March 2017 - vcf-midatlantic

Applesoft game programming
by Evan Koblentz 04 Mar '17

04 Mar '17

I had an idea for a game. You'd use the joystick to control the physical Lego robot against on-screen challenges such as places you must hit and other places (evil robots) you must not hit, within a certain time, in order to win. There would be penalties for going out-of-bounds (colliding with the square around the screen). I never wrote a BASIC game. This is a first for me. I figure it's a good idea to start by determining some (ahem) "basic" concepts. After all I'm using the extent of 7th-grade formal programming education combined with 30 more years of brainpower + improved understanding of programming logic. Starting by keeping it simple: sticking with Applesoft's lo-res mode. I already knew the screen is 0 through 39 horizontally/vertically (40x40) in lo-res mode. And I knew the joystick goes 0-255 each way. So, I figured 256/40 is 6.4, so if I divide the status of paddle 0 or 1 by 6.4 then I can say that's my plot point, right? Time for a science experiment... I came up with this: 10 X=PDL(0) : Y=PDL(1) 20 X=X/6.4 : Y=Y/6.4 Then I realized some positions would give me remainders. No good. Googled for how to round off numbers and discovered Applesoft's INT command. Also found a tip explaining that INT rounds off * no matter what the decimal may be *, so the trick is to always add 0.5 before doing the INT function. Okay, that makes sense. 10 X=PDL(0) : Y=PDL(1) 20 X=X/6.4 : X=X+0.5 30 Y=Y/6.4 : Y=Y+0.5 40 PRINT INT(X), PRINT INT(Y) : REM (so I get numeric confirmation in the bottom text area of the screen) 50 GR:COLOR=1 60 PLOT X,Y 70 GOTO 10 This worked fine going up and left, but not when going down and right. When I moved the joystick all the way down, the plot point turned into an exclamation mark. When I moved it all the way right, the computer beeped and said ILLEGAL QUANTITY ERROR IN 60. I have some vague ideas of what caused this, but my instinct was to fix it this way: Ran it that way. Holy moly, it worked! Thus the full code for my little experiment: 10 X=PDL(0) : Y=PDL(1) 20 X=X/6.4 : X=X+0.5 30 Y=Y/6.4 : Y=Y+0.5 40 PRINT INT(X), PRINT INT(Y) 50 GR:COLOR=1 60 IF X>39 THEN X=39 70 IF Y>39 THEN Y=39 80 PLOT X,Y 90 GOTO 10 Now I can move a plot point around the screen by using the joystick and without having to redraw a black point over the previous point each time. Then I had an epiphany... drum roll please... I ACCIDENTALLY JUST PROGRAMMED MY FIRST SPRITE! Cool. As I posted a few weeks ago when making the Lego robot code work, you guys can tease me if you like :) but this is a milestone. I stumbled onto how to code a sprite in BASIC. Granted, it's only lo-res graphics, but I would think the same exact method should work in hi-res graphics mode. Also some things aren't perfect -- when I run the program without touching the centered joystick, it reports a plot position of 18,23 -- so I'll experiment with the physical trim knobs. Low-quality video (to accompany lo-res graphics...) is here: http://www.snarc.net/EK_first_sprite.mp4 (It plays fine in VLC but appeared too tall in the default Linux Mint player.) _______________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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K-Fest carpool?
by Evan Koblentz 03 Mar '17

03 Mar '17

I've always wanted to go to K-Fest. I may apply for one of their "golden tickets" this year, however that still involves getting one's self to Kansas City. Is anyone interested in getting together with a few people for a carpool? Obviously not in my tiny car :) but I'd be happy to split the driving and gas $$. Paying for a flight or the cost of all that gas by myself would be beyond my means right now. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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Re: [vcf-midatlantic] Live auctions at VCF-East?
by VAXman＠tmesis.org 03 Mar '17

03 Mar '17

Evan Koblentz via vcf-midatlantic writes: >We can't have auctions. Requires a state gaming license and a >professiona= l auctioneer. ... and this could happen: https://www.youtube.com/watch?v=_Da2JjSEQ2Q

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Front gate worker(s) @ VCF East
by Evan Koblentz 02 Mar '17

02 Mar '17

Everyone, We need front gate workers during Saturday/Sunday (not Friday) during VCF East. It's a hard job. The person needs to be firm at times, in order to tell people "no" who are used to doing whatever they want at Infoage. The person also has to show for their scheduled hours no matter what, even if it's pouring, freezing, armageddon, whatever... We are willing to pay (modestly) for the right person(s) to do this job. Must be at least 16: this isn't a job for children, nor for people who aren't comfortable being on their feet/outdoors for long periods of times, nor for the timid. Contact me off-list if you know someone who is interested. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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Another DC-area rescue
by Evan Koblentz 02 Mar '17

02 Mar '17

We need a Cromemco Z2 picked up in Silver Spring, Maryland (the homeowner is moving in May) and delivered to the museum (no hurry). ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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VCF East lodging
by Evan Koblentz 01 Mar '17

01 Mar '17

Several people asked Jeff B. and I about staying at InfoAge during VCF East. There are a certain number of beds available. To keep it fair, I sent an email tonight to exhibitors, speakers, and official show volunteers. If you are an exhibitor, speaker, or official show volunteer, and you did NOT get that email, then it's an oversight by me. Send me a private message to evan(a)vcfed.org. We are not allowed to offer lodging to people simply attending the show. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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VCF East flyer
by Evan Koblentz 01 Mar '17

01 Mar '17

A few people asked for the event flyer. Here's a link: http://www.vcfed.org/evan/eastxii.pdf .... download and share widely! ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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VCF East exhibit reg is closed
by Evan Koblentz 28 Feb '17

28 Feb '17

Here's the final exhibitor list: http://vcfed.org/wp/festivals/vintage-computer-festival-east/vcf-east-exhib… Anyone wishing to register an exhibit now must grovel at my feet. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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Ad space in VCF East program booklet
by Evan Koblentz 28 Feb '17

28 Feb '17

Anyone want to advertise their business in the VCF East program booklet, or know someone else who does? Cost is $400 for a full page, $200 half, and $100 quarter. Your ad will reach a few hundred tech-minded people, most of whom live with a couple of hours of here. The pages will be 5.5" wide x 8.5" tall (8.5x11 sideways folded in half). We print in color. Deadline is Friday, March 10 at midnight. Email me privately (evan(a)vcfed.org) if you're interested. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)3 educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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