2024-03-02: The wiki ran out of disk space, so things were not working. This has been resolved by adding another 5GB of quota ;-) Thanks to Tim Lindner for reporting the issues. 2020-05-17: If a page gives you an error about some revision not being found, just EDIT the page and the old page should appear in the editor. If it does, just SAVE that and the page should be restored. OS-9 Al (talk) 12:22, 17 May 2020 (CDT)

Undercolor/850106/Box 6809

From CoCopedia - The Tandy/Radio Shack Color Computer Wiki
Jump to navigation Jump to search

Home Articles Companies Publications Hardware People Software Timeline ... Emulators Internet Resources
(Don't see something listed? Click "edit" and add it! Together we can build this database. When making a new info page, refer to this InfoBox Template for guidelines.)

UnderColor, Volume 1, Number 6, March 8, 1985

  • Title: Box 6809
  • Author: empty
  • Synopsis: Thoughts and ideas from you to us.
  • Page Scans: Link



*Just got 1st issue of Under Color . . . some very interesting stuff. I don’t know who you use as a communications consultant, but he has some gaps in his knowledge. Maybe I can help a little in this instance, but of course Wayne Day is probably your best bet for most stuff. What I’m getting at is the letter from Samuel Murphy. (DEFUSR, issue 1). He asks if the "radial-Vac" (sic) modem (Model VA2450) can be used with the Color Computer.

Actually, he is talking about "Racal-Vadic," the first company to come out with a 1200 baud full duplex dial-up modem (it was just Vadic back then). The Vadic 2450 uses a different modulation scheme than the now more-common Bell 212 1200 baud modem. Unlike the 212, which can also operate at 300 baud, the Vadic modem only operates at 1200 baud. So, to use it with the CoCo, first of all you must be sure you have a terminal program that will run at 1200 baud. For reliable operation, this means using a hardware UART, such as the Tandy RS-232 pak. Secondly, you have to find out if the service/BBS that you want to call uses Vadic modems. If not, you're out of luck. It is very unlikely that any free BBS uses Vadic modems. CompuServe, and to a greater extent, Tymnet, have some Vadic ports. They are specifically noted in our access number list as "1200 Vadic." As for cables, l believe the 2450 takes a standard 25-pin connector.

I'd suggest he not attempt to use the Vadic modem for BBS access, and instead buy a low-cost 300 baud modem for this purpose. There are rumors that a number of companies soon will be selling modems under $50.—Sandy Trevor

  • I have been playing around with speech. I have three versions of it going. One uses the SC-01, two use the SPO256-117 IC (clock) and the third uses the SPO256-AL2 (allophones). The real big difference is the I/O, as I am using the serial port for all three.

At the present, I have about twenty pages of "how to build it and use it" written for the SC-01 and would I be able to put at least that much together for the two SPO256 packages.

Please find enclosed a short listing that I use to check out the SPO256 packages. This may give you a little better idea of what my serial speech is all about.

That reminds me, can and would you modify the remote keyboard program as was in the Rainbow (Nov. ’83) issue so that what is received is not sent back out? This would enable me to use the S600 typewriter as a real keyboard and allow the composition of programs away from the CoCo.

One way of getting a good (real ACIA) serial port is with the RS Deluxe RS-232 Program Pak #26-2226. Of course you have to have the Multi-Pak Interface to have it with disk and etc. The rub comes in that the pak was intended for tape use and there doesn’t seem to be any patches to put it on line with the disk as they both use &HC000. Sure would be nice to use the remote keyboard through this ACIA port. (hint, hint)

In your future articles if you use any Disk ROM routines please include the addresses for the 1.1 version. Some of the programs as featured in other magazines don't tell which version was used but I've come to assume 1.0!—MichaeI J. Lill

*I keyed in Dennis' interrupt driven real time clock program (Issue 1). It’s nice but I had to make some changes. Since l have Disk Basic, my interrupt vector was not the same as that in the article. I added the following lines to pick up the existing vector and plant it after a JMP at the end of the routine:






The label Jump looks like this:


I also had to remove the line that read from the PIA port and cleared the interrupt flag. I guess the Disk Basic checks it later because it prevented the normal IRQ routine from turning off the disk drive.

The routine has a drawback when used with disk. The disk routine masks the interrupts for much more than one tick. Any disk I/O therefore slows down the clock. OS-9 has the same problem. The thing to do would be to modify the disk routine to bump up the clock count after every sector read or write in order to compensate for the slowdown.—Joseph M. Miller


*l also have an MC-10 and would enjoy articles on them, especially memory expansion past 8K. Radio Shack did it with their memory module. They must have disabled the LS155 on the board and used another chip for device selection.

I know Dennis is a music person: ever thought about software for the RS Voice Pak?—Joseph M.


*l pick up a Computer Shopper, now and then, and find pages and pages of ads on disk drives. They list them by number or if they work on a PC. They almost ignore "Radio Shack People." I know it if works on any TRS-80, it should work on the CoCo.

I think that many RS stores imply that you must use CoCo drives with the CoCo, even the right color. So, how do I tell if an advertised drive will work with my CoCo? "Ain’t no bargain if it don’t work . .

How about a home brew modem'? l don’t have enough interest to pay $100-$200 for one. A friend suggested using the PC board out of a $10 telephone, a XFI2206 and a few OP-AMPS & etc., and be on line for $25 or so. Could be hand-wired on a perf-board. They can’t put you in jail if you don’t sell them, can they? The telephone PC board would by "type approved . . ."—Bill Frame


*I received the 64K upgrade and the Memory program and everything worked out very well. That 37 hours test is a long one to sit back and wait for. Come to think about it, I should be telling this to the "Old man on the Green Mountain." Please pass this along to Dennis and Company.

I have read Dennis' material in 80-Micro and in Color Computer and appreciate his writings. Naturally, Bill Barden and Terry Kepner are also a welcome sight...—V.K. Hatfield

*Heighdy! Glad to see everyone survived the crash of the Hindenburg. Fie to the feudal lords Ziff and Davis, a pox on both their houses (They bought an article and ate it when CCM folded — now I'll never see print.). — Fred Toon

*I am extremely interested in information on new models and revisions of the Color Computer and possible enhancements like expanded memory and graphics, such as the Motorola SAM chip set. That new SAM chip and the 16Kx4 memories is particularly intriguing; wish there was more information. I think it would make a good series of articles to cover each model of the Color Computer, to explore and compare the differences. Your coverage of the differences in this first issue was very helpful and interesting and I hope you’ll keep up this practice in the future.

My system looks like this: I started with a used 4K CoCo about two years ago. It now has a homebrew video output and Zenith green screen monitor, 64K plus the DSL 128K mod (just installed), two 40 track DSDD drives and one 80 track DSDD, an Okidata 92 printer, a Multipak, and a WorkPack ll. Not bad for a "game" computer!

Disk operating systems are ADOS and OS-9, the latter with D.P. Johnson's SDISK. l just got Basic09 this week and am very excited with it—this from someone who hates programming! I bought the C compiler a long time ago but have never been able to figure out how to program in C; it makes little sense to me but I intend to try again since that’s the operating system we’re going over to where I work. Again, I hope you’ll provide lots of coverage for OS-9 and the available languages.

My main use of the system at present is as a word processor. As such, it has been such a valuable aid that I consider it worth all the money spent on hardware improvements to date and will likely always spend more time writing correspondence and fiction than actual programming. Can’t emphasize this enough.

Telewriter 64 is my favorite program; Dynastar is cumbersome and clunky by comparison, although the Wordpack ll is going to make it much more useable. The main problem with Dynastar was that l was limited to a one-way-only window of 15K of text, couldn’t page backward through a disk file, which is a fatal flaw for my needs. By freeing up the memory space used for O-Pak and deleting unnecessary OS-9 modules like PIPES and RS-232 I now have as much as 143 pages of contiguous free

memory and about 26K or so of text buffer. This is not enough, but it is a major improvement. I need more text buffer! Do wish Telewriter could be put on OS-9 and use WordPack, as it stands it is a very easy-to-use and powerful word processing program for creative writing — especially for those on a limited budget!

Hopefully the do-it-yourself move to 128K (and more) will spur software development to complement it, just as the move to 64K did. More articles and coverage on this important development, please?

Dream Dept: how about an upgraded Color Computer that’s a real improvement? The idea is to keep the powerful 6809 up and software that’s already been developed for it. Going to a 68008 might be desirable since it already has the extended addressing range, but since it is not code-compatible one has to almost start over with the software. At the risk of sentimentality, I'd like to keep the good ol' 6809.

My wish list goes like this: a fully decoded

keyboard with all the keys we need, serial and parallel hardware I/O, let's not give the CPU any more overhead than we have to. Disk controller already on the board as a standard feature (What’s the point of a CoCo for OS-9 or Flex if it doesn't have a built-in disk controller?). Leave the joysticks out, add them and/or a mouse as optional items where

they’d be needed. I'm not opposed to games, it’s just not a major need on my computer. Ditto for a cassette interface.

We never have enough memory: let’s start with at least 128K expandable to 1000K and an extended addressing range preferably via a 6829 MMU or some other hardware memory controller, optionally some kind of bank-switched arrangement. I think some sort of piggy-back board arrangement for the additional memory might be better than trying to cram it all onto the main board. I don't know whether to go with 64K chips or bite the cost bullet and go

256K chips. Too early for the 1M chips . . .

Improved graphics display with its own memory such as the Motorola RMS set—one thing I do like about the Macintosh is its graphics. Internal expansion slots for nice things like hard disk controllers, modems, and additional I/O. Better interrupt handling and DMA for faster hard disk transfers. All of this built into a Model 4-like enclosure, or with exterior video monitor.

What do we get? Probably something expensive, but it’d be one heck of a single-board microcomputer .... I’ve a feeling though that the 6809 simply isn't going to carve out the niche it deserves and that the 68000 family ought to be regarded as the proper and desirable successor. After all, OS-9 has been implemented for it, so there is at least some familiar software support.—Damon Hill

*Was just about to write and ask where the new mag was when it arrived in the mail . . . looks good. I hope that you leave the games to Rainbow and Hot CoCo. Dennis was the best thing in the C C Mag. Lost a year on a renewal but don’t think Ahl’s rag is worth the postage. My preference is utilities, hardware and Q & A spots like Kepner’s. The Color Computer News was great . . . some were better than

Rainbow . . . still get them out on a rainy day and find something new.

For the record, I have a 64K E, (my up-date), CTR-8OA, Oki 82A, 2 TEAC drives and Bill Vergona’s Cer-Comp DOS and "bare board" PJC six-slot expansion port. On the shelf is a 16K D Basic and a spare F? board. Transformer hole is in a different spot . . . plan to move the transformer and junk the D board. . . some day. . .

The Cer-Comp DOS works fine. It is much better than the RS . . . but . . . I do not have enough smarts to convert many of the programs that I would like to use. Just ordered the HDS bare board for Xmas . . .—Bill Frame


*What is the real reason for using a printer in your magazine that has 0 and O as the same character?

Other magazines have this same problem!—

William H. Link

William—the real reason is that, so far, no line printer font is available that includes every character and spacing any computer magazine needs. Choosing a font that doesn't differentiate between a slashed-zero and the letter O saves us from some other, more confusing, problem.—D.M.

From the Editor:

• OK, calm down. We missed it—Figure 4 from Dennis' Part I of the real-time talking clock was, indeed, missing from issue 1. Just proves I’m not quite perfect .... Anyway, the figure will be found floating somewhere (and duly identified) in issue 5.

• Those of you who have been struggling with Dennis' memory tester from the last issue of TCCM: The final test takes about 37 (not a misprint) hours

to run. That’s why you don’t get results if you're impatient. Just let it run . . .

• Several folks have asked if their subscriptions to UC can start with issue 1. We will start all subscriptions with #1 until the printed copies of #1 run out. After that, subs will start with the earliest available copy, giving as many folks as possible as complete a set of the mag as possible. Incidentally, there’s only about 500 more of issue 1, so tell those Iaggard friends of yours to hustle . . .

• Those of you missing items from TCCM days—I’Il be happy to make copies of any articles in any TCCM I still have copies of, if you'll send money for copying and postage. Be as accurate as you can with what you want and when it appeared: memory fades as time passes . . .

• Finally, rumor has it that if you persist long enough, refunds will be received from Ziff-Davis: Persevere!


*OCOCO is the other CoCo club of Atlanta, GA. Meetings are every fourth Tuesday in each month at the DeKalb Community College Central Campus in Clarkton, GA. Dues are $10 a year; meetings begin at 7 PM.

For more information call (404) 396-5395 or CHIPS Inc. at (404) 457-2447, or write to David Fresch, 4923

Mill Brook Dr., Dunwoody, GA 30338.

From Manufacturers:

*Bob Rosen of Spectrum Projects offers the following POKEs to modify the "problem" ROMpaks "Downland" and "Stellar Lifeline." He notes that the programs are to be used with Spectrum’s "Multi-pak Crak," 64K disk and RS Multipak required.