Thanks to today’s CoCoTALK!, I learned that the Roar CoCo/Dragon emulator now has a web browser version:
https://www.6809.org.uk/xroar/online
It joins the JS Mocha emulator:
http://www.haplessgenius.com/mocha/
Fantastic!
Over in the CoCo Facebook group, Diego Barzio just posted a note about discovering some BASIC program line comments that had left out the REM keyword at the start. Because those lines were never the target of a GOTO, there was no error. This had the side effect of saving a byte (or two, since most do “REM ” at the start) for comment lines.
This made me think about what was going on. BASIC will allow you to type in anything, and will try to parse it (to tokenize the line) and produce an error (?SN ERROR, etc.) if there is a problem. But, when you are typing in a line, this BASIC doesn’t check anything until that line is actually ran in the program. (Other versions of BASIC will check when you hit enter. Didn’t the Apple 2 do that?)
In an earlier article, I mentioned that “REM” tokenized into one byte, and the apostrophe (‘) turned into two bytes because it was “:REM(space)” allowing you do do something like this:
10 REM This is a comment. 20 'This is a comment
Since most folks type “REM(space)”, using the apostrophe without a space after it takes the same room. But if you include the space:
10 REM This is a comment 20 ' This is a comment
…that would make line 10 take one byte less (REM + space is two bytes, versus ‘ + space which is three bytes).
Now, if you do not include REM or apostrophe, you can save a byte or two for each comment. If you program has 50 lines of comments, that’s 50-100 bytes.
However, this made me realize that leaving out the REM would cause it to try to tokenize the line, and turn any BASIC keyword into a token, saving even more memory. If your comment included words like PRINT, OR, ELSE, etc., you’d save even more room!
As you can see, because this comment uses the word PRINT (five characters), the version without the REM appears to save six bytes — it saves the apostrophe (two bytes, or would save “REM(space)” for two bytes) plus tokenizes the PRINT keyword down from five bytes to one (saving four more bytes).
Interesting BASIC interpreter abuse, isn’t it? As long as you never run this line, you might save memory by leaving our REM (depending on if you use any keywords). I could imaging comments saying “SHOW THE USER NAME” changed to “PRINT THE USR NAME” to tokenize two words (PRINT and USR).
You would still need REM at the start of the code for any initial comments, and during the code, but for subroutines you could do this:
10 REM THIS IS MY PROGRAM 20 A$="HELLO, WORLD!":GOSUB 1010 999 END 1000 PRINT THE MESSAGE 1010 PRINT A$:RETURN
The GOSUB jumps to 1010 and can find it, and since the program would END before reaching 1000, that would work.
With great power comes great responsibility. Use this wisely :) and thanks, Diego, for noticing this.
Until next time…
One of the all-time best ports of Donkey Kong on a 1980s home computer was a clone called Donkey King (later renamed to The King). Although we didn’t know this until years later, it was authored by Chris Latham, who also created the first CoCo game to require 64K – The Sailor Man (a clone of Popeye).
Last week, the gang over at CoCoTalk (the weekly video chat/interview show) started a game contest where everyone is invited to try to set a high score on some CoCo game. The first game chosen was Donkey King, which is quite fitting since it’s one of the greatest CoCo games ever. Unlike most (all?) other versions of the day, it features all four levels as well as the intermissions (see the Donkey King link above for screen shots). It also plays amazing well and is as frustratingly difficult as the arcade game it was based on.
For those interested in trying it out, you can go to the JS Mocha CoCo Emulator webpage (the Java Script version of Mocha, which was original a Java CoCo emulator). It is one of the games available there.
You will find it in the second column. Just select it then click Load Bin. It uses the right joystick, I believe, so you can select “Dual Key R” from the Joystick config and that will map that to the keyboard – Arrow Keys and Space Bar (to jump).
If you want to hear the sound effects, you have to checkbox the “Sound” option in the lower right of this screen.
Give it a try and see what you think.
Until next time…
John Linville recently announced a CoCoFEST! Challenge on the CoCo Crew Podcast Facebook page. The idea is to start and complete a new CoCo project between February 15, 2020 and April 1, 2020 (day after Valentine’s Day through April Fools Day). The project doesn’t even have to be technical (he uses the example of designing a dust cover for a Multi-Pak).
I’ve been thinking about this since I have dozens of past experiments that could easily turn into new projects. But I also thought it might be an excuse to start “yet another” experiment specifically for this challenge.
Recently I took possession of a HuskyLens from DFRobot. It is an AI camera device that started out as a Kickstarter project last year. The tiny gadget includes a camera, touch screen, and AI software that can do things like:
I acquired a HuskyLens specifically for Halloween projects, but since it communicates to a host computer over serial, it could be interfaced to a CoCo using a cheap TTL-to-RS232 adapter like my CoCoWiFi and SirSound projects use.
Since the slowest speed the HuskyLens firmware communicates with is 9600 baud, I’d have to do this using an RS-232 Pak under NitrOS-9 (so I could easily do it in BASIC09 or C), else I’d have to resort to assembly language under RS-DOS. If I go the assembly route, I’d have to see what code I could find to handle 9600 baud via bitbanger, else the RS-232 Pak would still be required.
Bitbanger is quite out of my wellhouse, since the only bitbanger code I’ve ever worked with was a remote terminal driver published in Rainbow that I modified to add features to. The RS-232 Pak I could probably handle since my first commercial program was a MIDI Librarian for a CoCo MIDI Pak and I wrote code for a much faster baud rate (31,500).
It wouldn’t be pretty, but I think I could make it work.
The question is … what does one do with an AI camera hooked to the CoCo? Perhaps…
What can you think of? Ideas are appreciated…
This one even uses my customized version of Bo Zimmerman’s Zimodem ESP8266 Firmware.
https://www.simulant.uk/shop/retro-vintage-computer-wifi-modem-rs232-serial-hayes-compatible
Thanks to Rob Inman for sharing this link over on Discord. They have an RS-232 to WiFi module available, based on the ESP8266 module. They chose to include my pre-configured fork of Bo Zimmerman’s ZiModem (with the settings for standard RS232 rather than Commodore serial). Cool.
https://www.simulant.uk/shop/retro-vintage-computer-wifi-modem-rs232-serial-hayes-compatible
As mentioned elsewhere, there are some CoCo-related extensions available for the Microsoft Visual Studio Code editor. I did not realize that MS released this editor for Mac and Linux as well as Windows.
Here is the free editor:
Once installed, you can download (from within the editor) extensions.
Here are two extensions by Tandy UK — one for COLOUR BASIC and the other for 6309/6809 assembly:
https://marketplace.visualstudio.com/publishers/Tandy
There is another 6809 assembly extension available:
https://marketplace.visualstudio.com/items…
It colorizes files ending in .a or .asm.
I don’t see many details about the Tandy UK ones, but I am indeed getting colorized BASIC keywords when I have a .bas file.
In the 1980s and 1990s, there were many computers made that used a 15Khz analog RGB signal. These included the CoCo 3, Commodore Amiga, Atari ST, etc. There were a number of monitors to choose from to use on the CoCo 3, with one of the most popular being the Magnovox (remember them?) 8CM515. It supported RGB-A but also had composite audio/video so you could get the old CoCo 1/2 artifact colors when needed.
I thought the days of 15Khz was long gone. We have had a few solutions for hooking up a monitor to the CoCo 3, including an FPGA project, Cloud-9’s VGA converter, and the Switch-a-roo cable with a SCART converter box.
But Alexandre Souza on Facebook let me know they use all kinds of LCD monitors in Brazil, and pointed me to this list of modern monitors that still support 15Khz analog RGB:
http://15khz.wikidot.com/?fbclid=IwAR3S-JRwwEau0WsJsRTBXaNrgXIX92pYfdGPvt0D-CJpYPGnat2nD4A3h4k
One of the highly recommended monitors on the list is on Amazon for $139. It might take just as a cable to make it work with the CoCo, or possibly a bit of signal inversion (just like the old days).
Anyone know more on this?
I have three Ken-Ton auctions going now:
I may also be selling my SuperIDE interface, though I am currently using it just as a realtime clock. I need to find another clock solution before I let that one go.
Updates:
TLDNR: See the video at the end.
In 2015, Sub-Etha Software rocked the retro world with the announcement of CoCoPilot. (And by “announced” I mean “posted a blog article about how to install DriveWire on a Raspberry Pi. And by “rocked” I mean “posted a block article about how to install DriveWire on a Raspberry Pi.)
In 2017, Sub-Etha Software raised the bar again by announcing SirSound, the serial port multi-voice sound “card” for the CoCo. (And by “raised the bar” I mean “posted another blog article”.)
In early 2018, Sub-Etha Software released details on CoCoWiFi, and showed you how to build your own for under $10 instead of waiting for Sub-Etha Software to actually manufacture them. (And by “released details” I mean “posted yet another blog article”.)
In late 2018, Sub-Etha Software shocked the CoCo Community with the proposal to end all proposals: PreciousPak. (And by “shocked” I mean “posted a block article about something I think would be really cool but don’t have the hardware skills necessary to make happen so I hope someone else will do the work for me, please and thank you”.)
And now, in 2019, Sub-Etha Software is proud to announce…
CoCoPilot DELUXE is the result of dozens of man-minutes of thought on the subject of “what should I do with all the Raspberry Pi stuff I have on my desk?”
Much like how PreciousPak solves all our problems when it came to CoCo cartridge add-ons, CoCoPilot DELUXE strives to solve all our problems when it comes to CoCo bitbanger serial port add-ons. (And by “solves all our problems” I mean “wouldn’t this be fun to play with?”)
With CoCoPilot DELUXE plugged in to your CoCo’s built-in Serial I/O port, you will have:
In this list, there are a few “new” things we can’t currently do. Printing from CoCoMAX 3, Tandy Home Publisher or any other graphical print software is not currently possible (is it?). A new layer would be written to interpret common printer “driver” codes (Tandy, IBM, Epson, etc.) — including color — and render the incoming data to an image that represents all the dots the printer would have printed. (Heck, we could even emulate the old plotter printer thing.)
SirSound could work the same as the hardware SirSound (API compatibility), but could be expanded to do more voices, and use better sounds. The Pi has simple libraries that can product multi-voice music.
WiFi Modem would be similar to the CoCoWiFi (Zimodem) project, but the “AT” Hayes Smartmodem commands would be different since we’d just use one of the many “serial to network” programs/scripts readily available.
All we need is a bunch of software, an RS-232 interface for the Pi, and some switches to select which mode you want the CoCoPilot DELUXE to be in.
Spiffy.