test-drb May 2001

test-drb@ccmp.vtda.org

273 participants
642 discussions

Mac Portable (Was Re: Seriously OT: Firearms)

by jhellige＠earthlink.net

>Can we get back ON TOPIC and talk old computers, such as how to coax a dead >mac portable to power up? I have one and can get a cracking sound out of the >speaker but nothing else. Also, try this page for some additional info: http://www.geocities.com/SiliconValley/Heights/3959/index.html Jeff -- Collector of Classic Microcomputers and Video Game Systems: Home of the TRS-80 Model 2000 FAQ File http://www.geocities.com/siliconvalley/lakes/6757

23 years, 2 months

o-scope

by ajp166＠bellatlantic.net

From: Jim Strickland <jim(a)calico.litterbox.com> >> Probe compensation is off or the amplifier (vertical) are misadjusted >> internally. > >Ookay, how do I fix this? Is there an adjustment screw inside? And if so, >any recommendations on what not to touch so I live through the experience? :) Touch nothing. You require the manual and some aid/experience in adjusting something like the vertical amp. FYI there is serious HV inside scopes. Be careful. Allison

23 years, 2 months

o-scope

by ajp166＠bellatlantic.net

From: Jim Strickland <jim(a)calico.litterbox.com> >So I'm a 'scope newbie, does the probe impedance (13 pf) have to match the >rating on the jack on the scope (47 pf) for the waves coming out of the >calibration jack to be properly square? And if so, does anyone have a source >for probes that work with ancient scopes like this? No not required to match. That specification is the capacitance presented across the input jack along with the scopes input resistance (usually 1megohm). Most scope probes have an adjustment to compensate for this and therefor it's not a problem. >Other than the waveform distortion (at worst the square waves wind up looking >like shark teeth, and at best they're a bit sloped on the leading and top >edges) the scope seems to work fine as far as I can tell. Probe compensation is off or the amplifier (vertical) are misadjusted internally. A square wave on that series should look square. Allison

23 years, 2 months

How many transistors in the 6502 processor?

by ajp166＠bellatlantic.net

I'd heard, four bits in four packages. Allison -----Original Message----- From: Fred Cisin (XenoSoft) <cisin(a)xenosoft.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Sunday, May 06, 2001 3:26 PM Subject: Re: How many transistors in the 6502 processor? >On Sun, 6 May 2001, Mike Ford wrote: >> My guess is that 68000 as a name had a lot to do with adding a zero to 6800. > >I have been told several times that the 4004 was named after being the >equivalent of 4004 transistors. I don't believe that. But what WAS the >origin of the name? > >

23 years, 2 months

o-scope

by jim＠calico.litterbox.com

It's not a computer, but it's surely over 10 years old... I got a scope today, a Tektronix either a 535a or 545a according to the operator's handbook in the little hidey hole in the top of the case. (which I'll gladly scan if anyone wants a copy). So I'm a 'scope newbie, does the probe impedance (13 pf) have to match the rating on the jack on the scope (47 pf) for the waves coming out of the calibration jack to be properly square? And if so, does anyone have a source for probes that work with ancient scopes like this? Also, how do I tell a 535a from a 545a? Other than the waveform distortion (at worst the square waves wind up looking like shark teeth, and at best they're a bit sloped on the leading and top edges) the scope seems to work fine as far as I can tell. Also, can anyone recommend a good book on scope use for newbies? -- Jim Strickland jim(a)DIESPAMMERSCUMcalico.litterbox.com ----------------------------------------------------------------------- BeOS Powered! -----------------------------------------------------------------------

23 years, 2 months

Interesting show on the Computer Garage

by Lee.Davison＠merlincommunications.com

> England doesn't allow guns, and look at the mess they're in. Huh? What mess? > Guns kill plenty of people, sure. Guns don't kill people, people with guns kill people. Lee. ---------------------------------------------------------------------------- ---- This email is intended only for the above named addressee(s). The information contained in this email may contain information which is confidential. The views expressed in this email are personal to the sender and do not in any way reflect the views of the company. If you have received this email and you are not a named addressee please delete it from your system and contact Merlin Communications International IT Department on +44 20 7344 5888. ________________________________________________________________________ This message has been checked for all known viruses, by Star Internet, delivered through the MessageLabs Virus Control Centre. For further information visit: http://www.star.net.uk/stats.asp

23 years, 2 months

+ and - on HP21 calculator?

by cmcmanis＠mcmanis.com

Hi, I've got an HP-21 that is missing the battery pack. Does anyone know which pin is plus and which minus when you look at the calculator from the back, with the AC adapter plug facing up? I can probably synthesize a battery pack with a couple of AA NiCd cells but wouldn't want to hook it up backwards. There are two contacts at the "back" of the battery box for the cells and it would be useful to know this info ... --Chuck

23 years, 2 months

How many transistors in the 6502 processor?

by ajp166＠bellatlantic.net

From: Davison, Lee <Lee.Davison(a)merlincommunications.com> > >I've never heard of mos-multi-emitter-transistors > >Just etch multiple mos structures and have a common gate. Tie drains and >sources as required. > >Lee. Very common, also devices were split and run in parallel as two smaller devices were faster or had better characteristics then one larger one. On silicon designs rarely translate to discrete beyond the early parts. Allison

23 years, 2 months

Allison: 2910c version of z80 and FPGAs - a little O/T

by ajp166＠bellatlantic.net

From: Richard Erlacher <edick(a)idcomm.com> >rather, the old solid 8's or 11's. Emanuel once told me there are a couple of >makers of PDP-11 look-alikes that work well enough to be of interest. Like the Mentec, they have the license and make cpu/systems to go with the OS. Some are quite fast compared the the 1978 gold standard (PDP-11/70). >From the other standpoint I can easily fine PDP-11/23s and even 11/73 or 11/83 series machines making the effort somewhat moot. People have done PDP-8s for "lab projects" for years and at least one was packed in to two arrays (cpu, memory and IO!) on a board small enough to barely hide a 3.5" drive. The problem is PDP-8 is not a rom friendly design from the start. PDP-11 is better there but much of the stuff out there wants for RAM, excluding the unique code for the Falcon and later class SBCs. Allison

23 years, 2 months

For Sale: DEC System 5000 Memory Boards

by markn＠mr2.net

hi Folks... i have 8 memory boards salvaged from a DECSystem 5000, each board contains 78 TC511000AJ-10 chips (39 on each side). These are untested, although they came from a working system and have been kept in anti-static bags since removal. please email me with offers, i'm in the UK so i'd prefer to sell them only in the UK... although i will ship internationally if it's worth it. there's a picture of a board at: http://www.daneel.demon.co.uk/auctionimages/decmemory.jpg many thanks mark ======================= Mark Nias http://www.mr2.net http://www.marknias.com =======================

23 years, 2 months

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test-drb May 2001