test-drb

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101090 discussions

by tshoppa＠wmata.com

Brent wrote: > On 2010 Dec 10, at 2:36 AM, Christian Corti wrote: > > > > we've had a look inside our IME 122 calculator and discovered that it > > is full of SN14xx logic ICs. They are mainly from TI, but there are > > also some from Motorola and others. It seems that they have the same > > function and pinout as the SN74xx parts but there must be a difference > > since the machine has quite a lot of SN1401 (the SN7401 is a quad > > open-collector NAND), but there are no pullup resistors anywhere! > > Some of the types are SN1400, SN1401, SN1474, SN1490; the ALU is made > > up > > of SN1482 and SN1483. > > Anyone knows this series? BTW the supply voltage is 5V. > I can't find a reference for those numbers, and I haven't seen them > before, however I have seen TI inexplicably producing series identical > or similar to more-common series, but numbered differently. For > example, the SN3900 and SN4500 series are very similar to more-common > DTL series such as the 700/800/900 series, but I have never seen a > reference for the 3900 or 4500 series in TI databooks. One suggestion > might be they were a 'consumer-grade' series, a step below the standard > commercial-grade stuff. Remember this was the late 60's or early 70's, and the thought of 7400 as the "super series" with variants like 74L00, 74H00, 74S00 actually being inside the family had not quite taken over in the same sense that it did later, even inside TI. I don't think it's so much that the SN1400's/SN3900's/SN4500's were a step below commercial grade, but they probably had product-specific fanin/fanout/noise/current constraints and maybe even custom pinouts or built-in pullup variants in their specs. The 7400 "super series" of pin compatible parts in different speed/current/fanout levels organized by 74L00, 74H00, 74S00, 74LS00 with often identical pinouts was truly genius from a marketing-meets-technology point of view. Not too different than say the 9-pin dual triode with similar to identical pinouts but different gain variants (e.g. 12AU7/12AT7/12AX7) and a zillion commercial/aerospace/computer variants (e.g. 5814A, 5963, etc.) With regards to pinouts not everyone even inside a company had the same thoughts regarding pin locations for Vcc and gnd. TI did a pretty good job most of the time putting them at 7 and 14 or 8 and 16 for TTL which did simplify layout, but there are lots of exceptions even inside the TTL product space. And sometimes there were good reasons for the exceptions, other times I think it was just internal squabbling :-) You can see some of this playing out in TI's competitors logic families too, e.g. Signetics Utilogic with different subfamilies inside the Utilogic superfamily. Tim.

15 years, 5 months

apple Lisa2. One working!! - one to go?

by dm561＠torfree.net

Date: Sun, 12 Dec 2010 20:32:00 -0200 From: "Alexandre Souza - Listas" <pu1bzz.listas at gmail.com> Subject: Re: apple Lisa2. One working!! - one to go? > However, it's also quite easy to use a 2764 in place of a 2716 in the > actual machine. What I normally do is make an adapter that will plug into > the oriignal EPPROM socket and will tkae the 2764. Most pins just > connect across, you need to connect the higher address lines on the EPROM > to ground (do this on the adapter, of course). Then program the ROM image > into the first section of the larger EPROM, and it should work fine. An example to ilustrate the talk: http://tabalabs.com.br/c64/sx +++++++++++++++++++++++++++++++++++++++++++++++ Definitely interesting and somewhat relevant, but not quite the same thing; that deals with the common problem of replacing 24pin 8K 23xx type ROMs (or 68764/66 EPROMs) with a 27xx equivalent EPROM (with multiple images in this example), whereas Tony was talking about replacing a 2716 with a larger 27xx EPROM, not quite the same thing or adapter. mike

15 years, 5 months

68k s-100 board was [Re Decent Motorola 68000 - 68010 book]

by lynchaj＠yahoo.com

Andrew, The douglasgoodall website required a log in before viewing. Status posted anywhere else? Thanks Rob -----REPLY----- Hi You can check the N8VEM wiki for schematics, PCB layout, and parts list. http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder <http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder&param=S-100%2068K%20 CPU> &param=S-100%2068K%20CPU Otherwise the status of the S-100 68K CPU board is we've got a team of builders schematic captured & reviewed PCB layout done and verified 5 PCB prototypes ordered prototype PCBs sent to builders lead builder is currently doing build and test project wiki set up various pieces of TUTOR 1.3 software gathered We are not done with build and test. No ETA. There are some minor changes and items found so far but nothing of consequence. No cuts and jumpers identified for the board. After prototype build and test is done, we are going to focus on the software. Probably custom test/debug/monitor EPROMs first, then TUTOR 1.3 with a goal of CP/M 68K (maybe) The plan is the PCBs will be available for $20 each plus shipping. They are for educational purposes only. No kits or pre-built boards. There is no ETA for the manufactured PCBs. That's about it. Thanks and have a nice day! Andrew Lynch

15 years, 5 months

Looking For MicroVMS Pre 4.6

by robert.jarratt＠ntlworld.com

Does anyone have any MicroVMS versions pre version 4.6? I'd love to find a version 4.1 if anyone has it. Regards Rob

15 years, 5 months

Happy DEC-10 everyone!

by dseagrav＠lunar-tokyo.net

And remember, if it's not 36 bits, you're not playing with a full DEC!

15 years, 5 months

Check your collections ...

by evan＠snarc.net

This weekend we had a holiday party for MARCH (Mid-Atlantic Retro Computing Hobbyists). At one point last night, several of us walked through our club's storage warehouse. Ian Primus discovered that we have a mostly complete Prime 6550 minicomputer. Apparently its racks have been sitting in our warehouse for five years, but they weren't arranged in the correct order, and I never realized they all go together to make one full system! So, check your collections .... one never knows what one might find among one's own collection after drinking a lot of beer and bourbon.

15 years, 5 months

another question about removing epoxy

by dgahling＠hotmail.com

I read the recent things about removing epoxy or other stuff gunked on components. I have two questions, I have an item with this stuff on it and I want to get it off, however, some of it is covering some of the chips, and I need to be able to identify the components. another worse problem is that one part of the circuit has a SIM card, which is also covered in white epoxy which I want to remove without damaging the SIM card. now the SIM card being encased in plastic means this is a whole lot of "fun" any suggestions?

15 years, 5 months

Decent Motorola 68000 - 68010 book

by lynchaj＠yahoo.com

Decent Motorola 68000 / 68010 book? Keith Monahan keithvz at verizon.net <mailto:cctalk%40classiccmp.org?Subject=Re%3A%20Decent%20Motorola%2068000%20 /%2068010%20book%3F&In-Reply-To=%3C4D059E20.3050300%40verizon.net%3E> Sun Dec 12 22:16:32 CST 2010 * Previous message: Decent Motorola 68000 / 68010 book? * Next message: mysterious 30 pin SIMMs * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ On 12/12/2010 11:15 AM, Philip Pemberton wrote: > Hi guys, > > Does anyone have any recommendations for a good book on the 68000/68010 > CPUs (covering assembly language, the programming architecture and the > interrupt system as a minimum)? -----REPLY----- I like 68000 Microcomputer Systems: Designing and Troubleshooting By Alan D. Wilcox http://www.amazon.com/68000-Microcomputer-Systems-Designing-Troubleshooting/ dp/0138113998 I contacted the author and received permission to make a PCB based on the 68K CPU board in the book. We are making an S-100 68K CPU board PCB based on the board described in the book. It is currently in build and test and the status is on the Douglas Goodall wiki. http://douglasgoodall.pbworks.com There is more information on the N8VEM 68K CPU board on the N8VEM wiki. Thanks and have a nice day! Andrew Lynch

15 years, 5 months

RCS Open House

by wdonzelli＠gmail.com

Mark the 18th of this month - next Saturday - for an Open House at the Retrocomputing Society of Rhode Island* at our millspace in Providence, RI. Last month we fired up an EAI TR-10 analog computer, and I suspect we will be doing the same this month, as well as possibly some work on a PDP-11/45 and a DEC Lab-K. Lots of super nerd geek talk as well. And possibly a fun dog. Generally, hours are 3 to 8 PM, with a dinner break around 6. The mill is located in the neighborhood of Olneyville, just a few miles from central Providence. For directions go to: http://rcsri.org/directions.html Ask if you need more information! *Not the Rhode Island Computer Museum aka RICM! -- Will

15 years, 5 months

Decent Motorola 68000 / 68010 book?

by technobug＠comcast.net

On Sun, 12 Dec 2010 16:15:27 +0000, Philip Pemberton <classiccmp at philpem.me.uk> wrote: > Hi guys, > > Does anyone have any recommendations for a good book on the 68000/68010 > CPUs (covering assembly language, the programming architecture and the > interrupt system as a minimum)? > > [...] > -- > Phil. "Microprocessor Systems Design - 68000 Hardware, Software, and Interfacing" Alan Clements, PWS-Kent Publishing Company It appears that copies are available as PDF downloads from multiple sources... CRC

15 years, 5 months

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