test-drb

test-drb@ccmp.vtda.org

101090 discussions

by bobstek＠ix.netcom.com

>> Andrew Davie[SMTP:adavie@mad.scientist.com] writes: >> >> >S-100 George Morrow Disk Jockey 2D/B >> >> Hmm, 50 pins, could that possibly be a SASI card? >> As in Shugart Associates pre-SCSI bus >> > >No. It's sa1000 series 8" hard disk interface. > >Allison I've got 50 cents that says the DJ 2D/B is a floppy controller, not a hard drive controller! Bob Stek bobstek(a)ix.netcom.com Saver of Lost SOLs

27 years, 7 months

OT - Declaser 1152

by jim＠calico.litterbox.com

Okay, it's not quite a classic since it's only 7 years old, but does anyone know whether the simms inside a declaser 1152 are standard 30 pin mac simms or if they're something wierd? I desperately need to upgrade my old declaser - it keeps running out of ram printing things and Kinkos wants $.49 US per page to print things to their very fast and powerful IBM printer. Alternately does anyone out there happen to have the 2 meg expansion (part number LN07X-UF) for the thing? -- Jim Strickland jim(a)DIESPAMMERSCUMcalico.litterbox.com ----------------------------------------------------------------------- Vote Meadocrat! Bill and Opus in 2000 - Who ELSE is there? -----------------------------------------------------------------------

27 years, 7 months

Need some O.T. help

by gregorym＠cadvision.com

At 02:54 PM 2/4/99 -0800, you wrote: >On Thu, 4 Feb 1999, Tony Duell wrote: > >> Automatic power switches are nothing new. The odd-numbered PERQs (1, 1a, >> 3a) all had software-controlled turn-off. So does the Whitechapel MG1 and >> the Torch XXX. > >And the Apple Lisa. And it too has problems sometimes not allowing you to >power down (you must either unplugged the system or trip one of the two >microswitches that sense whether you opened the front bezel or back access >panel). And the NeXT Cubes. I've never had a problem with the machine hanging when you want to power down. I have however had some involuntary shut downs when the !@#$%^& laser printer comes on to warm up, and blows the breaker on that circuit. :v) Mark > >Sellam Alternate e-mail: dastar(a)siconic.com >--------------------------------------------------------------------------- --- >Always hasslin' the man. > > Coming in 1999: Vintage Computer Festival 3.0 > See http://www.vintage.org/vcf for details! > [Last web site update: 01/15/99] > > >

27 years, 7 months

HP TSB, Docs and O/S

by jlwest＠tseinc.com

So - you're sure you don't want to just give that machine up? <grin>... Just out of curiosity, what modem of disk drive is it? I'll have some docs somewhere for that stuff soon enough. I know I already have all the docs on the tape reader... Jay West -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Thursday, February 04, 1999 4:50 PM Subject: Re: HP TSB, Docs and O/S >> >> I'm glad I got the first batch of docs for the 2100 stuff. But given that >> the second batch of HP docs which I did not get went so fast, I have to >> suspect there's some other 2100/21MX lurkers on the list :) One of these > >I have a 2100 CPU + paper tape reader + disk drive. The latter takes >RK05-like packs, and is in very poor condition. The whole lot was rescued >just before it became scrap metal... > >Alas I have no docs, and I think I'm going to need a schematic of the >board in the CPU box before I can do much. I have all the CPU boards (but >not the WCS option), 4 sets of core memory (missing one top connector) >and a lot of I/O boards. > >It is very much a 'to be done one day' project. Yes I am glad I rescued >it, but until I get some more info it's going to be sitting in my machine >room... > >-tony > >

27 years, 7 months

Need help on old Tandy stuff -- Allison? Anyone else?

by sinasohn＠ricochet.net

At 10:51 PM 2/1/99 -0600, you wrote: >> Computer (Sharp) or the Model 100 (Kyocera). I'm not sure about the M200, >> but I suspect it might have been made by Kyocera as well. Uncle Roger >> knows more about all of the different Kyocera clones. >I didn't know about the Kyocera connection, however. Interesting.... Tandy may have *made* the m100; Kyocera *designed* it. I think Tandy redesigned it (tweaked it) into the 102; they probably did the design (based on the original Kyocera design) of the 200. FYI, there are 9 versions of Kyocera's design: Kyocera KC-85 TRS-80 Model 100 TRS-80 Model 102 (mostly the same as the 100, only lighter and cheaper) TRS-80 Model 200 (clamshell, with larger screen) NEC PC-8201 (Japanese version, with Katakana? charset in ROM) NEC PC-8201A (American version) NEC PC-8300 Olivetti M10 (American version) Olivetti M10 (Euro version) Not related, but possibly mistaken as such: TRS-80 Model 600 NEC PC-8401A "Starlet" NEC PC-8500 Olivetti M15 I don't know if Kyocera ever came out with anything after the KC85. --------------------------------------------------------------------- O- Uncle Roger "There is pleasure pure in being mad roger(a)sinasohn.com that none but madmen know." Roger Louis Sinasohn & Associates San Francisco, California http://www.sinasohn.com/

27 years, 7 months

MORE!!! FS/FT: HP Documentation

by rigdonj＠intellistar.net

OK I'll join in. Here's my offering: HP 1000 Computers, Hardware Data. 8 1/2 x 11" size, date 5/79. This list ALL the hardware specifications and options for the 2100 M, E, and F series machines. Also all the specs for the memory systems, mainframe plug-ins, Firmware products, microprogramming accessories, Power fail recovery systems, input/output and memory extenders, I/O interfaces, environmental specifications and prodduct support information and finally the complete power specifications and applicability summary. Only VERY interesting trades considered! JOe

27 years, 7 months

Are there any Telex fans out there?

by rigdonj＠intellistar.net

I got a bunch of old disks yesterday. So far I've found some in the CPM 86 format for the PC, Telex CPM format, CPM for the Osbourne 1, 8" soft sectored disks for unknown system and one hard sectored 8" floppy. It looks like many of them came from Telex's office in North Carolina. Many of them look like reports of test on different models of equipment, equipment specifications, etc. A couple look like they have ROM code and different revisions of system software. I need some one that's familar with Telex's products that can tell me what some of these things are. Joe

27 years, 7 months

TelePickup in Chicago

by dogas＠leading.net

Hi, If anyone is in the Chicago area and wouldn't mind a (several heavy items: multiple TRS-80 16b and 6000HD systems) pickup and subsequent packing/shipping job expenses paid with maybe a system or two ( ;) ) thrown in for effort Please send email Thanks - Mike: dogas(a)leading.net

27 years, 7 months

tube CD player (was Re: sizes (was Re: vacuum tube computer))

by Philip.Belben＠pgen.com

Eric has replied to my post with a lot of good points, but I don't understand this one: > After you do the D/A, you have a huge amount of sampling noise at Fs/2 (and > its harmonics). For a CD player, Fs is 44.1 KHz, so the sampling noise is at > 22.05 KHz. Since the desired audio frequency response extends to 20 KHz, a > non-oversampled player needs "brick wall" analog filters, with a pass band to > 20 KHz, and a stop band starting below 22.05 KHz. > > Digital oversampling is used to move the sampling noise to a higher > frequency. 4x oversampling moves it to 88.2 KHz. The oversampling filter > is a low-pass filter, so the audio content still has a frequency response > to somewhere above 20 KHz. But now your analog filter can have a much > shallower slope, which is easier to implement and introduces much less > phase distortion. > > Your analog oversampling scheme does not eliminate the noise at Fs/2, > and in fact introduces more sampling noise at higher frequencies. It does > not help reduce the requirements of the analog filter. Don't confuse sampling noise with quantisation noise. Quantisation noise is due to the replacement of an analogue value by a digital representation not exactly the same; it is reduced simply by having more bits of precision (there are other tricks, including things involving oversampling, but they only cloud the issue). Sampling noise is present in a sampled waveform whether it is a sequence of digital numbers or of analogue values. It arises from the deviation between the original waveform and the sampler output (with no filtration at all this is a series of steps) at the intermediate points between samples. Oversampling interpolates intermediate samples, and uses a filter to reduce the sampling noise due to not having known what those intermediate values should have been. While I admit that the linear interpolation I described is a rotten oversampling filter - it was only mentioned by way of an example - the mathematics are the same whether you use a digital computer to generate the digital numbers at your oversampled points or a switched analogue circuit such as I described to generate analogue values at the intermediate points. This analogue circuit can also (theoretically) reduce quantisation noise even compared with digital oversampling, since the intermediate values are not limited to the precision of the DAC. In practice, quantisation noise probably is probably slightly higher, since the intermediate values are limited to the precision of the resistor networks that derive them. So why does this sort of analogue filter not reduce the sampling noise at Fs/2? If it introduces noise at higher frequencies (which I agree it does), this is because the noise arises from conversion of samples to a continuous function, not from conversion of digital to analogue. > The logical extreme of oversampling is to use such a high factor that you only > need one bit of data. This is called a delta-sigma D/A converter. For 16-bit > source data this would require at least 65536x oversampling, but there are > some tricks to reduce this to e.g. 128x. This is the basis of the so-called > "1-bit" D/A converters. The advantage is that you only need a single-pole > analog filter (and in practice can get by without even that), and that the > tradeoff from quantization to time domain has been maximized, which is good > because it is much easier to get high precision in the time domain as > described above. I have met delta-sigma encoding, but I never managed to work out how you get the sampling rate down to a manageable value. Since we're getting a bit off topic here, could you post not an explanation but a reference to somewhere I can look up this particular aspect of the problem. Philip.

27 years, 7 months

3-phase (was: Re: CDC 9766 Drive and packs)

by amirault＠epix.net

Hi, OK. What you are saying is that you have a functionally obsolescent electric service that needs to be upgraded to a 200 amp service to better handle todays electric needs. I suggest that you contact your electric company and find out how much this upgrade will cost you. John Amirault -----Original Message----- From: Eric Smith <eric(a)brouhaha.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Thursday, February 04, 1999 3:34 AM Subject: Re: 3-phase (was: Re: CDC 9766 Drive and packs) >> Why not just go out and BUY a three phase converter? You know that such a >> thing does exist now. > >As the person that started this thread, I can certainly explain why *I* >don't buy one. > >The equipment I want to run will need about 45A per phase. If I had >an 85% efficient converter, I'd need an 80A 240V circuit. The entire service >entrance to my house is only 100A, and I use more than 20A of that for >lighting alone, not to mention the microwave oven, audio and video gear, >and modern computers. > >Normal US homes are not wired for big old computers and their peripherals. > >

27 years, 7 months

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