test-drb April 1999

test-drb@ccmp.vtda.org

170 participants
1190 discussions

by CLASSICCMP＠trailing-edge.com

>C= PET VisiCalc EPROM >--------------------- >The Commodore PET version of the VisiCalc spreadsheet came with a chip that >plugged into a socket on the main board. This was probably an EPROM, used for >copy-protection. I have an original VisiCalc package, minus this EPROM. Does >anyone know where I can download an image of the EPROM from? I'd be interested to know exactly what this chip did. It was never perfectly clear to me that it was used for copy-protection. >Nutspinner >---------- >Disassembling PCB-mounting D-type connectors is a pain without having a >nutspinner for the hexagonal bolt things which typically fix the connector to >a panel. What size, number or whatever nutspinner is the right one for this >purpose? 3/16 inch. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 2 months

Lisp, the machine language. Was Re: Hallelujah!

by allisonp＠world.std.com

<>They are micro-coded to run LISP, sorta like the WD P-Engine machines run <>PASCAL. < <So, an assembly language program for them would look like lisp, as opposed <to MOVs, ADDs, and so forth? And same with Pascal? But why would anyone <want something that was microcoded to run Pascal? Are there any other <languages that have gotten microcoded into a processor? Pascal was never microcoded, the P-interpreter was microcoded on one system. The difference is significant. The P-engine was a theorhetical stack machine that Pascal would optimally compile to. The idea was everything above the P-engine level would be standard code and only the P-engine would ahve to be rewritten for each different processor (which is why it was on PDP-11, Z80, 6502 to name a few). Allison

25 years, 2 months

homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

><ISA cards on a single s-100 board. This would certainly be cheap enough i ><most cases, to warrant such an effort. The software might get to be a ><problem, though. >Yes, and therein lies the "problem" for the average user. This is why I prefer simple serial console. No software to write, no memory mapped video to take a chunk out of usable memory, no memory banking schemes, no dependence on finding monitors of a particular scan rate or interface. Just a simple I/O port! Admittedly, many folks seem to believe that a computer must have a video generator to be a "computer". My CP/M experience started with Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd man out here. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 2 months

homemade computer for fun and experience...

by edick＠idcomm.com

please see imbedded comments below. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 11:47 AM Subject: Re: homemade computer for fun and experience... ><have something concrete in mind, too. If one inserts a wire-wrap 62 pin ><(8-bit ISA) connector into a DIN 41612 right-angle socket, such as what on ><finds on a VME wire-wrap board, but of opposite gender, (remembering that ><once sold S-100 wire-wrap boards with a pattern certainly suitable for thi ><purpose, and VME wire-wrap cards as well) one can, indeed, host two 8-bit > >Been there and done that. >Also, there are no less than two articles on how to go from s100 to ISA. > There's a substantial reach from an article to a solid and working circuit on a board capable of actually supporting the functions. This is particularly true since, now, the user is required to understand the inner workings of his own machine as well as those of the card he wishes to use. Having the usual inkling about ISA is not always sufficient. ><ISA cards on a single s-100 board. This would certainly be cheap enough i ><most cases, to warrant such an effort. The software might get to be a ><problem, though. Yes, and therein lies the "problem" for the average user. >What software problem... since s100 cards tend to be all different anyway >it would be the norm that software would have to be created. > >Allison >

25 years, 2 months

RLV11/RL02 ->11/73?

by allisonp＠world.std.com

<I've done it useing a RLV12 board set though. As far as I know it can't b <done with the RLV11 you have. At least I was given to understand that if <you try you'll let out the magic smoke. I'e done it with both using the correct backplanes. As I remember the SMS1000 is a bit strange in the boot deperatment. <If you're wanting to boot off of RL02's then remember that you'll want to <have something with boot roms that support the drives. The only thing I <have that does is a /23+ My 11/73 boots RL02 (both unix V7 and RT11). Allison

25 years, 2 months

RLV11/RL02 ->11/73?

by CLASSICCMP＠trailing-edge.com

>> Some options for UNIBUS have a U as the second or third of >> the option name... dhU, dU. But generally, the UNIBUS options >> are two-character names, DL, DH, DZ, VT, etc... As always, there >> are exceptions, like DUP, DMC, DMR... >Is there a guide somewhere that explains what all the codes translate to? Ron Copley's venerable "Field Guide to Q-bus and Unibus Modules" contains, in most cases, the option name as well as the module number in the description. For example: M8053-AA DMV11 Q Microprogrammed controller (needs one of M5930- M5931) (Also M8053-AB, -AC, -ETC) Generally, a "D" at the front means it's some sort of communications option, a "M" means memory, a "K" means CPU, "R" means disk controller, a "T" means a tape controller, an "A" means an A/D or D/A converter, a "V" means some sort of video-related hardware, and "L" means either a line printer or a linear module. I'm sure someone will come up with many options that don't quite fit into this scheme :-). The field guide claims at its top: *This list may always be found on sunsite.unc.edu, in the following *directory: */pub/academic/computer-science/history/pdp-11/hardware/field-guide.txt *(Tonnes of stuff here... thanks, Tim!) -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 2 months

Lisp, the machine language. Was Re: Hallelujah!

by CLASSICCMP＠trailing-edge.com

>the WD Pascal microengine. Why was it done? In the late 70s Pascal was >emerging as a teaching language and it was highly standardized. Most >small systems had the resources to run it as native compiled but the >authors (UCSD) decided that portable Pcode would allow more platforms >to run it as the Pengine was easier to code than a whole compiler. Not only that, but the P-code was often more compact than the equivalent native machine code. (It's probably even more compact than modern RISCy processor code.) Compactness of code is an enormous advantage in a limited memory-space environment. Tim.

25 years, 2 months

Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>Actually, I thought they had microcode or assmebly language. Therefore, >they have a compiler to create the microcode or assembly language. It may >not be well-documented (or advertised) but it's there. > >-- Derek This is a mistaken impression. Actually, microcode is not compiled. For any computer which is microprogrammed, there is a sequence of microinstructions which implements each executable statement of the computer. In the case of the Lisp machine (such as those built by Symbolics - like the 3600), the machine instructions are, in fact, the operators of Lisp. So, there is within the microcode of a List machine a sequence of microinstructions which implements directly the function of a Lisp operator, such as CAR. As it happens, it is easily possible for any of use to obtaine the so-called MacIvory, which is a Lisp machine that operates within the MacIntosh computer. It is a co-processor much like the i860 based board that I bought several years back from MicroWay. The i860 is a single chip implementation of the Cray-1, (you know, Harvard archetecture, and the like), and provides just about the same throughput as the Cray-1. An old high-school buddy of mine worked for Symbolics, and today does Lisp programming at Moffett Field for NASA Ames. He is quite well acquainted with the microcode of the 3600, and it is upon his instruction that I became equally familiar. William R. Buckley

25 years, 2 months

Computer busses....

by allisonp＠world.std.com

<This reminds me of the Intersil 6100 which had a special "front panel" mod <designed to hold code and data to run the (presumably flashy) front panel. Same for the 6120 (has EMA interally). IT was presumed due to the micros lack of front pannel you would need startup code or emulation code. <would be getting a 6100). I did the design/layout/prototype of a 6100 CPU They can be found especially the 6120 version. If not a DECMate is a good source(they are hardly rare). Allison

25 years, 2 months

bringing up an 8f...

by allisonp＠world.std.com

<>> Put boards (all but core) and regulator board in dishwasher and <> dried them in the oven. < <Eek! Really? Does this work? Yep. In the past (over 20 years ago) I used to do it in the sink with a bristle paint brush and some liquid soap. <Were these just the power supply boards, or all of the OMNIBUS <boards too? All but the core plane and front pannel itself. The little cores would not like the blasts of water pusing them around. I didn't want the switches washed out as then I'd have to get some lubricant back into them. I've done this with all sorts of boards to get gunk off them and it's basically how boards are cleaned at factory. HINT, keep the temps below 200f. <I recently got a PDP8/E system (it runs well), with 16K core and <8K solid state memory, and it's really grubby inside, and I've been <thinking about how to clean it all up. Can you share some secrets <on the settings used, ie: do you use any soap in the dishwasher? I put it in and ran standard cycle (short wash). The CORE planes do not ever go in and also if there are switches that can trap water special care may need to be taken. Things must be dry before power up or electrolisys and other bad things happen. Pure water is generally harmless. Soap, I used one of the standard products that seems to work well on glasses. Allison

25 years, 2 months

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test-drb April 1999