test-drb May 2009

test-drb@ccmp.vtda.org

204 participants
322 discussions

Mac pointers and handles. Was: Chips that changed the world

by roger.holmes＠microspot.co.uk

> From: Ethan Dicks <ethan.dicks at gmail.com> > Subject: Re: Chips that changed the world >> Then of course there were those programmers that thought they were >> clever, using the top 8 bits to store flags in pointers, etc. ? >> Royally >> messed up when upgrading to 68020 and up. > > I remember reading a warning against such practices the original Mac > system manuals (the "hernia manuals"), but faced with 128K of RAM, > early programmers did not universally heed the warning. As I remember it, the warning was there because Apple had already used the top eight bits of pointers to hold flags for locked, resource, purge-able etc and if you wrote over them the OS crashed or made your application crash when it overwrote your flags. A big chunk of one the developer conference was going 32 bit clean, whereby developers had to use system routines to test and set the flags instead of system macros which had been compiled into our source code without us realising they were macros. For instance it was normal to get the status byte of a handle before locking it and instead of unlocking it, restore the status byte. As these had been done using macros they just went straight to the master pointer and acted on its top 8 bits. There were also system calls or macros for extracting the lower 24 bits which very few people had used as it worked without, but Apple wanted us to use them so they could redefine them to do nothing later. Saving a few bytes caused both Apple and its developers a huge amount of effort later on. Incidentally, you refer to the "hernia manuals". Do you mean the ring bounds ones? At least you could split them up, volume 5 was the problem one, it was a paperback about 2" x 8.5" x 11". Later there was a volume about OCE (IIRC, Open Connectivity Environment) which was as bad if not worse, but at least I never needed to read it, I think that technology died because the application programmers were intimidated by the size of the manual. Does anyone here happen to have a copy of the original loose leaf QuickDraw 3D manuals? Someone chucked out my copy at work thinking they had been supeceeded, but they were far better than the later documentation and still apply to the Quesa open source project I use in my work. I would be willing to pay for them to be copied or scanned, maybe they could go on BitSavers or be put in the official Quesa documentation at SourceForge. Roger Holmes.

17 years

More P112 boards coming

by dgriffi＠cs.csubak.edu

Enough people are asking about the P112 that I think I can justify taking preorders. I don't know exactly how much it'll cost for this run, but I'm fairly sure it'll be decently similar to how it was last time, which was US$165. I'll have the parts costs calculated out in a couple days. Then I'll know how many preorders will be needed to get things rolling. Stand by for more info. I anticipate three visible changes in the kit. 1) Depending on how many 32k chips I have left, I may go ahead and make 1M modules of the sort that Terry made up a while ago. 512k chips in DIP packages is very expensive, but for SMT packages, it's very cheap. The 1M module is nothing more than a daughterboard that plugs into the P112 and behaves exactly like a pair of DIPs. 2) Add two holes near the RTC crystal. I think it would be cleaner to use a loop of wire to hold the crystal down instead of a blob of epoxy. 3) Change the battery holder to something more compatible with add-on boards. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years

machine room in a trailer?

by legalize＠xmission.com

Has anyone ever setup an appropriately controlled environment for a machine room in a mobile home type trailer? -- "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

Apple II swift board

by shoppa＠trailing-edge.com

> I've never heard of the "Swift board for the Apple II". Googling > didn't turn up anything useful, although maybe I just didn't use the > right incantation. Try "SwyftCard". It's interesting to see how the concepts that were swimming around in Jef Raskin's head turned up and around into realizations in the 80's. Tim.

17 years

Looking for IBM PS/2 or PCjr Speech Adapter Tech Ref

by mbbrutman-cctalk＠brutman.com

The PCjr Speech Adapter sidecar is rumored to be identical to the PS/2 version, at least as far as the BIOS support on the adapter goes. I'd like to play around with mine, but the only programming notes I can find are in BASIC using some assembler hidden in some DATA statements. If I get really desperate I can extract the relevant code from the DATA statements, but I'm hoping somebody has the tech ref. Thanks, Mike

17 years

Bitsavers size in historical storage units

by quapla＠xs4all.nl

> I just noticed that the total size of the Bitsavers archive seems > to have surpassed 100 Gigabytes in the past few days. > > In historical storage units, that is 160000 miles, nearly one light > second, of paper tape. Hmm, how big/high would the pile of chad be? > > That is 1.25 Billion punched cards. At about 143 cards to the inch, > those punced cards would make a stack 137 miles high. Production of that > many cards would require three major deciduous forests, which by my > exchange > table is also the same as one ship's peanut. > > That is 40000 RK05 carts. At about 10 pounds per cart, that's almost half > a million pounds of RK05's. > > Great job, Al! > > Tim. > -- Certified : VCP 3.x, SCSI 3.x SCSA S10, SCNA S10

17 years

head transformer for Sony disk drive

by ard＠p850ug1.demon.co.uk

This is a very long shot (but it's on topic), so here goes. I have some of those Sony full-height single-sided (single head) 600rpm 3.5" floppy drives -- the ones that are used in the HP9121, HP9133V, early Apricot PCs, etc. Now, on the main board of these drives is a little ferrite-cored transformer. This is the only drive I've ever worked on that doesn't have a centre-tapped read-write head, and this transformer frovides a balanced signal into the read amplifier chain. It's surrounded by transistors that are involved in the read/write switching (this is not done with diodes as is conventional). Unfortunately, I've mechanically damaged (read 'ripped it off the PCB') this trnasformer in one drive of one of my HP9121s (long story...). So I need to do somehtign about it. I can't find a 'spare' single-head drive in my junk box, and I can't get a double-head one to work in the 9121 (this may be because the double-head drive I found has a fault, I've not seriously tested it). I can't use parts of the double head drive to repair the single-head one, the double head drive is conventional with a centre-tapped head, diode switching and no transformer. So what I am looking for is : A new transformer (no chance!). A working or defective-somwehre-else logic PCB (it's labelled 'FC-6' in the silk-screen). No I am not going to try to desolder the transformer >from it (the thing is _very_ fragile), but I could, say, take the microcontroller off my existing PCB if necessary Such a floppy drive with a fault other than in the transformer. Winding details (yes, I am prepared to have go at making one...) And while I'm on the subject, did anyone ever do serious repairs to such drives and have the special tools (compliance-testing weight, alighment pinion driver, etc). I have a load of quesitons on those... -tony

17 years

free/pick-up: Origin 2000 sgi 2400, Tilburg, The Netherlands

by jason＠havnet.net

Ahh but Jules, We know something you dont know !! ... ner ner ... Watch this space for some good news regarding the museum (apart from addition of an SGI Origin 2000 obviously) We had a great time and the Gadget Show Live a few weeks ago See : http://www.computinghistory.org.uk/news/4058/Gadget-Show-Live-2009-Awesome/ which has helped gain us some much needed support ... Anyway, does anyone know where I can get signed drivers for Windows Vista that support the Origin 2000? :-) Jason Curator & Chief Geek The Centre for Computing History -----Original Message----- From: jules.richardson99 at gmail.com Sent: Wed, 29 Apr 2009 16:42:05 -0500 To: cctalk at classiccmp.org Subject: Re: free/pick-up: Origin 2000 sgi 2400, Tilburg, The Netherlands Joost van de Griek wrote: > On Apr 29, 2009, at 20:29, Joost van Baal wrote: > >> The machine will be rescued by the Centre for Computing History >> (www.computinghistory.org.uk) near Cambridge, UK. (It might even get >> hooked up >> on the internet, within a couple of months.) Thanks locutus for help in >> mediating. See http://abramowitz.uvt.nl/sgi.txt for latest status. Knowing that museum, I'm wondering where they're going to put it ;-) (I also believe it'll be well looked after, which is good news) cheers Jules

17 years

home brew S-100 backplane project

by lynchaj＠yahoo.com

home brew S-100 backplane project Doug Jackson doug at stillhq.com Hi Andrew, Could you please put me down for one. I am in Australia, so that has to be factored into the postage. thanks Doug -----REPLY----- Hi! Thanks Doug! I will do that. Shipping overseas would be $5 per PCB. Please contact me offlist so we can discuss further. Two of the eight PCBs available for the initial round of testing are already claimed. I will post pictures of the PCBs and my build progress on the wiki. Thanks and have a nice day! Andrew Lynch

17 years

home brew S-100 backplane project

by lynchaj＠yahoo.com

> -----Original Message----- > From: Andrew Lynch [mailto:lynchaj at yahoo.com] > Sent: Sunday, April 19, 2009 2:29 PM > To: 'cctalk at classiccmp.org' > Subject: RE: home brew S-100 backplane project > > > > > -----Original Message----- > > From: Andrew Lynch [mailto:lynchaj at yahoo.com] > > Sent: Friday, April 17, 2009 10:29 AM > > To: 'cctalk at classiccmp.org' > > Subject: home brew S-100 backplane project > > > > Hi!? I've been working on a home brew S-100 backplane as a side project > [snip] > > Hi! The experimental prototype S-100 backplanes will be available in > about 3 weeks. They will cost $32 each plus shipping which should be $2 > in the US and $5 overseas. All the parts are common and available from > the usual suppliers such as Mouser, Digikey, etc. > > Thanks and have a nice day! > > Andrew Lynch [AJL>] Hi! The S-100 backplane PCBs have arrived. Please contact me if interested in getting one. Thanks and have a nice day! Andrew Lynch

17 years

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test-drb May 2009