laverman@cs.rug.nl (Bert Laverman) (06/12/91)
Dear all, For some time now my trusty ol' Model 4 is standing unused because of a rather unfortunate problem with it's CRT controller. Rather soon after their introduction of the M4 the entire line of Z80 based machines already started to be dropped. I bought my M4 from a non-Tandy vendor who happened to have some of the last machines for sale, only to find out things could get worse. Some time ago the display started acting up: the image flickered up and down. Cooling down, warming up, replacing certain small chips: nothing helped. I started calling those few people remaining in the Netherlands that were known to repair M4's, and one of them gave me the diagnosis: CRTC blown. Appearently my machine is second hand, and has been 'upgraded' during it's former life. This 'upgrade' consisted of the replacement of the Z80 by some NEC chip, and notching the clock speed up. The hacker explained there was one known problem with this upgrade: the CRTC can't handle the higher clock speed. Since my motherboard is changed, replacing the CRTC will not solve the problem. Also a problem is it's price: ca. 120 US$. I'm told I can get the Model 3 to Model 4 upgrade for this price, and that includes a complete motherboard. It's rumored that this M3->M4 upgrade is still sold in the US. Can anyone give me conclusive info on this? Greetings, Bert -- #include <std/disclaimer> ---------------------------------------------------------------------- Bert Laverman, Dept. of Computing Science, Groningen University laverman@cs.rug.nl bert@arrakis.nl.mugnet.org