rex@otto.COM (Rex Jolliff) (07/18/87)
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I was thinking of buying a coco (2 or 3) and I was wondering if the rs-232 port
is all hardware or if any of it is implemented in software. Let me clarify
this. I own a Commodore-64, and it's rs-232 port is set up as follows: an
8-bit parellel port is used, and each of the rs-232 pins, including the TxD and
RxD, are driven by a line coming off the parellel port. A piece of software is
tied to the NMI vector and the timer is loaded with a value that comes as close
as they could to the actual baud rate. This doesn't really work at all past
1200 baud, and not even that good at 1200 baud. I would rather not buy another
computer with a kludge like this, and if coco's have a HARDWARE UART, I would
like to know. This probably is'nt in everybodies interest, so E-mail replies.
Rex.
--
Rex Jolliff (rex@otto.UUCP, {akgua,ihnp4,mirror,sdcrdcf}!otto!rex)
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What happened to our superior space program?pete@wlbr.UUCP (Pete Lyall) (07/20/87)
In article <500@otto.COM> rex@otto.UUCP (Rex Jolliff) writes: > >I was thinking of buying a coco (2 or 3) and I was wondering if the rs-232 port >is all hardware or if any of it is implemented in software. Let me clarify >this. I own a Commodore-64, and it's rs-232 port is set up as follows: an >8-bit parellel port is used, and each of the rs-232 pins, including the TxD and >RxD, are driven by a line coming off the parellel port. The original coco, coco2, and the new coco3 come with this sort of affair as standard. You can buy the RS-232 pak as an add-on (you'll either need a multi-pak, or a Y-cable) for around $30 if you hunt. The Rs-232 pak uses a 6551 UART, and is fully implemented in hardware. If you get the proper software, you can drive it at 19.2Kbps no problem. -- Pete Lyall Usenet: {trwrb, scgvaxd, ihnp4, voder, vortex}!wlbr!pete Compuserve: 76703,4230 (OS9 Forum Sysop) OS9 (home): (805)-985-0632 (24hr./1200 baud) Phone: (818)-706-5693 (work 9-5 PST) EATON Corp, IMSD, 31717 La Tienda Dr., Westlake Village, Ca. 91359 ----------------------------------------------------------------------
jonh@tekgen.TEK.COM (Jon Howell) (07/21/87)
The CoCo's built in port was designed mainly for outputting. (printer) The software has to generate all the timing by itself. It can output to 9600 baud (or 19.2 in 2x speed), but input is not worth anything over 300. (In our mag- azine, The Rainbow, someone claims to have gotten reliable 4800 baud operation, but this really eats processor time.) The advantage to the CoCo is that for $30 you can get a hardware UART (19.2, and for $1.10 and some soldering, 38.4) and keep your printer output. Goofy that they didn't just put it in the CoCo, but then less percentage of CoCo people use their CoCo for communications as do Commodore owners. (That's why you see more commodore BBSs, [not to mention that more commodores exist!] and such) CoCo people go more toward OS9 or grafix, as far as I've seen. To help simplify your search for the right new computer, let me tell you what a CoCo setup would cost. 32 Col's 51/85 (85 is illegible) Col's 40/80 Col's (80 w/ monitor) CoCo2 $69 CoCo2 $69 CoCo3 $169 (mail) UARTpak $30 UARTpak $30 UART pak $30 Disk system $169 (mail) Disk system $169 (mail) Y-pak $30 (mail) Y-pak $30 (mail) ------------ ------------------- ------------------------ Total $99 Total $298 Total $398 Some notes: The Disk system on a CoCo does not go through the serial port as on a Commodore--it is hooked directly to the bus. (The "expansion" port) The UART also uses the same port, that is why you need a y-pak. If you want the CoCo solely as a terminal, ideas 1 & 2 are good. (You can use any serial printer with CoCo, just a matter of cables. There are ser=>par conv also) If you want to use a CoCo as your main machine, then a CoCo3 wins easily. A CoCo3 Os9 Level 2 system would look like this: CoCo3 $169 UART $30 Disk 0 (1st disk)$169 Multipak $69 (Tandy's y-pak--4 branches instead of two--need for os9) OS9 Level II $63 (mail) 512K RAM expan. $80 (mail) --------------------- Total $580. This is a very good system. If you are not familiar with os9, it is unix-like operating system for the 6809/68000. Level 2 has windows, graphics drivers... Languages available include C, BASIC09, Pascal, others. Deskmate 3 (for level2) is good Radio Shack software, and by far the best is the (coming soon) Multi-Vue package. It emulates the Mac user interface...VERY impressive, I hear. (Mouse- oriented, ya know?) But by far the most promising is the Sculptor package from FHL (Frank Hogg Laboratories). I am not sure about the details, but Sculptor is a 4th generation program-generating program that (understand that? :-) lets you write your own business database software QUICKLY. I heard that someone at FHL spent 2 minutes writing a program that can find a name out of a list of 20,000 in less than 2 seconds! Enough witnessing for my favorite machine (:-), but I wish you well on your search for the perfect computer... (Which is one name I wouldn't give a C64, but then perfect is a big word. :-) Good luck, Jon p.s.-sorry I couldn't mail this...somebody choked on the machine "io". --Jon -- ___ __ , __ __ _ , , __ , , ___ __ | |_ | |_ / / \ |\ /| |_\ | | | |_ | -- It's good for your | |_ |_ |_ \__ \_/ | V | | \_/ | |_ * health!