Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!aramis.rutgers.edu!paul.rutgers.edu!jac From: jac@paul.rutgers.edu (J. A. Chandross) Newsgroups: comp.sys.apple Subject: Re: [QUESTION]: How to speed up the LASER 128 repeat-key... Message-ID: Date: 7 Jun 89 01:53:50 GMT References: <18970@cup.portal.com> <378@h.cs.wvu.wvnet.edu> Distribution: na Organization: Rutgers Univ., New Brunswick, N.J. Lines: 20 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