> > Date: Tue, 10 Apr 2007 00:15:50 +0100 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Alison, thanks for the info, I'll have a go at opening one of the driver, as >currently they are only as much use as a large paper weight! The basic problem is the head arm is stuck to the head park bumper. One temporary fix reported was to freeze the drive rendering the bumper unsticky. Things to know: Never move the heads on the platters if they are not rotating at speed. Never touch platters. Never use magnetic tools near platters (closer than 1"), that means tools that may have remnant magnetism as well. demag them first! You can spin the disk up (just apply power) with the cover off and watch the head load action after bumper fix. Once operational, the first thing I do with the drive is cover it up and put it in a system where I back it up FIRST to another known good drive. Just in case!!! The reason is to a know good drive is faster the copy the less time the drive has if it's going to fail. I had one that failed not for HDA reasons but once the HDA was working I found it would heat up and quit (bad logic board). One last item The RD53 and RD54 drives run hot (around 35W) and lots of cooling was one way to insure they lasted longer. Heat is the enemy of those older drives and it is not unusual to find a system there the fans were dead or clogged and the drives failed.. Allison > >Sridhar, > >A clean box sounda a good idea, could you provide some detaile please? > >Thanks, > >Andy. > > > > >On 09/04/07, Sridhar Ayengar <ploopster at gmail.com> wrote: >> >> Andy Piercy wrote: >> > So anyway sorry to ramble, After you opened the drive, did you have any >> > problems with dust and head crashes? Do you think that it would be >> possible >> > to fabricate one of these bumpers? Do you have any pictures of this >> bumper >> > within the drive? >> >> You could always make a cleanbox to do the work in. It isn't difficult. >> There are plans available online, but if you have trouble finding >> them, I'd be willing to describe how I did it. >> >> Peace... Sridhar >>

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by ajp166＠bellatlantic.net

> >Subject: MFMulation? (Solid-state replacements for MFM drives) > From: Entity <entity at nenevr.demon.co.uk> > Date: Sun, 15 Apr 2007 23:05:49 +0100 (BST) > To: cctalk at classiccmp.org > > >Hello, all. > >Does anyone on the list know if anyone in our extended community has ever >come up with some sort of plug-compatible flash memory replacement for MFM >drives? No. Flash has a write limit before failure. that makes it useless for swap/page space. Also the number of CHS combinations of old disks were numerous. >I've a vague idea that I've seen a commercial offering at some point in >the past, but obviously that'd be a fairly expensive move to make. >(Fairly? Oh, OK. Very.) > >I've got a Northstar Horizon that I mentioned on here many, many years >ago and I've just started looking at it again; once I've got it up and >running it'd be nice to add some sort of permanent storage, but without >jettisoning one of the floppy drives. The SuperIO board is one option, >but I'd like to keep it as stock-Northstar as I can. CF to s100 takes maybe 10 peices of generic ttl, It would require a new (or argumented) bios for CP/M and NSdos never supported a hard disk (or similar) without a rewrite (except on the Advantage). I've done both IDE and CF for 8085 and z80 systems as a way to get bulk storage for them. It's easy to do in hardware and a software project as there is no direct support off the shelf (one of hardware). Allison

19 years, 2 months

Atari ST/STacy was Re: MCM66128L20

by jvdg＠sparcpark.net

Ensor wrote: > > 1040ST lacked a floppy drive. 520STF and 1040STF had floppy drives > >(hence the 'F'). > > Here in the UK we got the "520STM" (no floppy, internal RF modulator) and > "1040STF" initially, and later the "520STFM"; I don't recall if there was a > "1040STFM". There was. I have one. You are right, as the 'F' indicates the internal floppy drive, the 'M' indicates the modulator. I was wrong, earlier, though; there was no floppy-less 1040ST. The 1M ST was called the 520ST+. This was probably done to make things interesting. ,xtG tsooJ

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by dm561＠torfree.net

Date: Sun, 15 Apr 2007 23:05:49 +0100 (BST) From: Entity <entity at nenevr.demon.co.uk> Subject: MFMulation? (Solid-state replacements for MFM drives) <snip> >I've got a Northstar Horizon that I mentioned on here many, many years >ago and I've just started looking at it again; once I've got it up and >running it'd be nice to add some sort of permanent storage, but without >jettisoning one of the floppy drives. The SuperIO board is one option, >but I'd like to keep it as stock-Northstar as I can. <snip> ------------- If you mean Howard Harte's SuperIO board, apparently he's no longer making or supporting it; too bad. mike

19 years, 2 months

Epson PC286UX

by brettdurham＠mybluelight.com

An embedded and charset-unspecified text was scrubbed... Name: not available URL: <http://www.classiccmp.org/pipermail/cctalk/attachments/20070416/36c07b34/at…>

19 years, 2 months

MFMulation? (Solid-state replacements for MFM drives)

by ajp166＠bellatlantic.net

> >Subject: Re: MFMulation? (Solid-state replacements for MFM drives) > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Sun, 15 Apr 2007 21:22:33 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 4/15/07, Roger Merchberger <zmerch-cctalk at 30below.com> wrote: >> Ah, but the beauty of this is, if you make it IDE compatible, you already >> *have* flash compatibility - just slap a CompactFlash module of your >> preferred size into a CF->IDE adapter, and Bob's your uncle! > >Since desktop drives are moving to SATA, compatibility with PATA (and >thus easily attached Compact Flash drives) isn't the obvious goal is >once was. Yes, there will be large amounts of PATA drives for a >number of years, but I can see that in a small number of years, they >just won't bother to make them anymore, whereas, Compact Flash is >Compact Flash - they may stop making that, too, but they aren't as >mechanically fragile, so they may be easier to track down 10+ years in >the future. > > >> I doubt there were MFM drives (read: ST506) available that hit the >> gigglebyte size > >There's an understatement - with a practical maximum number of >platters and heads and tracks and sectors with the techniques of the >times, no... they never got close to 1GB. They came out at 5MB >(ST506) and peaked under 200MB. ESDI was the interface of choice for >a short time if you wanted "large" drives on the desktop, then IDE >(PATA) swept in and here it is, sweeping back out like the tide. As >an aside, I happen to have a pair of 600MB ESDI drives on an SDI >controller on my VAX8200, so ESDI isn't just for large PCs, but they >were seen there. What made the jump possible was RLL. MFM drives could do RLL and those Xt2190 (153mb) drives now exceeded 200mb and climbing. IDE was simple pushing the RLL controller onto the literal back of the drive making the path clear for yet higher data rates to the platter. Cobalt replaced ferrite for the surface media, data rates went up. Better heads, amps and the like made even higher data rates possible so that 1Gb and higher was possible. By then GCR and other techniques were being applied to the problem of getting more into less. MFM was a starting point and had limited use because it didn't pack the maximum number of bits possible. Allison

19 years, 2 months

TC11/TU56 update

by wacarder＠earthlink.net

Warning: this is a long post. Today I racked my TU56 and TC11. I connected the TC11 to the TU56 with the two interface cables. I hooked up an AC power cord to the TU56. After turning on my H720 power supply and checking the voltages, I hooked up the +5, -15, and ground wires from the H720 power supply to the spade connectors on the TU56 and the TC11. I then opened up my 11/40, removed my M9312 bootstrap terminator from the last unibus slot (on my RK11-D), moved the M9312 to the unibus-out slot on the TC11, and ran a unibus cable from the slot on the RK11D (where the M9312 previously was located) to the unibus in slot on the TC11. I then powered everything up (11/40, RL02, RK05, TU56, VT100). This configuration has two RL02 drives, an RK05, and the newly added TU56. I have the appropriate bootstrap ROMs in the M9312. IIRC, the RK05 ROM also contains the dectape bootstrap code. I put a "never-used" DecTape on both drives, wrapped it around the take up reel 4 or 5 times, set the TU56 in local mode and pressed the forward switch to wind the tape a little more. I then loaded the address of the M9312 and pressed the start button. The @ prompt appeared on the console. This showed that the unibus signals and the M9312 are working in the TC11. I then decided to boot RT11 from the RK05 drive. It booted fine. The system seemed to be working normally and adding the TU56/TC11 did not adversely affect anything. Then I decided to test out the DecTape drive to see if it would respond to RT11 commands. Although there was nothing on the Dectapes, I did a DIR DT0:. The drive 0 reel began spinning and spun back to the beginning and the tape came off the take up reel and kept spinning. I flipped the unit 0 toggle switch from the REMOTE position to the OFF position, then wrapped the dectape back on the reel a few turns, set the switch to LOCAL, and wound it using unit 0's forward/reverse switch. I did the same thing with unit 1 (DIR DT1:). Exact same results. The tape winds and goes off the reel. If I attempt to do an INIT DK0: or INIT DK1:, the tapes run in forward motion until they are totally wound on the take up reels and then keep spinning. When it runs off the reel and I turn the DT0 or DT1 unit's REMOTE/LOCAL switch to the OFF position, RT11 returns an error message to the VT100 console. If I attempt to boot off a Dectape (entering DT, DT0, or DT1 at the M9312 @ prompt), the drives spin in forward direction until they wind the tape all the way onto the take up reel and then keep spinning. The indicator lights on the right side of the TC11 panel seem to be working fine, and when the tapes wind off the reel and I flip the REMOTE/LOCAL switch to OFF, the error light with come on. So it seems that the TC11 and TU56 are communicating with the 11/40 system, and the system can send commands to either dectape unit 0 or unit 1, and the TU56/TC11 will respond. My question now is: If I want to initialize a blank, never-used Dectape so I can use it under RT11, am I doing the right thing by typing INIT DT0: or INIT DT1: ? How is the dectape unit supposed to respond when I issue an INIT DT0: command? I would assume that it should not wind the tape until it winds it all the way off the reel. Where do I go from here? It seems that I'm mighty close to LIFT-OFF!!! I'll post some pics of the racked TU56/TC11 on my web site soon. Ashley http://www.woffordwitch.com

19 years, 2 months

govliq: LG01 DEC printer (San Antonio, TX)

by legalize＠xmission.com

LOT (5)ELECTRONIC EQUIPMENT INCLUDES HP 3330B SYNTHESIZER, HP 214A PULSE GENERATOR, DEC LG01 PRINTER, RONAN X76ETM4X GAS ALARM CONTROLLER, TRANSFORMERS, STANCEL RECORDER/ REPRODUCER <http://cgi.govliquidation.com/auction/view?id=1181500&convertTo=USD> -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

19 years, 2 months

TU-58s (was Re: Some progress with my PDP-11/73 system)

by ajp166＠bellatlantic.net

> >Subject: Re: TU-58s (was Re: Some progress with my PDP-11/73 system) > From: "Jerome H. Fine" <jhfinedp3k at compsys.to> > Date: Thu, 05 Apr 2007 16:35:21 -0400 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > > >Allison wrote: > >>So happens one of my "small" pdp-11s uses a Tu58. the system is a BA-11V >>with an 11/23 256k of ram, DLV11J and MRV11 rom(boot). Takes 10 minutes >>to boot, setup VM: then copy key files to and reboot. After that it's >>pretty decent even if I have to access a file on tape. >> >>Everytime I runs it with a bunch of kids of the current PC generations >>they go gaga and comment on how slow then I explain the amount of ram and >>storage then they are amazed it can be a functional machine with so little. >>They can't imagine a useful machine with 32kW of ram and 256kb of storage. >> >> >Jerome Fine replies: > >At some time or other, I saw a VT103 with dual TU-58 >drives in the bottom. As noted, it took about the >lunch break to boot. Files in wrong order. I learned how to make a pdt11/130 boot faster and thats a LSI-11 no extra ram. One trick was to put bad blocks at the end of each track to fource files to be sequential without wraping around to the beginning. Saved a lot of long rewind/seek operations. >However, a VT103 can actually support a PDP-11/73 >with all 4 MBytes of memory if the backplane is >upgraded to 22 bits. The other 2 quad slots can >have items like a TQK70, a DHQ11 and an RQD11-EC >which allows up to 4 * EDSI hard drives. In the >case of ESDI hard drives, I STRONGLY suggest >used a separate power supply. Otherwise, an >RQDX3 with an RD51 can also be used and it is >then possible to place the RD51 under the tube. A RX180 (VT180) disk box with a floppy and a st225 and a VT103, a sweet system with a 11/23 or faster CPU and 4mb ram (run VM:!) >At that point, you can play games with those PC >generation of kids and tell that that you don't >even need a computer, just a monitor and keyboard! > >If you use a dual PDP-11/73 or PDP-11/23 with a >DLV11-J (and no boot ROMs on the CPU), then >the SIGMA controllers are very handy, either >a dual MFM (or ESDI) version or the quad ESDI >version. Again, with the dual MFM version, >an RD51 (ST412) can be placed under the tube >and use the internal power supply of the VT103. > >It must be about 20 years ago that I did this >conversion of the RD51 hard drive under the >tube. I think I still have the backup VT103, >but without any boards or a suitable controller. > >With any ESDI drives, limit the use of the internal >power supply of the VT103 to a single drive for less >than 10 seconds which would probably be enough to >boot and copy any needed files to the VM: device. Sounds nice. I have a few BA-11VA (four dual width slots) and it's a challange to put enough boards to make a bootable viable sytem in that. An 11/23, 256k ram, DLV11J and a Rom card was full house and for storage the only choice was TU58 or Tu58 emulation (requires bukly balky PC). Though at one time Sparetime Gizmos offered a TU58 emulator in hardware using ram with battery backup (total of 512k or DD0/DD1). I have one of them and that is remarkably fast as there are no seek dealys and at 31k baud you can move enough to appear decently fast. There was also a third party TU58 like system that also used serial and instead of a tape it was rx50 compatable floppy. I'd love to find one or at least drawings and rom code. Allison >Sincerely yours, > >Jerome Fine >-- >If you attempted to send a reply and the original e-mail >address has been discontinued due a high volume of junk >e-mail, then the semi-permanent e-mail address can be >obtained by replacing the four characters preceding the >'at' with the four digits of the current year.

19 years, 2 months

MCM66128L20

by melamy＠earthlink.net

the IBM AT used two 64K piggybacked chips for a total of 128K. I don't have the chips is front of me right now, so I can not tell you if they were MOT chips or not. As for possibilities, all one has to do is approach a chip mfg and ask them to create the bond out of the chips so they can be piggybacked. Not all that hard when you have money to throw at a company. I am sure that is what IBM did. All that would need to be done is swap an unused pin with a chip select pin. One line goes to the top chip and the other goes to the bottom chip. Power, RAS, CAS, address and data can all be connected together. best regards, Steve Thatcher By the way, I did not read any of the other posts on this topic, so please forgive my intrusion if not helpful. -----Original Message----- >From: Alexandre Souza <alexandre-listas at e-secure.com.br> >Sent: Apr 11, 2007 7:19 AM >To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> >Subject: Re: MCM66128L20 > >>>That's the first thing that puzzles me. It was my understanding that >>>these were 128Kbit chips, so 18 of them would give you 256K bytes (+ >>>parity) of memory. Can you confirm, please, that 18 of them really are >>>512K >>>> The top chips are stamped MCM66128L20; the bottom chips have no part >>>> number. > > Maybe the bottom chips are just EMI filters/pull ups??? :oO > > There are NO possibilities that memory can be piggybacked this way. When >you piggyback two memory chips, at least ONE of the pins must be routed >separately. At least this is what logic tells me. > > I never seen a 128K *D*ram chip. SRAM exists. This is something that is >driving me crazy here, I cannot find any datasheets/pinouts on this part >number, nor any kind of info. Crazy. > > IF the memory was 16-bit-word, maybe you could be using 256K chips > > What was the replacement part you got? > > Greetings, > Alexandre >

19 years, 2 months

Atari ST/STacy was Re: MCM66128L20

by classiccmp＠memory-alpha.org.uk

Hi, > Will a CGA monitor be able to handle 320x200 lo-res? I wonder if >people have tried hooking them up to Commodore 1902s or 1084s. I used to use my 520STM+ (a 520STM factory upgraded to 1MB RAM, a UK only thing I believe) on a Philips CM8833 monitor, it would handle both low and medium res without a problem. I know STs can also drive CBM 1701s without a problem. However, unless the monitor output of the STacy is different to the normal ST, it won't drive a CGA monitor. CGA monitors expect TTL RGBI, whereas the ST outputs analogue RGB (albeit at TTL levels, hence the reason for having to install dropper resistors in the RGB lines when driving a normal, non-Atari colour monitor). TTFN - Pete.

19 years, 2 months

Atari ST/STacy was Re: MCM66128L20

by classiccmp＠memory-alpha.org.uk

Hi, > I know of a 260ST, not a 540. There was also talk of a 130ST. Ah, that explains a few things - I really should go take a look at a few Atari sites, it's been a while. TTFN - Pete.

19 years, 2 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