playboy@altger.UUCP (09/24/87)
I have now a Hayes modem which can run 12 baud. Now I have a big qustion: when I try to run 1200 baud I recieve garbage. Only when the host sends slowly (e.g. while chatting with the sysop) the characters that I recive are readable. Is the C-64 too slow to recieve with 1200? know people in the USA who use the C-64 with 1200 without any probs. Is there a solution? Please answer. uucp: ...!seismo!mcvax!unido!altger!playboy smail: playboy, p.o.box 188, 4125 riehen, switzero: wa
rjray@uokmax.UUCP (Randy J Ray) (09/28/87)
In article <9500004@altger.UUCP> playboy@altger.UUCP writes: >I have now a Hayes modem which can run 12 baud. Now I have a big >qustion: when I try to run 1200 baud I recieve garbage. Only when >the host sends slowly (e.g. while chatting with the sysop) the characters >that I recive are readable. Is the C-64 too slow to recieve with 1200? > know people in the USA who use the C-64 with 1200 without any probs. >Is there a solution? For some reason (that I have yet to REALLY understand, simp that I am), CBM machines cannot run true 1200 baud, due to some clock/cycling conflict. Most terminal programs and BBS programs (including C-Net) take the number obtained after dividing the constant given in the '64 ref manual and multiply it by about 0.966 I believe. I.e., given the constant RC (different for you than me, being in Europe), do RC/bd and * by 0.966. There are a number of operations you have to do in a similiar way, as well. I shall try to find my copy of the C-Net baud change prg file. Yes, as you guessed, you need to open your modem file with user-selected baud rate (low nibble of the 1st register is 0). Randy rjray@uokmax.UUCP&
tomb@hplsla.HP.COM (Tom Bruhns) (10/09/87)
I have some information on this buried somewhere. I used to use my c-64 quite successfully at 1200 baud, and at 2400 with some coaxing, using any of several terminal emulator programs I got from a local bbs. (Used to, only because I've become Amiga-ized lately) The problem has to do with the software in rom which does the serial-to-parallel conversion. As I recall, it sets some bit times that don't account for quite all the time that the instructions take (total time = hardware timer plus some instruction overhead). This is a non-problem at slower speeds, but causes screw-ups at high speeds. Try to follow up with a local (to you) bbs; they should know. Else, you can e-mail me and I'll try to look up the details for you -- but I don't read this group all that often now. Cheers, Tom Bruhns hplabs!hplsla!tomb
sl131084@silver.bacs.indiana.edu (10/27/87)
Recently I was playing with some of the new GEOS software for the C=64, and lo and behold I found that the program GeoLaser uses a 9600 baud speed! After talking to a good friend of mine about it, and confering with another friend with connections at BSW (the published of GEOS), we have figured out that the programmer of the geoLaser program needed a way to send data to an Apple LaserWrite (POstScript) at 9600 baud. Solution? Seeing as how the C=64 (and 128) don't contain UART chips, and do all of the RS232 type operations via software, he just wrote his own rs232 driver program. It blanks the screen, but it works... Might try to extract it at sometime... If I can I'll post something else here 'bout it... -El Gato