test-drb

test-drb@ccmp.vtda.org

101090 discussions

by tshoppa＠wmata.com

Al writes: > Tim writes: >> I fully expect that his archive is a large collection of 8", 5.25", and 3.5" floppies. > In the system.txt file, there are quite a few ".zip" files listed. Yes there are, but those are not Don's speciality, which was CP/M boot disks. The zip files I gave to Don tended to be things like BIOS source files, disassemblies, etc. Probably true for others too. Often these were closely associated with a particular system or boot disk. Don never made the leap to "disk image" being the central focus. Possibly With good justification because he supported many non-FM/non-MFM formats (GCR, hard sectored, etc.) that teledisk et al did not handle. Tim.

13 years, 5 months

OSCAR [was RE: Big Alphas (was Re: FS: HP AlphaServer DS15)]

by RichA＠vulcan.com

From: Ethan Dicks Sent: Friday, November 16, 2012 9:25 AM > One interesting historical note - it was formerly OSCAR, the card > catalog computer for the Ohio State University library system. Wow. I remember when OSCAR was maintained on the administrative IBM System/370 over in that building north of the library. The VAX was not even a design idea yet, of course, when I first met OSCAR. (I worked in the library from September 1973 to August 1975, first on the shelving crew and after 1 quarter at the circulation desk. When I told my Stanford students later that programming paid better than shelving books at the library, I knew what I was talking about.) Rich Alderson Vintage Computing Sr. Systems Engineer Vulcan, Inc. 505 5th Avenue S, Suite 900 Seattle, WA 98104 mailto:RichA at vulcan.com mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/

13 years, 5 months

discrete transistor computer

by elson＠pico-systems.com

There are several discrete transistor computers posted on the net, some with complete schematics. http://hackaday.com/2012/04/20/building-a-computer-with-discrete-transistor… There was a German (possibly Dutch?) guy that made a discrete transistor computer using all one kind of SMT transistor and other SMT components on PC boards, it was the size of a shoebox. I can't find the link now. Jon

13 years, 5 months

Don Maslin collection status

by fjkraan＠xs4all.nl

On 2012-11-15 23:41, mc68010 <mc68010 at gmail.com> wrote: > the names of all the disks are limited to eight characters. That would > sort of indicate they were files on something. The two images of the list I got from Don were TD0 files, TeleDisk image files. EPSNQX10.TD0 and EPSNVLDC.TD0. They came in a zip EPSQX.ZIP. Some extra, 'unsorted' zips were EPSQX-B.ZIP, EPSQX-D.ZIP and EPSQX-E.ZIP. Fred Jan

13 years, 5 months

Has anyone heard from Dave Dunfield?

by aek＠bitsavers.org

I tried sending a message to him at the dave12 address and didn't hear anything back then I noticed he hasn't posted anything here since March.

13 years, 5 months

IBM PC replica

by brain＠jbrain.com

Is this old news: http://www.mtmscientific.com/pc-retro.html -- Jim Brain brain at jbrain.com www.jbrain.com

13 years, 5 months

discrete transistor computer

by ed.spittles＠gmail.com

On 29 Apr 2012 at 18:46, Richard Smith wrote: > This thread reminds me of a computer we built at school from discrete > transistors. Each transistor was a NOR gate with three resistors on > the base and a collector resistor. All soldered onto squares of tag > board. We put a bunch of them together to build a shift register with > small laps as output. That would be about 1969 or 1970. Does anyone > remember any more? It must have been a published design somewhere. Richard, I think I read the book this project was based on - in the school library, mid-to-late 70's. I've been looking for it, but my recollection is so vague I haven't found it yet. I think it may have kicked off with some physical computing based on wood and ball bearings, but anyhow it worked up to a full serial CPU. My searches have been based on the recollection that the author was Wilkinson (but maybe Wilkins, Watson, Wilson, Watkins, Watkinson, ...) and, of course, it might not even have starte with W. Any info about your school or the specific teacher might help track it down. Or maybe someone here can remember it? Cheers Ed

13 years, 5 months

Drool!!!

by robert.jarratt＠ntlworld.com

http://www.ebay.com.au/itm/Digital-DEC-VAX-11-750-mainframe-vintage-retro-co mputer-not-PDP11-microvax-/251180977499?pt=AU_Computers_Vintage&hash=item3a7 b8d8d5b Regards Rob

13 years, 5 months

Midwest show: C4 2013

by silent700＠gmail.com

The C4 Commodore show, held every summer near Cincinnati, Ohio, did not happen this year due to lack of funds. The loyal Commodore scene doesn't want to make it two years in a row, so they are experimenting with pre-funding the show this time around: https://www.crowdtilt.com/campaigns/c4-expo-2013 For this iteration they will be following the model set by Chicago's VCFMW/ECCC and opening their show up to all sorts of vintage computing, as well as extending the event to two days. The tentative date is the weekend of June 8, 2013. Like our show, no admission will be charged, but any donations are greatly appreciated. At this time I am not part of the planning process for the show but I do plan to make a donation and, work schedule permitting, attend. Questions should be directed to the contact address on the page above. >From what I've heard, the venue alone is worth the trip. (Also the USAF Museum at Wright-Patterson AFB, which I have been to, can easily eat up a whole day.) -- silent700.blogspot.com Retrocomputing and collecting in the Chicago area: http://chiclassiccomp.org

13 years, 5 months

Ton of IMSAI stuff in New Mexico...

by bdamer＠digitalspace.com

Dear CC folk, The DigiBarn received this note from someone who is trying to handle the proper dispensation of a ton of IMSAI stuff located in Albuquerque NM (not Ohio). Read on below and feel free to get directly in touch with him... ### I am in the process of clearing the estate of Gary W. Harris who opened the first computer store in Columbus, OH in about 1975. He was an IMSAI dealer. I have IMSAI equipment, including an 8080, many S-100 boards, and manuals for boards and for IMSAI equipment. Still going through stuff. There is so much stuff, and I don't want to go the EBay route with all the posting, packaging and sending. Can you advise on the disposal of this material in a way that will be to the mutual advantage of the recipient and Gary's estate. Contact: davharr at q.com ###

13 years, 5 months

Tracometer and BAC levels (was: Re: mystry cards make offer or they going in trash :()

by Arno_1983＠gmx.de

On Nov 11, 2012, at 1:25 AM, mc68010 wrote: >> The testing on that device appear to have be brutal unless I am >> reading wrong. They made the subject test it at 1.2% BAC. I wonder >> how many died. Wouldn't they all ? >> >> http://pro.sagepub.com/content/31/7/751 > (...) isn't > greater than .50% generally at high risk for alcohol poisoning? > > - Dave Yes, .5% is considered "usually lethal" and probably even attainable only for the most extremely alcohol-tolerant persons (anybody else is bound to either have to go puke or pass out long before that) and/or by means of specialized consumption techniques (co-consumption of mar-jah-wana is said to suppress puking). > Um, yeah. At first I thought it was a typo, but they have similar > concentrations elsewhere and give the correct mg/L, so... Nope, it *is* methinks a typo. They're mixing up percents (%) (which is the usual parameter given for ABV in alcoholic beverages) and promille (o/oo) which is the usual unit of measurement for BAC, at least in Germany. 1 Percent is "one part of a hundred" whereas 1 Promille is "one part of a thousand", so 10 Promille make 1 Percent. The given mg/l concentration supports that (they're simplifying insofar that they calculate with a density of 1 g/ml for the blood sample), as 1200 mg/l or 1.2g/l or(about) 1.2g / 1000g is 1.2 *thousandth* (=Promille) or 0.12 % BAC (and not 1.2 % as given in the text), which makes a lot more sense for the average intoxicated person. Just my 2 o/oo... Yours sincerely, Arno Kletzander

13 years, 5 months

old tv's and CRT's

by gerhard.kreuzer＠liftoff.at

Hi Chuck, NTSC ... Never The Same Color Gerhard -----Urspr?ngliche Nachricht----- Von: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] Im Auftrag von cctalk-request at classiccmp.org Gesendet: Samstag, 10. November 2012 19:00 An: cctalk at classiccmp.org Betreff: cctalk Digest, Vol 111, Issue 25 Send cctalk mailing list submissions to cctalk at classiccmp.org To subscribe or unsubscribe via the World Wide Web, visit http://www.classiccmp.org/mailman/listinfo/cctalk or, via email, send a message with subject or body 'help' to cctalk-request at classiccmp.org You can reach the person managing the list at cctalk-owner at classiccmp.org When replying, please edit your Subject line so it is more specific than "Re: Contents of cctalk digest..." Today's Topics: 1. Re: P112 question - what can you run that uses 1MB of RAM? (Alexandre Souza - Listas) 2. Re: old tv's and CRT's (ben) 3. Re: P112 question - what can you run that uses 1MB of RAM? (ben) 4. Re: P112 question - what can you run that uses 1MB of RAM? (Alexandre Souza - Listas) 5. Re: old tv's and CRT's (Chuck Guzis) 6. Re: P112 question - what can you run that uses 1MB of RAM? (allison) 7. Re: P112 question - what can you run that uses 1MB of RAM? (Alexandre Souza - Listas) 8. Re: P112 question - what can you run that uses 1MB of RAM? (ben) 9. Re: Disk drive manuals (Cameron Kaiser) 10. Laser printers, was Re: P112 question - what can you run that uses 1MB of RAM? (Dave McGuire) 11. PC-1/CX cartridge compatibility, was Re: P112 question - what can you run that uses 1MB of RAM? (Dave McGuire) 12. Re: Wanted: Research Inc. Teleray terminals (Ethan Dicks) 13. Re: P112 question - what can you run that uses 1MB of RAM? (allison) 14. Re: P112 question - what can you run that uses 1MB of RAM? (Mouse) 15. Sam's Computerfacts 4851 Disk Drive (Chris Tofu) 16. Re: P112 question - what can you run that uses 1MB of RAM? (Roger Pugh) 17. Re: P112 question - what can you run that uses 1MB of RAM? (Roger Pugh) 18. Re: P112 question - what can you run that uses 1MB of RAM? (Roger Pugh) 19. Re: P112 question - what can you run that uses 1MB of RAM? (ben) 20. Re: Networking a Macintosh SE/30 (Joost van de Griek) 21. Needed - rear brackets for BA23 mounting kit (Jack Rubin) 22. Re: To Metcal, or not to Metcal? Re: RepRapping. Was:Re: Restoring an Intel SDK-86 to "mostly like new" condition (Jochen Kunz) ---------------------------------------------------------------------- Message: 1 Date: Fri, 9 Nov 2012 22:30:11 -0200 From: "Alexandre Souza - Listas" <pu1bzz.listas at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <5A3297F6A7834D649F33D6EB0E3AA0B0 at tababook> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response > Tell me what toner does a P112 use or is that used to color the 1MB of > ram?? Well, a 64-K CPM system will not print raster graphics with ease on a Laser Printer...You need more RAM! :oD Well, at least I tried :D ------------------------------ Message: 2 Date: Fri, 09 Nov 2012 17:40:56 -0700 From: ben <bfranchuk at jetnet.ab.ca> To: cctalk at classiccmp.org Subject: Re: old tv's and CRT's Message-ID: <509DA298.8030607 at jetnet.ab.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/9/2012 4:17 PM, Chuck Guzis wrote: > At any rate, between 1950 and 1953, the official color television > standard in the USA was the CBS field-sequential system, which, > compared with the RCA system of the same time was quite good (at least > for the time)--a mechanical 3-color filter was spun in front of the > CRT, synchronized to a similar filter at the camera. > > It wasn't until 1953 that RCA had improved its system well enough for > NTSC color to become the official standard. > > A few CBS System receivers still exist. Lots of vintage TV's still can be found. It is getting working color CRT's that are the problem from what I read on the net. Now might be the last time to find CRT's for vintage computer equipment. > --Chuck Has the color on modern display devices matched the color purity of the early TV's yet? Ben. ------------------------------ Message: 3 Date: Fri, 09 Nov 2012 17:50:49 -0700 From: ben <bfranchuk at jetnet.ab.ca> To: cctalk at classiccmp.org Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DA4E9.3020107 at jetnet.ab.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/9/2012 5:30 PM, Alexandre Souza - Listas wrote: >> Tell me what toner does a P112 use or is that used to color the 1MB of >> ram?? > > Well, a 64-K CPM system will not print raster graphics with ease on > a Laser Printer...You need more RAM! > > :oD > > Well, at least I tried :D > Well if you could access the toner drum directly from the host cpu, I am sure you could emulate a generic mono-spaced printer like a TTY in 16K including the printer fonts. Ben. ------------------------------ Message: 4 Date: Fri, 9 Nov 2012 22:59:27 -0200 From: "Alexandre Souza - Listas" <pu1bzz.listas at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <792C68D6371B41E29AFE93C46BE4CEB5 at tababook> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response >> Well, a 64-K CPM system will not print raster graphics with ease on >> a Laser Printer...You need more RAM! > Well if you could access the toner drum directly from the host cpu, I am > sure you could emulate a generic mono-spaced printer like a TTY in 16K > including the printer fonts. I doubt. And you woudn't print raster graphics :) ------------------------------ Message: 5 Date: Fri, 09 Nov 2012 17:07:22 -0800 From: Chuck Guzis <cclist at sydex.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: Re: old tv's and CRT's Message-ID: <509DA8CA.9080005 at sydex.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/09/2012 04:40 PM, ben wrote: > Has the color on modern display devices matched the color purity of the > early TV's yet? If you're talking about 1950s RCA/NTSC sets, then the answer is no--modern displays were much better. I vividly remember one of the first families on the block to get color TV around 1957. It was an RCA set--the color was greenish and the reds had a longer persistence than the other phosphors, so red objects would "smear" badly on a dark background. Really, NTSC was terrible when it was new and didn't improve all that much. --Chuck ------------------------------ Message: 6 Date: Fri, 09 Nov 2012 20:15:10 -0500 From: allison <ajp166 at verizon.net> To: General Discussion: On-Topic Posts Only <cctech at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DAA9E.2010702 at verizon.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/09/2012 07:50 PM, ben wrote: > On 11/9/2012 5:30 PM, Alexandre Souza - Listas wrote: >>> Tell me what toner does a P112 use or is that used to color the 1MB of >>> ram?? >> >> Well, a 64-K CPM system will not print raster graphics with ease on >> a Laser Printer...You need more RAM! >> >> :oD >> >> Well, at least I tried :D >> > > Well if you could access the toner drum directly from the host cpu, I > am sure you could emulate a generic mono-spaced printer like a TTY in > 16K including the printer fonts. > Ben. > Actually no. To do that you need to be able to process the data rapidly enough to lay down dots as the drum rotates. The key thing for Laser printing (or any page printer) is the bit image need to exist before the paper moves or at least be preprocessed so that the raster image processor can fill a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM engine) was about 7mhz. The early character only version use a 12mhz 80186 with 8089 to keep up, The system IO to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based engine was not much slower on the video clock. In the late 80s there were two lasers often those that were band buffer and generally limited to text and limited graphics and a higher priced version that had enough ram to buffer the page so the image could be composed before the paper was even moved. Actually I use my CP/M-80 system to lay down images on a real Laserjet4L. The price is that I need to run the system for a long time to create bit images to transmit. That takes hours even with ram and bit of buffering to hard disk. Even then the printer is doing much of the heavy lifting. The main issue was never ram but CPU cycles to process that data at acceptable rates for graphic images. It is the same issue as doing video graphics on a CRT or LCD. In that case you need enough ram to buffer the image for refresh and enough cpu to create and transfer images to that ram. So to simply move bytes to a 1MB page buffer it would take a Z80 at 4mhz around 8 seconds with no processing other than simple paging. That's too slow. Allison ------------------------------ Message: 7 Date: Fri, 9 Nov 2012 23:39:16 -0200 From: "Alexandre Souza - Listas" <pu1bzz.listas at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <F8B4613B967146C7AEA1AC774F475533 at tababook> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response > Actually no. To do that you need to be able to process the data rapidly > enough to lay down dots > as the drum rotates. > ... I love this list, I learn more and more every day :o) ------------------------------ Message: 8 Date: Fri, 09 Nov 2012 18:41:58 -0700 From: ben <bfranchuk at jetnet.ab.ca> To: cctalk at classiccmp.org Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DB0E6.6040001 at jetnet.ab.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/9/2012 6:15 PM, allison wrote: > On 11/09/2012 07:50 PM, ben wrote: >> On 11/9/2012 5:30 PM, Alexandre Souza - Listas wrote: >>>> Tell me what toner does a P112 use or is that used to color the 1MB of >>>> ram?? >>> >>> Well, a 64-K CPM system will not print raster graphics with ease on >>> a Laser Printer...You need more RAM! >>> >>> :oD >>> >>> Well, at least I tried :D >>> >> >> Well if you could access the toner drum directly from the host cpu, I >> am sure you could emulate a generic mono-spaced printer like a TTY in >> 16K including the printer fonts. >> Ben. >> > > Actually no. To do that you need to be able to process the data rapidly > enough to lay down dots > as the drum rotates. That is a mechanical issue, not the idea of charging a drum with a laser. The old, cheaper hardware, faster software problem here. I don't think software has yet to solve the real problem of modern printers, is that text on the screen does NOT match the printed page, but that is off topic. > The key thing for Laser printing (or any page printer) is the bit image > need to exist before > the paper moves or at least be preprocessed so that the raster image > processor can fill > a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM > engine) was about 7mhz. > The early character only version use a 12mhz 80186 with 8089 to keep up, > The system IO > to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based > engine was not much > slower on the video clock. In the late 80s there were two lasers often > those that were > band buffer and generally limited to text and limited graphics and a > higher priced version > that had enough ram to buffer the page so the image could be composed > before the paper > was even moved. I think history of Time-Sharing computers had a big impact here. You needed BIG fast page laser printer to share between users, so high speed printer was needed. Speed I don't think changed much over the years, but build quality HAS dropped. > Actually I use my CP/M-80 system to lay down images on a real > Laserjet4L. The price is that > I need to run the system for a long time to create bit images to > transmit. That takes hours > even with ram and bit of buffering to hard disk. Even then the printer > is doing much of the > heavy lifting. Custom software, or using a driver for a text processing package? > Allison > Ben. ------------------------------ Message: 9 Date: Fri, 9 Nov 2012 17:42:39 -0800 (PST) From: Cameron Kaiser <spectre at floodgap.com> To: cctalk at classiccmp.org Subject: Re: Disk drive manuals Message-ID: <201211100142.qAA1gdBn30408900 at floodgap.com> Content-Type: text/plain; charset=US-ASCII > > VERY little interest in books. And these are some of the better ones. > > WhatamI gonna do when I get down to the boxes of Sybex books and crappy > > books on WordPerfect? > > Build a fort and throw AOL CDs at people passing by? I like the floppies. They have those nice metal edges which make a ragged laceration if you get the right spin on 'em. -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- Use foresight, and pessimism. ---------------------------------------------- ------------------------------ Message: 10 Date: Fri, 09 Nov 2012 21:20:32 -0500 From: Dave McGuire <mcguire at neurotica.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: Laser printers, was Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DB9F0.2000206 at neurotica.com> Content-Type: text/plain; charset=ISO-8859-1 On 11/09/2012 08:41 PM, ben wrote: >> The key thing for Laser printing (or any page printer) is the bit image >> need to exist before >> the paper moves or at least be preprocessed so that the raster image >> processor can fill >> a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM >> engine) was about 7mhz. >> The early character only version use a 12mhz 80186 with 8089 to keep up, >> The system IO >> to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based >> engine was not much >> slower on the video clock. In the late 80s there were two lasers often >> those that were >> band buffer and generally limited to text and limited graphics and a >> higher priced version >> that had enough ram to buffer the page so the image could be composed >> before the paper >> was even moved. > > I think history of Time-Sharing computers had a big impact here. You needed > BIG fast page laser printer to share between users, so high speed > printer was > needed. Speed I don't think changed much over the years, but build > quality HAS dropped. The build quality for consumer crapware has dropped, but if you buy that stuff, you get what you deserve. I had a DEC LN01 for a long time. It was a cantankerous beast but it was built like a tank. (I would love to have one again, if anyone has one lying around) Today's GOOD printers are built every bit as well. -Dave -- Dave McGuire, AK4HZ New Kensington, PA ------------------------------ Message: 11 Date: Fri, 09 Nov 2012 21:22:01 -0500 From: Dave McGuire <mcguire at neurotica.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: PC-1/CX cartridge compatibility, was Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DBA49.6000708 at neurotica.com> Content-Type: text/plain; charset=ISO-8859-1 On 11/09/2012 06:00 PM, Fred Cisin wrote: >>> . . . and the lab staff at the college (25 years ago) found out that if >>> you fill the copier cartridge with printer toner, and then try to use it >>> in the copier, it produces a very poor quality reverse video image. > On Fri, 9 Nov 2012, Tony Duell wrote: >> I wonder whathte physical explanation for that is. > > The only explanation that I was given was: > "The company selling the refill kit (Torx driver, page of instructions, > bag of toner) sent the wrong toner." If memory serves, the drum coating was a completely different composition, it was even a different color. -Dave -- Dave McGuire, AK4HZ New Kensington, PA ------------------------------ Message: 12 Date: Fri, 9 Nov 2012 22:23:32 -0500 From: Ethan Dicks <ethan.dicks at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Wanted: Research Inc. Teleray terminals Message-ID: <CAALmimnXUWH=3g+dWLLZXRJcUk+jLjAhDx9JNd_9tRDzgP8fBQ at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 On Tue, Mar 13, 2012 at 4:37 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote: > On Tue, Mar 13, 2012 at 2:24 PM, Eric Smith <eric at brouhaha.com> wrote: >> Richard wrote: >> I wrote about Teleray terminals: >> >>> I'm not sure which model, but it was reportedly 6502-based, and had some >>> kind of hacked firmware installed. > > Are there any photos of the PCBs out there? I have a small box of > what appear to be 6502-based terminal boards with lots of socketed > TTL. I do not know the vendor, but I can look for distinctive > markings. I never had the terminals. I just picked up a box of > "random" boards from a Hamfest some time ago. I found one of the boards tonight... It's really hard to read the hand-written scrawl on the label, but it certainly _could_ be 1061. The board has several DB25s on one edge, a prominent pair of 9114 SRAMs, what looks like a ROM in one corner (if 8316 is a part number for a 2K masked-programmed ROM), and I think it attaches to the video circuit with a two-row 0.1" ribbon cable of about 20 pins. There are a pair of side-toggle dip-switches on one edge for what looks like configuration settings. I did a bit of googling for the Teleray 1061 and about all I found out is that it was released in 1978 for around $1100 and there are some quirks with it enough to get mentioned in termcap comments. I did not find schematics or a proper manual. When I got it, I didn't know what it was and I got it for the socketed parts. If anyone is trying to fix a Teleray 1061, this could be your lucky day. The chips on it are worth a few dollars to me as spares but not a vast amount. I already have more dumb terminals that I could ever use, so I see no reason why I'd ever try to turn this board into a working terminal. If someone wants it, contact me off-list, otherwise, it'll stay in the parts bin for now. -ethan ------------------------------ Message: 13 Date: Fri, 09 Nov 2012 22:29:31 -0500 From: allison <ajp166 at verizon.net> To: General Discussion: On-Topic Posts Only <cctech at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509DCA1B.80209 at verizon.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/09/2012 08:41 PM, ben wrote: > On 11/9/2012 6:15 PM, allison wrote: >> On 11/09/2012 07:50 PM, ben wrote: >>> On 11/9/2012 5:30 PM, Alexandre Souza - Listas wrote: >>>>> Tell me what toner does a P112 use or is that used to color the >>>>> 1MB of >>>>> ram?? >>>> >>>> Well, a 64-K CPM system will not print raster graphics with >>>> ease on >>>> a Laser Printer...You need more RAM! >>>> >>>> :oD >>>> >>>> Well, at least I tried :D >>>> >>> >>> Well if you could access the toner drum directly from the host cpu, I >>> am sure you could emulate a generic mono-spaced printer like a TTY in >>> 16K including the printer fonts. >>> Ben. >>> >> >> Actually no. To do that you need to be able to process the data rapidly >> enough to lay down dots >> as the drum rotates. > > That is a mechanical issue, not the idea of charging a drum with a laser. You are not serious. The drum rotates slowly but each line of pixels is the length of the printed area (8") times the 300line per inch of the circumference and at 8PPM the average drum in small printers turned several times to print the whole 11 inchs. It's a raster scan system. Character printers could compose at a rate that was one cell height at a time so they use band buffers that often allowed typically 8 or 16 lines on the drum to be buffered at a time while the next lines were being processed. That scheme was good to a point but there were pathological cases that resulted in page to complex and imaging failures. often overstrikes were the likely culprit. For 8PPM that means moving 7920000 pixels in about 7.5 seconds without much dead time. You cannot stop the drum during the process. The laser does not charge the drum, it's used to discharge it, you can do it with LEDs as well but they were slow back then. The typical cycle is charge corona, writing (laser, or led raster scan), developing (toner) transfer(transfer corona) and cleaning (discharge corona sometimes), and doctoring (scrape the remaining toner off with a silicone rubber blade). Repeat as eneded. Polarities and what optical range this are done are dependent on if the drum was selenium coated or the organic photoreceptor that Cannon wrapped the cartridge around. > > The old, cheaper hardware, faster software problem here. I don't think > software has yet to solve the real problem of modern printers, > is that text on the screen does NOT match the printed page, but that > is off topic. That belongs back with one of the threads that had NAPLPS in it or maybe WYSIWYG when WYGINS is the reality. No one prints at under 100 DPI. Maybe now with very high resolution color displays we see what we get but then the best CRT I ran in color was 1280x1024 and .27 dot pitch (about 70-80dpi) which is still coarse by then 300DPI standard. That meant the tube could not display (even in B&W) what the printer could. New we have displays that are easily better than 300dpi but printers can do 600dpi and maybe more. That doesn't even cover color. > >> The key thing for Laser printing (or any page printer) is the bit image >> need to exist before >> the paper moves or at least be preprocessed so that the raster image >> processor can fill >> a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM >> engine) was about 7mhz. >> The early character only version use a 12mhz 80186 with 8089 to keep up, >> The system IO >> to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based >> engine was not much >> slower on the video clock. In the late 80s there were two lasers often >> those that were >> band buffer and generally limited to text and limited graphics and a >> higher priced version >> that had enough ram to buffer the page so the image could be composed >> before the paper >> was even moved. > > I think history of Time-Sharing computers had a big impact here. You > needed > BIG fast page laser printer to share between users, so high speed > printer was > needed. Speed I don't think changed much over the years, but build > quality HAS dropped. > No build quality is better. We ( I was part of the team that developed the LN01, LN03 and LPS40 and LPS20 series at DEC) found that getting engines that could run at speed for 90 days without breakdown was a mechanical impossibility, we had customers prove it repeatedly. Back then the choices were Cannon, Ricoh, Xerox and in about that order of durability. Getting 200,000 to 300,000 pages between failure was the challenge and price was the other. To get to 40PPM (LPS40) a microVAX in the printer pushing a custom bitslice processor and a even more custom bitbliter so that a reasonably complex page set could be printed at 40PPM. That's what it took then. But the printer took postscript directly and printed up to B size pages with no page too complex issues. Now we have cheap fast cpus that can do that. This development was in the time frame of the "workstation" so the big VAX in the back was not always the factor. However the cost of even slow printers was high enough Then that shared resource was what the customer said. The price of a 8PPM printer then is far higher than a 20ppm color printer now. So the existence of timesharing was and is a red herring as big systems printers printed less graphics and small single users wanted all the printing capability.. Often the single user was a workstation of even then a PC with Hercules or early CGA video. >> Actually I use my CP/M-80 system to lay down images on a real >> Laserjet4L. The price is that >> I need to run the system for a long time to create bit images to >> transmit. That takes hours >> even with ram and bit of buffering to hard disk. Even then the printer >> is doing much of the >> heavy lifting. > Custom software, or using a driver for a text processing package? > Very custom, in assembler as excess overhead was painful and I had one of the uncommon 10mhz z80s. I did it mostly to prove a point but waiting hours per page was not practical. Doing hi res text only documents was easy and people were doing it tot he limits of what printers were available. Graphics just wanted more of everything by many orders of magnitude. Large ram was cost and speed issues but doable then. Code can overcome a lot of things but raw CPU speed was and is the prime solution (enter GPUs). FYI I still run that LJ4L as its durable and parallel interfaces to all my systems directly save for the latest PC with no IO save for USB ( PIC24 programmed for USB to parallel solution). Allison ------------------------------ Message: 14 Date: Fri, 9 Nov 2012 23:14:03 -0500 (EST) From: Mouse <mouse at Rodents-Montreal.ORG> To: cctalk at classiccmp.org Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <201211100414.XAA23825 at Sparkle.Rodents-Montreal.ORG> Content-Type: text/plain; charset="iso-8859-1" > I don't think software has yet to solve the real problem of modern > printers, is that text on the screen does NOT match the printed page, I don't think that - to the extent it _is_ a problem - _can_ be solved, as long as printers are higher-resolution than displays. (Not unless you artificially cripple the printout to match the display's resolution, at least.) > but that is off topic. Well, to a point. Some classic machines had display resolutions close to their printer resolutions, and the two _could_ match fairly well.... /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B ------------------------------ Message: 15 Date: Fri, 9 Nov 2012 20:36:21 -0800 (PST) From: Chris Tofu <rampaginggreenhulk at yahoo.com> To: "cctalk at classiccmp.org" <cctalk at classiccmp.org> Subject: Sam's Computerfacts 4851 Disk Drive Message-ID: <1352522181.91090.YahooMailNeo at web141104.mail.bf1.yahoo.com> Content-Type: text/plain; charset=us-ascii Need it. Anyone have it? Hook me up, ay/. ------------------------------ Message: 16 Date: Sat, 10 Nov 2012 10:39:21 +0000 From: Roger Pugh <rogpugh at mac.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509E2ED9.7040701 at mac.com> Content-Type: text/plain; CHARSET=US-ASCII; format=flowed On 10/11/2012 01:15, allison wrote: > On 11/09/2012 07:50 PM, ben wrote: >> >> >> Well if you could access the toner drum directly from the host cpu, I >> am sure you could emulate a generic mono-spaced printer like a TTY in >> 16K including the printer fonts. >> Ben. >> > There was a laserprinter available for i think the Atari ST (or later model) that did away with the processor and and used the atari. This cut the cost of the printer down to about 1000 pounds/dollars which was very cheap in its time, esp when compared to the apple laser.. I think it was a canon engine. This idea was used in the "windows only" laser printers where the ripping was done on the PC and the raw data sent to the printer via parallel port. Roger ------------------------------ Message: 17 Date: Sat, 10 Nov 2012 10:45:57 +0000 From: Roger Pugh <rogpugh at mac.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509E3065.3 at mac.com> Content-Type: text/plain; CHARSET=US-ASCII; format=flowed On 09/11/2012 19:45, Tony Duell wrote: >> . . . and the lab staff at the college (25 years ago) found out that if >> you fill the copier cartridge with printer toner, and then try to use it >> in the copier, it produces a very poor quality reverse video image. > I wonder whathte physical explanation for that is. > > -tony Pretty much every type of printer or copier uses different photoreceptor/toner/developer/carrier. As these all work on electrostatic priniples things such as charge, spacing between components, materials used in consumables, fusing temps are all different. 11 years working at Xerox, 12 more years on toner based digital printing... Roger ------------------------------ Message: 18 Date: Sat, 10 Nov 2012 11:18:19 +0000 From: Roger Pugh <rogpugh at mac.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509E37FB.7050505 at mac.com> Content-Type: text/plain; CHARSET=US-ASCII; format=flowed On 10/11/2012 01:15, allison wrote: > > Actually no. To do that you need to be able to process the data > rapidly enough to lay down dots > as the drum rotates. > > The key thing for Laser printing (or any page printer) is the bit > image need to exist before > the paper moves or at least be preprocessed so that the raster image > processor can fill > a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM > engine) was about 7mhz. > The early character only version use a 12mhz 80186 with 8089 to keep > up, The system IO > to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based > engine was not much > slower on the video clock. In the late 80s there were two lasers > often those that were > band buffer and generally limited to text and limited graphics and a > higher priced version > that had enough ram to buffer the page so the image could be composed > before the paper > was even moved. I am a tech at a company called XEIKON. We manufacture color digital presses.. We print on rolls of paper of upto 50cm (20inch) at 1200DPI at speeds of 19 meters a min (about 60ft/min??). The presses are 5 colour on both sides.. Being roll fed presses we cant stop the press and wait for the data, LOTS of FPGA's are required to keep up the data stream. We are low end industrial, some of the expensive stuff like Kodaks Prosper of course need lots more.... Roger ------------------------------ Message: 19 Date: Sat, 10 Nov 2012 08:41:04 -0700 From: ben <bfranchuk at jetnet.ab.ca> To: cctalk at classiccmp.org Subject: Re: P112 question - what can you run that uses 1MB of RAM? Message-ID: <509E7590.3070405 at jetnet.ab.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 11/9/2012 9:14 PM, Mouse wrote: >> I don't think software has yet to solve the real problem of modern >> printers, is that text on the screen does NOT match the printed page, > > I don't think that - to the extent it _is_ a problem - _can_ be solved, > as long as printers are higher-resolution than displays. (Not unless > you artificially cripple the printout to match the display's > resolution, at least.) > >> but that is off topic. > > Well, to a point. Some classic machines had display resolutions close > to their printer resolutions, and the two _could_ match fairly well.... Well not resolution issue, but font scaling. Windows seems to have lost TrueType somewhere on my machine. For what little C programing I do, fixed with fonts is what I want! Ben. PS. If people were happy with printer output, programs like TeX would not be here. ------------------------------ Message: 20 Date: Sat, 10 Nov 2012 17:50:02 +0100 From: Joost van de Griek <gyorpb at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Networking a Macintosh SE/30 Message-ID: <802939B0-23D9-4074-99A4-29D786921F3C at gmail.com> Content-Type: text/plain; charset=us-ascii On 9 Nov 2012, at 23:41 , Schindler Patrik <poc at pocnet.net> wrote: > Am 09.11.2012 um 20:46 schrieb Tony Duell: > >>> I recall the same thing. >> And o yet again Apple did not adhere to an accepted standard.... > > Yes, because the monitor port on Macs already had been DB15-F, years before Macs with Onboard-Ethernet came to life. Apple was eager to keep setting up Macs as easy as possible. That includes distinct connectors for distinct functions. Size was also a consideration. Standard AUI connectors would ill fit on PowerBooks. .tsooJ -- There are perhaps 5% of the population that simply can't think. There are another 5% who can, and do. The remaining 90% can think, but don't. - Robert A. Heinlein -- Joost van de Griek <http://www.jvdg.net/> ------------------------------ Message: 21 Date: Sat, 10 Nov 2012 09:02:15 -0800 (PST) From: Jack Rubin <jack.rubin at ameritech.net> To: classiccomp list <cctalk at classiccmp.org>, Ed Groenenberg <quapla at xs4all.nl>, Philipp Hachtmann <hachti at hachti.de> Subject: Needed - rear brackets for BA23 mounting kit Message-ID: <1352566935.26136.YahooMailRC at web181304.mail.ne1.yahoo.com> Content-Type: text/plain; charset=us-ascii I'm racking a BA23 system into a corporate cabinet, using a BA23-AR mounting kit. I have the rails, front brackets and front cover but I'm lacking the rear brackets that secure the rails to the rear cabinet posts. Apparently some racks require these brackets and some don't. I have _three_ racking kits and none of them have the rear brackets. The brackets are short pieces of sheet metal, about 2" deep and 3" high. They are bent in a shallow U shape with an extended tab on one leg. Part numbers are 7428372-01 and 7428372-02 (left and right sides). They are shown in the BA23 Enclosure Maintenance manual, p 2-22. Please let me know if you can spare a pair (or more) of these items. Thank you, Jack ------------------------------ Message: 22 Date: Sat, 10 Nov 2012 18:43:57 +0100 From: Jochen Kunz <jkunz at unixag-kl.fh-kl.de> To: cctalk at classiccmp.org Subject: Re: To Metcal, or not to Metcal? Re: RepRapping. Was:Re: Restoring an Intel SDK-86 to "mostly like new" condition Message-ID: <20121110184357.52697ee564c856131a1e998a at unixag-kl.fh-kl.de> Content-Type: text/plain; charset=US-ASCII On Thu, 01 Nov 2012 16:27:25 -0400 Dave McGuire <mcguire at neurotica.com> wrote: > If you end up getting one, > I'd appreciate knowing what you think of it. The Oki MFR-2241 arrived today. I did some (de-) soldering on scrap PCBs in the last hours. It is amazing how the small 1 mm chisel cartridge heats up large through hole pins soldered to big ground planes. My old iron wolud not be able to do this, in no way. The OKi tips are thin and short. Wheres the heater + tip of my old iron is much thicker and longer. A touch up on a single SMD pin is much easier with the OKi, as the total length of the tip is much shorter. The "precision" tweezers aren't that precise as expected, but its OK. Wane desolder that SO8? Grab with the tweezers, wait a second or two and it comes off. Wane desolder that LM2676 (dPak)? Tin the leads for better heat conduction, grab with the tweezers, wait some more seconds (large ground plane under the chip) and it comes off... My setup cost me 830 EUR (approx. 1055US$) including some tips. The single PSU variant, MFR-1100, is 300 EUR (approx. 380US$). If you are in buissines for a new soldering iron and can spend that much money, get at least a MFR-1100. It is worth every single cent! I'll get a pair of larger tips for the tweezers later. These are expensive, around 100 EUR. But desoldering a DIP16 or the like will be a piece of cake with them. p.s. At unpacking I noticed that the pacel had been droped top down onto the flor. But the PSU survived without a single scratch. It is build out of cast aluminium. It is heavy and build like a tank. Its really industrial grade equipment. -- \end{Jochen} \ref{http://www.unixag-kl.fh-kl.de/~jkunz/} End of cctalk Digest, Vol 111, Issue 25 ***************************************

13 years, 5 months

Unusual PC hardware and EPROMS for sale

by clemfm＠gmail.com

Hi Jim, I've seen your 386 card on ebay and whilst looking for drivers came across your post here: http://classiccmp.org/pipermail/cctech/2012-October/137378.html I'd take both the 386 and 68020 cards, however drivers are an issue as I can't seem to locate them on the web or newsgroups etc. Any luck finding them at your end? Regards Clem

13 years, 5 months

P112 question - what can you run that uses 1MB of RAM?

by ethan.dicks＠gmail.com

Hi, All, I'm not joining in the kickstarter because I already have a P112 I purchased as a bare PCB and loose SMD parts in the previous round. I just uncovered it last night moving some things around and started tossing build-parts into a bin to put it together. I do happen to have a couple of 32-pin JEDEC 512K SRAMs (originally for an SBC6120 RAM disk PCB that got destroyed in the mail), so I _can_ fully populate it, but it got me wondering... what CP/M software is out there (except maybe a RAM disk) that can *use* 1MB? I have a bit of experience with 48K-64K CP/M machines (mostly Kaypro, but some others), because back when I was using it, that was how much memory 8-bitters had. I didn't mess with them much after 1985, so if there was still any development on that platform, I didn't see it. So why *does* the P112 have 1MB of RAM? What's the space over 64K good for? Cheers, -ethan

13 years, 5 months

cctech Digest, Vol 111, Issue 21

by francois.dion＠gmail.com

> From: Tom publix <ittybittybytes at gmail.com> > I'll be putting some apollo stuff up and maybe some other stuff later this > week. Of course, mention your a member of the ccmp list and get some > freebies thrown in. I posted a few weeks back: I'm looking for a DN1000, or similar era (pre HP). Do you have anything like that? Fran?ois -- solarisdesktop.blogspot.com - raspberry-python.blogspot.com

13 years, 5 months

4 bit cpu with 74xx

by francois.dion＠gmail.com

Someone built a 4 bit cpu using 74xx series chips: http://dangerousprototypes.com/2012/11/01/7400-competition-entry-fourbit-4-… Fran?ois -- solarisdesktop.blogspot.com - raspberry-python.blogspot.com

13 years, 5 months

Networking a Macintosh SE/30

by dgriffi＠cs.csubak.edu

I think I have my head wrapped around the hardware tuneups that my Mac SE/30 requires. Moving on to the software. I've found install media and can get System 6 installed just fine. I can read and write HD floppies in my Linux box to move things in and out by sneakernet. I'm having a nasty time getting the ethernet board to work. I'm using an Asante MacCon PSD slot ethernet board. I downloaded the driver pack (still at Asante's website), made a driver install disk, and installed the driver stuff. This installs a driver for the board, ethertalk, and MacTCP. A diagnostic program on the disk says that the ethernet board is checking out fine, but I can't get the machine to talk or listen to the network. It's not at all clear how the MacTCP panel is supposed to be used. I've tried following http://www.applefool.com/se30/ and nothing works (though I can't get the Legacy Recover CD referred to there). Is there someone on this list who has done this before who can help me? -- 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?

13 years, 5 months

P112 kits now with parts

by dgriffi＠cs.csubak.edu

I did some number crunching and decided that I can indeed produce P112 kits with all the parts you'll need. See http://661.org/p112 or http://p112.feedle.net -- 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?

13 years, 5 months

Mac Stuff including HyperDrive Install

by rrissell＠gmail.com

Hi all, I'm Robyn and I'm a computer pack-rat... "Hi Robyn!" I'm doing some cleanup at the behest of the wife and have some vintage gear to get to a new home. Anything is available for pickup or for the price of shipping. (Pickup is preferred as vintage rotating media does not like un-parked shipping) 1. Hyperdrive 2.0 install (used - condition unknown - SEEMS to be all there with drive and install binder, driver for Mac available online) 2. Powerbook 160 installed in a Powerbook 140 case (greyscale, operational, Lead-Acid batteries in condition you'd expect). (MAY be able to find the original MB for PowerBook 140, was a display cable issue) 3. Mac HD-20 external HD for Mac Plus (operational with installed system) 4. Apple External SCSI CD drive (the big long one, includes HD-30 cable and terminators) 5. Copy of MacIntosh 68000 development system with disks 6. Copy of MacIntosh, Lost Treasures of Infocom 7. Printed copy of MacIntosh User's Guide + HyperCard Manual 8. Mac SCSI IOMEGA ZIP drive (with P/S and 3 new Mac Formatted ZIP disks) 9. Mac 800K external drive 10. Misc Mac Plus mice, keyboard, microphone and Phone-Net dongles 11. Floppies and other Misc as I find them. Robyn rrissell at gmail.com Lake Orion, MI

13 years, 5 months

P112 kickstarter success

by dgriffi＠cs.csubak.edu

I just thought you'd all be interested to hear that my P112 Kickstarter project has been successfully funded. Now for the formalities of getting the money transferred to me and I can start buying parts. -- 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?

13 years, 5 months

Liberator: the untold story of the first British laptop

by lproven＠gmail.com

Part One: Taking over the typing pool By Tony Smith ? Get more from this author Posted in Hardware, 12th November 2012 12:01 GMT Feature In 1985, the UK home computer boom was over. Those computer manufacturers who had survived the sales wasteland that was Christmas 1984 quickly began to turn their attention away from the home users they had courted through the first half of the 1980s to the growing and potentially much more lucrative business market. The IBM PC had been launched four years earlier, in 1981. The 5150 and the clones it had inspired at Compaq and other computing firms new and established were winning an increasing share of the market. Some British manufacturers were content to follow the American lead and offer clones of their own. Others, however, believed they could win with systems of their own design. [...] http://www.theregister.co.uk/2012/11/12/the_secret_history_of_liberator_the… -- Liam Proven ? Profile: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven Tel: +44 20-8685-0498 ? Cell: +44 7939-087884

13 years, 5 months

NMOS 6502 internals

by jules.richardson99＠gmail.com

Just looking at some 6502 stuff, and the program counter notes at http://www.6502.org/tutorials/6502opcodes.html#PC say: "When the 6502 is ready for the next instruction it increments the program counter before fetching the instruction." ... which seems to imply that T-cycle 0 of an instruction first increments PC, then fetches the opcode from the memory location pointed to by PC. Which seems nuts, as it would also mean that either jump addresses would have to be off by 1, or at the start of T0 the CPU would have to determine what the _previous_ instruction was and then either increment PC or leave it alone accordingly. And all of this would have to happen before the address is placed on the address bus approximately 1/4 of the way into T0. I expect that what actually happens is that PC's contents are latched onto the address bus during the clock-low half of T0, R/W is asserted, and *then* PC is incremented. During the subsequent clock-high half of T0, the data bus will reflect the contents of [PC] as it was at the start of T0, and the PC increment will complete, so that at the end of T0 PC is pointing to either an operand byte for the current instruction, or the next instruction in the sequence (if the current instruction has no operands). Can anyone confirm? Although technically I suppose the text on the site would still be accurate, because the increment would actually have begun before the fetch had entirely completed, but the way it reads to me is that the opcode fetch happens at [PC+1], not [PC]... The text then goes on to say: "Once it has the op code, it increments the program counter by the length of the operand, if any." 6502 operands can be 1 or 2 bytes in length; the above seems to imply that for a 2-byte operand it would add 2 to PC - meaning it would have to fetch the first operand byte from PC-1 (and there's no PC-decrement logic in sight). I expect that what it really does is fetch the first byte from PC (which will have been incremented during the opcode fetch cycle), increments PC by 1, fetches the second byte, and increments PC again. Right? :-) Now, someone on the BBC micro list said they think that the 6502 might always do an operand byte fetch immediately after an opcode fetch, even if that instruction doesn't have any operand data - simply because it takes time for the CPU to decode the instruction. If it turns out that the instruction doesn't have an operand, it avoids doing the PC increment that would have been done if an operand were present (which means that at the next cycle, which the CPU will perform as an opcode fetch, the same byte is re-read from memory and interpreted as an instruction). Does anyone know if this "always read" is what happens? Or is the instruction decoding actually quick enough for the CPU to know by the end of T0 that there's no opcode data (and so it can reset its cycle counter and perform the next cycle as an opcode fetch)? cheers Jules

13 years, 5 months

Differences between KFQSA submodels

by robert.jarratt＠ntlworld.com

I have come a across someone selling two different KFQSA boards. Is there a significant difference between a KFQSA-SG-RE and a KFQSA-SF-RE? Regards Rob

13 years, 5 months

More Shameless classic parts trafficking

by ittybittybytes＠gmail.com

Hi everybody! More shameless classic parts trafficking. These go live on 11/12/ @ 2pm on epay 251183147655 DEC 11/04, dual sms floppy drives, Vt100 and rt-11 251183206220 DEC tm03 controller unit I'll be putting some apollo stuff up and maybe some other stuff later this week. Of course, mention your a member of the ccmp list and get some freebies thrown in. Cheers tom

13 years, 5 months

Ohio Scientific Challenger 1P video

by terry＠webweavers.co.nz

Some of you may know of this item already but some may not, and might be interested. It's a short 10min YouTube video on one of the units in my collection: An OS Challenger 1P http://youtu.be/zrOYkKf5Y5k Terry Stewart (Tez)

13 years, 5 months

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