October 2019 - vcf-midatlantic

Museum closing for renovations
by Evan Koblentz 18 Oct '19

18 Oct '19

We're closing the VCF museum during January 2020 to make renovations. This is only our part; InfoAge stays open and they gave us the all-clear tonight. We are discussing various renovation ideas including a new floor (epoxy), better lighting, more signs, exhibit improvements, etc. ... basically all the things I've been talking about but haven't done for the past few years!

1 0

Kennett Classic Opens Today
by Bill Degnan 18 Oct '19

18 Oct '19

Hey all....Karen and I opened a vintage computing exhibit gallery and hobbyist shop which is located in Kennett Square, PA which is more or less between Baltimore and Philadelphia just off Rt 1. We're about 15 miles from I-95 where Delaware meets Maryland. https://www.kennettclassic.com/launch/ It's a big effort, there is still a lot of on-going set up, but starting today at 3PM the doors open and we'd love to see you. We're open 6 days a week, closed Monday. Check out the new exhibits including the Commodore Feature Wall we'll be running through Christmas. We have new vintage computing add-on hardware like Wifi modems and sd storage, plus actual vintage hardware. After this weekend we'll launch our social media (because we'll have pictures). We'll be updating the inventory of what we have for sale on our web site as it comes in, we have a 50 items to add today. We'll also start posting our weekly videocast on the subject of the computer history and vintage computing. busy busy busy! Got to go! Bill Degnan and Karen Doneker kennettclassic.com vintagecomputer.net

2 1

Festivus Tickets
by Jeffrey Brace 17 Oct '19

17 Oct '19

This year I will be selling tickets online through Eventbrite. I am doing this because it makes it far easier for me to manage collection of money for the event. This leaves me more time to enjoy the event and less time tracking down people for money for the event. So I am much happier because I get to enjoy the event more. Tickets for the event are $10 through Eventbrite and $15 at the door. Overnight stay in the Sandy recovery area $25 through Eventbrite and $30 at the door. Click here to buy tickets: < https://www.eventbrite.com/e/festivus-2019-tickets-77436696243?aff=VCFMaili… > Thank you for your cooperation! -- ========================================= Jeff Brace Vice President Vintage Computer Federation

1 0

Introduction
by Kenneth Gober 17 Oct '19

17 Oct '19

Hi, I'm Ken (kgober on the VCF forum). A few months back, when it became increasingly clear that I was missing important local news by not subscribing to this mailing list, I signed up, but I've just been lurking until now. I live in central NJ, and work in IT (Information Security actually) for a large pharmaceutical firm. My interests far exceed the amount of time I have available for them. A big part of my interest in vintage computing is really just an extension of my interest in retro computer gaming, because of course the best platform to run old software on is the hardware it was intended for. I do resort to emulators when I have to; some hardware is just not practical for me to acquire or operate at home (the larger DEC systems, for example). I have a fairly large collection of 8-bit systems that I haven't had time to power on in years, but am unwilling to get rid of. And another fairly large collection of Macs ranging from Mac Plus through G3 that I will someday do something with. Plus of course the PC collection which is mostly Compaq and IBM models (including a bunch of PS/2 systems). Also a few Unix systems (mostly Sun, but a couple IBM RS/6000s too), oldest being a SPARCstation SLC and the newest a SPARC Enterprise T5140. I also have some interest in PDP-11s; I have an 11/23 Micro that I'm trying to get running again (power supply issues) and eventually upgraded to something that will run BSD Unix, and some day I need to get my father's H-11 running again (it's been in storage for decades). I've written some software which I've previously posted about on the VCF forum, notably VT05 and VT52 terminal emulators for Windows, and also "FSX", a command-line utility to browse and read files from old disk images (RT-11, RSX-11, Unix v5, and Commodore for now, with more to be added as time permits). Those can all be found at https://github.com/kgober I've considered attending one of the repair weekends but I can't decide what to actually work on next that's not too much trouble to unearth. The PDP-11 is probably easiest (being on top of the pile) but I do have a TRS-80 Model 4P that needs a new line filter capacitor (at least I think that's what blew up, but I still need to open it up to verify). I have a bunch of Commodore floppy drives that I acquired in 'as-is' condition that need to be checked, but checking a 4040 or 8050 would also require me to dig one of my PETs out of the pile, and I'm not even sure which of them is still working... And so on, and so on. It's kind of a disaster actually. I will certainly have no shortage or projects to work on when I retire, so I've got that going for me. -ken

2 2

A "100%" Efficient BBS Transfer Protocol
by John Heritage 16 Oct '19

16 Oct '19

Hey folks, It always bugged me back in the day that ZModem (and even Ymodem-G) left some performance on the table. For a 14.4 kbps modem with a theoretical perfect transfer rate of 1800 characters per second (assume no data compression, flawless connection, etc) -- ZModem would give you something like 1650-1660 cps and Ymodem-G would give you up to 1730 cps under ideal conditions. Ymodem-G of course had no error recovery (though it did send CRCs to help indicate whether or not there was a problem). In the interest of trying to use 100% of "upload" bandwidth, I always wanted to write a protocol that used the back channel to send CRCs from the 'download' computer to the upload source computer. (Even on asymmetrical protocols like USRobotics standards, 450 bps 'back channel' should be enough for this..) This protocol would operate like ZModem or YModem-G where the uploader just keeps streaming, but no CRCs would be sent with the transfer. Instead, the 'sender' computer would simply pre-calculate CRCs for every 1K or so; the receiver computer would calculate after receiving that 1K, and send back to the uploader. The uploader would go back and verify that it was getting the right CRCs in the right order (you could pre-calculate these and store in RAM before the transfer starts to reduce CPU load during transfer). If no problems were encountered - you might hit that theoretical 1800 cps. If problems were encountered - you'd either pause for some period of time and then re-send the last 3-4 good sets of CRCs to alert the 'receiver' computer that the transfer had to resume from an earlier state and would start after those 3-4 CRC sets were sent. Anyway just some thoughts. Something I might try in C sometime with a couple of modems... John

5 6

Amazing LEGO datacenter model
by Jameel Akari 16 Oct '19

16 Oct '19

I can't stop looking at this amazing thing. https://www.flickr.com/photos/78666052@N05/48569034132/in/dateposted/ "Johan Alexanderson (Jalex) Vintage Computer Room Inspired by computer rooms from the 60s and 70s." The details are just great. -- Jameel Akari

3 3

Museum report (Saturday)
by Evan Koblentz 13 Oct '19

13 Oct '19

I went to the museum yesterday despite taking a break for a while. I needed to pick up the Lego robot stuff for my upcoming Brickfair NJ demo, and also there was an NJIT alumni tour so I figured it's good politics since I work there now. Lots of visitors from the NJIT your and then a few families throughout the rest of the day.

1 0

Museum Report 2019-10-13
by Jeffrey Brace 13 Oct '19

13 Oct '19

A good day at the museum. It started out well with a phone call from the InfoAge front desk to make sure that someone was at VCF because there was a visitor extremely interested in visiting us. It was a 9 year old boy and his family (brother, mother, grandmother) and he wanted to see the original Mac. He had watched YouTube videos, but had never used or touched one. So I let him use MacWrite and MacPaint and Microsoft BASIC. He was high interested and had questions and stayed about an hour looking at other machines. He came from Cape May and I let his mother know about VCF East. There were about half a dozen medium interest people and another half dozen low interest visitors. So overall a good day. -- ========================================= Jeff Brace Vice President Vintage Computer Federation

1 0

Help! Stuck bit
by Dean Notarnicola 09 Oct '19

09 Oct '19

Hey VCF peeps! I’ve got a Briel Altair replica that has a stuck bit on the front panel. I’ve verified that switch (bit) 5 lets me deposit a zero or one into any given memory address. But when I go back to examine it, it always show one regardless of the actual state of the bit. I verified that the switch is good, the led is good, and I replaced all the 74 series latches without effect. There is a 220 ohm resistor in line with it that reads 216 ohm but that should be well within spec for a 5% resistor. I could replace it with a new 2%, but I’m not sure that would fix anything. Anyone have any ideas why this bit always lights when I examine it? Thanks. Dean

2 1

Museum Update
by corey cohen 09 Oct '19

09 Oct '19

We received a lovely donation from Nokia for some improvements in our museum to do more live demos. So Jeff and I figured we can share some of the progress. First, we bought 10 LCD televisions to hook up to the top row of displays where it's impractical to have a vintage monitor. This will allow us to have demos running on machines like our Sol-20, Vic-20, Atari 800 and Tandy CoCo. We also put up an announcement sign in the hallway outside our door. The current video display system (TV) hanging from the ceiling is really missed by many people and until we move it to a better place this will have to do. I also put my youngest son to work scraping our "sign" at the entrance to Infoage because it was peeling very badly. We painted it white with correct outdoor latex paint (I think it was spray painted before with white automobile primer or something). Later in the week we will add reflective lettering that says "Computer Museum". A bit captain obvious, but we are dealing with the public, LOL... We hope to finish this and a few other projects in the next two weeks as we have some parts on order. Here are some pics in a thread I created on our forum. http://www.vcfed.org/forum/showthread.php?71900-Updates-in-progress-at-the-… Cheers, Corey corey cohen uǝɥoɔ ʎǝɹoɔ Vintage Computer Federation, a federal 501c3 designated charity 917-747-1408 mobile corey(a)vcfed.org www.vcfed.org corey cohen uǝɥoɔ ʎǝɹoɔ Sent from my iPhone

2 2