test-drb January 2007

test-drb@ccmp.vtda.org

238 participants
538 discussions

by legalize＠xmission.com

<http://www.dovebid.com/assets/display.asp?ItemID=tbd310965> -- "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/>

17 years, 6 months

Lisa (was Re: Olivetti M20)

by roger.holmes＠microspot.co.uk

> Date: Wed, 17 Jan 2007 13:31:05 -0500 > From: Ray Arachelian <ray at arachelian.com> > Subject: Lisa (was Re: Olivetti M20) > To: General Discussion: On-Topic and Off-Topic Posts > <cctalk at classiccmp.org> > Message-ID: <45AE6B69.7020506 at arachelian.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Roger Holmes wrote: >>> >> Well OK 5k dollars is not much, but in January the following year for >> 10k, Apple's Lisa had several of the above, though I have to admit I >> have seen some spectacular crashes as it was possible to corrupt the >> sound buffers and also to seriously derange the CRT scanning. > Erm, I'm not sure how this is possible as the Lisa had no sound > buffers > at all. All it had was a bunch of resistors hooked up to a latch in > order to act as a volume control for the VIA's shift register. It > beeped in the same way as the Commodore PET. That is by setting > timer2 > on the VIA and setting a value in the SR, then setting the ACR to loop > the data in the SR. There was no sound buffer, there was no way to > play > anything other than beeps. Oh, I must be getting confused then. After developing for Lisa we continued to use the Lisas as hosts to develop software for the Mac using a serial cable to send the software and to run the debugger on the Lisa screen and the target software on the Mac. I think at first we had Lisas with twiggy drives so we could not write Mac discs on the Lisa, but maybe I've got it wrong again. I do know that Apple loaned us a Mac with a 5 1/4 inch slot in it for a twiggy drive, though there was a 3 1/2 inch installed in it. That would probably be worth something now. Back to the crashes, I remember they really made you jump out of your chair, the screen went haywire and the horrible sound it made like hitting bone with a coarse circular saw. Though the Lisa was black and white, the phosphor must have been made of a mixture of two, as you could get a purple effect if you crash made the screen flash at a particular frequency, and on another time it seemed to make one flash of pale green, though maybe thats the 'Pink Elephant' effect. Even with only square wave output you can make more than beeps, my old mainframe built in 1962 can play crude music. Not that Handel and Bach wrote crude music, it was the rendition which was crude. > > Nothing is available to the OS to derange the CRT scanning. All > you can > do is enable interrupts on the vertical retrace, or disable said > interrupts, and you can also select which 32K of memory to use as the > framebuffer. That's it. Yes thats all the system routines allow anyway, I just checked (on Lisa). As both 128k Macs and Lisa had a single built in CRT I can't see why the refresh rates would have been programmable, but thats just how it appeared. The only other option I can think of is we had somehow managed to do something which had affected the power supply rails, but the machines rebooted OK so there was no permanent damage. Could switching the position of the framebuffer between frames full of ones and ones full of zeroes cause this perhaps? I remember you could get the spark gap capacitors to fire on old monitors on the Apple ][ when you rapidly changed the screen image. The screen image would expand and contract while this happened. > > >> The compiler generated some strange code to 'touch' the new top of >> stack on subroutine entry so the OS could allocate all the extra >> space >> in one go rather than in little bits. One enterprising British >> software house even got Unix running on a Lisa with the (then) >> optional 5MB profile hard disk. It wasn't C.A.P. but one of the other >> big ones of the time. > There were two. Microsoft/SCO Xenix, and UniPlus. I'd love to get my > hands on UniPlus, but it seems to be rare. If this was something > else, > it would be wonderful to get a copy of it. Maybe the UK firm was merely selling one of these under licence. > > I'm not sure what the strange code is about, I suspect something to do > with the MMU. If you'd access a page that wasn't mapped to your > process, the OS would either load it from disk, or allocate more MMU > pages to your process, thus getting more memory. The Lisa Pascal compiler had an option for "automatic stack expansion". IIRC, this was off when compiling for Mac and on when compiling for Lisa. Each routine started with something like LINK A6,#constant where the constant was the space for the local variables and maybe the parameters too. If automatic stack expansion was on, the compiler would then generate the weird instruction, which was not useful to the program but would apparently cause the allocation of more stack space if necessary. I have just found the reference in the manual: "6.6.1 The Run-Time Stack Automatic stack expansion code makes procedure entries a little complicated. To ensure that the stack segment is large enough before the procedure is entered, the Compiler emits code to 'touch' the lowest point that will be needed by the pocedure. If we 'touch' an illegal location (outside the current stack bounds), the memory management hardware signal a bus error that causes the 68000 to generate a hardware exception and pass control to an exception handler. ... then allocate enough extra memory to the stack that the original instruction can be reexectuted without problem. To be able to back up, the instruction that causeed the exception must not change the registers, so a TST.W instruction with indirect addressing is used." It then goes on to talk about a compiler fudge factor and what gets generated if more than 32k of extra space is needed on the stack, and what is needed if working in assembly language. Best regards, Roger Holmes.

17 years, 6 months

cctalk Digest, Vol 41, Issue 52

by dm561＠torfree.net

>Date: Thu, 18 Jan 2007 12:58:14 -0500 >From: "Evan Koblentz" <evan at snarc.net> >Subject: RE: Ebay idiocy <snip> >The man just wants some reassurance that his time and hard work >will be appreciated. What's wrong with that? More people in >our hobby should be that devoted! >- Evan -------------------- A rather naive perspective, I think. Aside from whatever personal interest he may have in classic computers, he's also in it for the money and apparently wants to generate enough traffic for VCM to generate revenue and potentially sell it for some ridiculous (IPO) amount. As Warren points out, competing with eBay is a rather dubious business proposition anyway, but ranting at and offending his potential customer base with foul language for doing business with his "competition" does not strike me as a very effective way of creating the good will that a successful business venture needs; he should spend his time advertising and promoting VCM instead. mike (cc to Sellam)

17 years, 6 months

Jules Richardson wrote on "Digital Archaeology of the Microcomputer, 1974-1994

by aek＠bitsavers.org

>> So the question is what should be saved? Is there something about the >> 'exotic hardware/software' that is historically significant? > Well, if you adopt the "only historically significant" things are to > be collected mantra, you never would have had something like the Henry > Ford Museum in Michigan. *All* of the stuff he amassed for that > collection was considered not historically significant at the time. > Now its amazing to be able to walk down an aisle and see the evolution > of the sewing machine, or the dishwasher or the clothes washer/dryer, > etc. > > I think there are some things you can say have obvious historical > value. Others aren't historically significant *by themselves* but > allow you to make a realistic historical portait because they > represent samples of devices over time. This is an argument that people in archives and museums have to confront every day when donations come in. If there was infinite conditioned storage space time/money to process donations, much more would be accepted than happens in the real world. As a curator, I have to make the decision to commit CHM's resources to preserve something in perpetuity. From the time I have spent talking to Doron Swane about the British Science Museum's collecting policies this is not unique. "You cannot save everything, where would you put it?" isn't a joke when you are talking about collections expected to last hundreds of years. One of the most serious responsibilies that I have, along with the activities of physical and electronic artifact preservation at CHM is making the decision to accept an artifact into the collection. Things created in the PC era and forward are especially difficult, since there was so much produced in a fairly narrow product niche (personal computers). Do you need to save EVERY version of a software package (and all of the documentation)? Remember, storage and processing isn't free.

17 years, 6 months

Old Digital Disk Drives

by thomas.gardner＠sbcglobal.net

Hello: I'm working with the Computer History Museum, Mountain View CA, on a project to identify significant disk drives - the RP01 and RP02 have been so identified. Would anyone on this mail list have any knowledge of any such drives still in existence, operational or not? Tom Gardner Los Altos CA

17 years, 6 months

Latest eBay BS (OT?)

by marvin＠rain.org

> From: Jim Leonard > > William Donzelli wrote: > >> their policies back. Nobody will notice if everybody from this list quit > >> ebay forever. > > Gee, I guess we ought to just give up then. > Yes. > > Why bother voting, too. > That's a terrible comparison. There are less than 1000 people on this > list, "voting" against a company of 90,000+ employees in a Fortune 100 > company. There are more efficient and useful ways to spend your time. Voting is a terrific comparison. For some reason, you think that the only uproar is taking place on this listserver ... you are wrong there. Perhaps you (and others on this list) are not aware that among other things, people have reported that they can find out what the bidders proxy bid is using apparently legitimate software. Shill bidding *is* a concern and Ebay is doing their very best to prevent users from detecting shills. I see nothing to indicate that Ebay is doing anything other than attempting damage control.

17 years, 6 months

Olivetti M20

by roger.holmes＠microspot.co.uk

> >> 1) To prevent one process overwriting the memory belonging to another >> process. >> Segments did not HAVE to be 64k, that was their maximum size, the >> minimum >> was 128 bytes. >> 2) To provide virtual memory. >> 3) To protect the executive from processes. >> 4) To allow non contiguous physical address space to appear as a >> logical contiguous address space >> 5) To provide mapping out of faulty blocks of memory >> and probably as many reasons I have not thought of off the top of my >> head. > > Consider the time this was introduced. It was a $5K personal > computer from 1982 whose base configuration was 2 floppies and no > hard disk. Just about any of the above was probably held to be > superfluous by most manufacturers in that context. Well OK 5k dollars is not much, but in January the following year for 10k, Apple's Lisa had several of the above, though I have to admit I have seen some spectacular crashes as it was possible to corrupt the sound buffers and also to seriously derange the CRT scanning. The compiler generated some strange code to 'touch' the new top of stack on subroutine entry so the OS could allocate all the extra space in one go rather than in little bits. One enterprising British software house even got Unix running on a Lisa with the (then) optional 5MB profile hard disk. It wasn't C.A.P. but one of the other big ones of the time. Before I left Marconi in 1980, we had at least one Z8010, but I don't know what date they became commercially available. Fitting one might well have saved Olivetti money, depending on unit price of course.

17 years, 6 months

HP2645As.... again

by legalize＠xmission.com

Ebay item # 280070687500 The seller has zero feedback, indicating to me that he stumbled across these terminals and liquidating them gave him the impetus to create an ebay account. Jay, shall we try again at a bulk purchase? He's got 30 of them, and its not clear if they are all 2645As and some of them might be 2648As. The seller says some are used, some are new, although I don't know how you could tell from his picture of the pile :-). Maybe the "new" ones are the ones with the little cover for the switches on the upper left of the keyboard? -- "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/>

17 years, 6 months

Another super-useful find: single Sun 200-pin 128MB DSIMM

by compoobah＠valleyimplants.com

If you have an Ultra-class 200-pin machine with one broken 128MB DSIMM and you're wondering what to do with the other: 1 free 128MB DSIMM (no, it doesn't work in SPARCstation 20s) Renton, WA

17 years, 6 months

General Automation Zebra!

by jwest＠classiccmp.org

In a prior life I owned a company that was a Pick dealer (Pick Systems, Microdata, GA, Ultimate, etc.), so all kinds of interesting Pick-related stuff still floats around the house and I rediscover things from time to time. Today one has surfaced that I thought was lost forever. My father sold his business recently and in cleaning out things he found a QIC cartridge tape I had left there for safekeeping as an off-site backup many years ago. It's a GA (General Automation) Zebra Pick OS Dealer Sysgen tape. This is a tape that was only provided to GA dealers (for dealers to replace an end-users lost or damaged boot tapes, or to sell with new systems {the licensing was in the terminal ports, not the OS}). It was an Account-Save format tape of an account called DEALER-SYSGEN. On that account was stored the monitor and ABS sections for every different system GA made. A menu ran when you logged on to the account and it asked you what system you wanted to make an OS load tape for (1700, 1750, 2820, 3820, 3000, 3500, 5500, 7820, 8830, etc.), and what tape media you want the tape created on (QIC or 1/2 mag tape). It then wrote a complete bootable tape with bootstrap, monitor, abs, and files sections for any of those systems. What a find!!! Of course, I haven't tried to read this tape, perhaps it's got some worthless datafile backup from something else on it. But it still has the original GA Zebra lable stating it's the dealer sysgen tape and the write protect is on.... so I'm hopeful. I happen to have a GA1750 and a GA2820 in my collection, so I'm thrilled to know that I can make new boot tapes for them now. More importantly, I can make boot tapes for any other GA Zebra system. Note that this tape is for rev 3.8, which was the last non-R91 Pick GA produced (I wasn't a fan of R91, so I'm really glad it's the pinnacle of the 3.8 train). I need to see if I can find my manual patch sheets that bring it up to 3.8T1. Anyways, if anyone has GA Zebra's in their collection and needs a new boot tape I can help you out. Now I just need to find the DEALER.ASSY account for 3.8 :) Jay West

17 years, 6 months

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test-drb January 2007