test-drb October 2011

test-drb@ccmp.vtda.org

199 participants
234 discussions

by wrm＠retro.co.za

Hi Etienne and all I remember Leon's name from Stellenbosch days. I recently managed to sign back onto the list -- thanks to whoever was responsible for that. I'm also in Cape Town, and I have some hardware I want to play with and some hardware I realise I will never get around to. The latter includes some Acorn RISC PC stuff, and a vast stash of BBC stuff. Two actual computers, and lots and lots of software and a few books. The only HP I have is an HP-85. Anybody else here from South Africa?

13 years, 1 month

QBUS PDP 11's available free in Yorkshire (UK)

by silvercreekvalley＠yahoo.com

Hi, I discovered some more QBUS PDP 11 machines in an old storage unit I'm emptying. These machines are the rack mount style QBUS PDP 11's, and appear to be intact, although their disk drives have been removed. They all have CPU and memory. These are collection only from Yorkshire - but free of charge. I have 3 machines available and possibly some spare cards. These need to be collected next week unfortunately. Any interest email me directly. Thanks Ian.

13 years, 1 month

Spreadsheets (was Microsoft flamage)

by mtapley＠swri.edu

At 3:22 -0500 10/24/11, Tony wrote: >There probably is a need for an 'engineer's spreadsheet' with proper >complex number support, but I guess the market is much less than for >'business' applicatiosn which only need real numbers. Mathematica can do that functionality, but probably not cost-effectively and not (current versions) on legacy hardware. (Mma v. 1 is included in NeXTStep 1.0, so if you can get that optical media together with a working optical drive (good luck there!) you are set). I have not tried MathCad, Maple, macsyma, etc., and at least the last one of those is on-topic and should run on the classes of machines (VAX-11/780, etc.) that might be found around Casa Duell. I have got (but sadly have not tried yet) a copy of muMath which might be able to do it on a DEC Rainbow. muMath's successor Derive (DOS/Windows) became the basis for the TI Nspire CAS, and early versions of that might also serve in this context. Has anyone got experience with doing complex arithmetic in any of these? -- - Mark 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

13 years, 1 month

Reading Amstrad PCW floppies on a PC

by lproven＠gmail.com

I've bought a copy of LocoScript 4 (or so) to run on my PCW9512+. However, I'd also like to get it running under the Joyce emulator on my PC. How might I read a PCW floppy into a PC disk image? It's a 3.5" 720 DD disk. My PC does have a 3?" drive and runs Windows 7/64 and Ubuntu 11.10/64. I possibly have an ancient copy of 22copy somewhere, but it runs under DOS which at the mo' my PC is not configured to boot... :( -- Liam Proven ? Info & profile: http://www.google.com/profiles/lproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AIM/Yahoo/Skype: liamproven ? MSN: lproven at hotmail.com ? ICQ: 73187508

13 years, 1 month

Spreadsheets (was Microsoft flamage)

by jonas＠otter.se

On Wed, 19 Oct 2011 21:42:03 +0100 (BST), ard at p850ug1.demon.co.uk (Tony Duell) wrote: > Did/does any spreadsheet, on any platform, allow you to put complex > numbers in the cells and operate on them? > > Yes, of course you can treat a complex numner as 2 real numbers and > define the appropriate operations -- any spreadsheet will do that. I did > it in Visicalc. But as I use complex numbers a lot in AC circuit > analysis, and I know others who do too, I am suprised no spreadsheet > handles them as well as my HP calculators. Surprise surprise, apparently Excel will let you work with complex numbers. It seems you have to install the "Analysis Pak" (which apparently is supplied with Excel, see e.g. http://office.microsoft.com/en-us/excel-help/load-the-analysis-toolpak-HP00… for the 2003 version). That of course doesn't mean that it handles them as well as your HP calculators :-) /Jonas

13 years, 1 month

Kaypro-II video section

by elazzerini＠interfree.it

The computer-Kaypro II had a 9" green phosphor monochrome monitor composed of a LR30477 E39164 TOSHIBA CRT and a printed circuit steering Toshiba TLC-134-TV-0. I tried to supply it with 12Vdc and I noticed that the cathode of the CRT is lit, while the screen does not turns on and no shows light even using the knob back adjustment for the light intensity. Wishing to do TV repair technician I need the wiring diagram of the circuit electric drive Toshiba TLC-134-T-V-0. Is there someone who has it? Here some pictures: http://elazzerini.interfree.it/Kaypro-II/Foto2026.html http://elazzerini.interfree.it/Kaypro-II/Foto2018.html <http://elazzerini.interfree.it/Kaypro-II/Foto2019.html> http://elazzerini.interfree.it/Kaypro-II/Foto2019.html http://www.flickr.com/photos/67772736 at N07/sets/72157627837488485/ . Unfortunately I did not notice on the board (component side) or under the card (solder side) no sign of burning. I seem to hear at the power on of the CRT an high-frequency hiss. Having found the power supply of the Kaypro-II not working and not knowing whether it is the motherboard, I was first trying to see if the CRT works. As a signal source I am using the monochrome output of a PC 8088 XT video card because the kaypro-II accepts distinct signals: video, Hsync and Vsync. It could be not true that the polarities of these signals are useful as a signal generator to test the video section of Kaypro-II. Any suggestions would be great. The schematic much more. Enrico

13 years, 1 month

Fixed point financial data versus floating point - Re: Spreadsheets (was Microsoft flamage)

by vintagecoder＠aol.com

The same thing can happen in COBOL. All the guys when I started on IBM knew the native data types and which ones to use for what. A few years ago somebody asked me to give a training session to some guys who had 2 to 8 years with COBOL on IBM and nobody in the room (about 15 people) had any idea about anything, not one of them ever opened an IBM manual. Lucky for them and their employer, they never actually wrote any code, they just cut and pasted and were using packed decimal for money. ------Original Message------ From: Fred Cisin Sender: cctalk-bounces at classiccmp.org To: General Discussion: On-Topic and Off-Topic Posts ReplyTo: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Fixed point financial data versus floating point - Re: Spreadsheets (was Microsoft flamage) Sent: 24 Oct 2011 19:38 On Mon, 24 Oct 2011, Vintage Coder wrote: > Agreed. It's not floating point (no mantissa/exponent) and the user has > complete control over the decimal point, which is imaginary as far as > the representation goes. There is no decimal point in the data, only > digits and a sign. The name "packed decimal" seems like a safe way to > differentiate it from floating point while giving a hint to the internal > representation (two digits to a byte). As most everyohne here knows, the 80x85 family has some minimal support for both packed and unpacked BCD. But the lack of a widely known data type using those in C and BASIC results in way too much software being written with inappropriate data types, such as "float".

13 years, 1 month

Fixed point financial data versus floating point - Re: Spreadsheets (was Microsoft flamage)

by vintagecoder＠aol.com

Agreed. It's not floating point (no mantissa/exponent) and the user has complete control over the decimal point, which is imaginary as far as the representation goes. There is no decimal point in the data, only digits and a sign. The name "packed decimal" seems like a safe way to differentiate it from floating point while giving a hint to the internal representation (two digits to a byte). ------Original Message------ From: Fred Cisin Sender: cctalk-bounces at classiccmp.org To: General Discussion: On-Topic and Off-Topic Posts ReplyTo: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Fixed point financial data versus floating point - Re: Spreadsheets (was Microsoft flamage) Sent: 24 Oct 2011 19:11 On Mon, 24 Oct 2011, Vintage Coder wrote: > Decimal math (hardware supported) is used heavily in financial > processing with IBM COBOL. No loss of precision because the type is base > 10. BCD is very similar to what IBM calls "packed decimal". Although with a radix of 10, which MAKES SENSE for financial, I still think of that as being scaled integers. It is not an exponential structure like the IEEE Floating Point Representation Standard.

13 years, 1 month

Integer pennies (was: Re:Spreadsheets)

by john＠yoyodyne-propulsion.net

On Mon, Oct 24, 2011 at 3:53 PM, Mark Tapley <mtapley at swri.edu> wrote: > How will they ever get rich moving the rounded-down fractional pennies into > their own accounts? If you do that you'll end up in Federal "Pound you in the Ass" prison. -- Yoyodyne Propulsion Systems: ?"The Future Begins Tomorrow" Visit us at: http://www.yoyodyne-propulsion.net -------- "If a free society cannot help the many that are poor, it cannot save the few who are rich." -John F. Kennedy

13 years, 1 month

HP 13181B Tape Interface

by etienne＠tlabs.ac.za

Hi All, I'm a nuclear scientist and serial hobbyist out in Cape Town, South Africa. I'm helping a friend restore some old HP machines. We have a 13183 Interface set to swap for a 13181B Tape Interface. We will also happily pay for it and cover the shipping costs to wherever you are. As a point of interest, we are also currently restoring a MITRA 125. If anyone has any info on this machine we'd really appreciate it. Best Regards Etienne Vermeulen and Leon Heinkelein

13 years, 1 month

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test-drb October 2011