Sirald@cup.portal.com (Andrew Lionel Dalrymple) (05/31/89)
____________________________________________________________ Hello, Would any h/w tech-types know WHAT it is in the LASER 128 that I need to tweek to speed up the repeat key? It goes much too slow for doing things like the underline boarders you see above and below my message. Cordially, A. DALRYMPLE sirald@cup.portal.com sun!portal!cup.portal.com!sirald ____________________________________________________________
farrier@Apple.COM (Cary Farrier) (06/01/89)
In article <18970@cup.portal.com> Sirald@cup.portal.com (Andrew Lionel Dalrymple) writes: >____________________________________________________________ > >Hello, > > Would any h/w tech-types know WHAT it is in the LASER >128 that I need to tweek to speed up the repeat key? It goes >much too slow for doing things like the underline boarders >you see above and below my message. > > >Cordially, > > A. DALRYMPLE sirald@cup.portal.com > sun!portal!cup.portal.com!sirald >____________________________________________________________ Well, lets see. If *I* had a Laser 128, and I wanted to improve on it, I would probably jump all the resistors (no resistance, then it should run faster, right?) :-) :-) :-) :-) Cary Farrier
jac@paul.rutgers.edu (J. A. Chandross) (06/02/89)
Sirald@cup.portal.com (Andrew Lionel Dalrymple) > Would any h/w tech-types know WHAT it is in the LASER > 128 that I need to tweek to speed up the repeat key? Having never seen the inside of a Laser, I can only speculate how they generate the repeat. It is common practice to use a 555 timer chip to generate pulses to a keyboard encoder repeat frequency input. The frequency to this chip is controlled by a resistor-capacitor pair. If you look at a 555 data sheet you'll find the appropriate values for all sorts of time constants. Just pick the rate you want and replace the resistor of the RC pair. I've done this on an Apple ][+ a great many years ago, and it worked very nicely. Needless to say, this probably voids your warranty, and I won't buy you a new Laser if you butcher it. Jonathan A. Chandross Internet: jac@paul.rutgers.edu UUCP: rutgers!paul.rutgers.edu!jac
jdm@h.cs.wvu.wvnet.edu (James D Mooney,205K,7,2913548) (06/06/89)
From article <18970@cup.portal.com>, by Sirald@cup.portal.com (Andrew Lionel Dalrymple): > ____________________________________________________________ > > Hello, > > Would any h/w tech-types know WHAT it is in the LASER > 128 that I need to tweek to speed up the repeat key? It goes > much too slow for doing things like the underline boarders > you see above and below my message. > According to the Laser 128 Technical Reference Manual, autorepeat at a *fixed* rate is provided by the keyboard encoder. The keyboard encoder for the 128 (and 128/EX) is an 8048 chip, which is a simplified 8080 with 1K ROM (not PROM) on chip. Most likely the speed is encoded in the ROM and cannot be changed unless you can produce an 8048 with a modified program. It is a general purpose CPU; there is no place for an external timing input. Jim Mooney Dept. of Stat. & Computer Science (304) 293-3607 West Virginia University Morgantown, WV 26506 INTERNET: jdm@a.cs.wvu.wvnet.edu
jac@paul.rutgers.edu (J. A. Chandross) (06/07/89)
jdm@h.cs.wvu.wvnet.edu (James D Mooney,205K,7,2913548) > According to the Laser 128 Technical Reference Manual, autorepeat > at a *fixed* rate is provided by the keyboard encoder. The > keyboard encoder for the 128 (and 128/EX) is an 8048 chip, > which is a simplified 8080 with 1K ROM (not PROM) on chip. > Most likely the speed is encoded in the ROM and cannot be changed > unless you can produce an 8048 with a modified program. It is > a general purpose CPU; there is no place for an external > timing input. I expect that they have a software delay loop. However, if you feel adventurous, you can replace the 8048 with an 8748. The 8748 is an 8048 but has an EPROM instead of a mask programmed ROM. If you call up the Laser people I'm sure they'll tell you the location to change. And it is very easy to burn an 8748, and they only cost a few bucks.. Jonathan A. Chandross Internet: jac@paul.rutgers.edu UUCP: rutgers!paul.rutgers.edu!jac